Buildouts ========= The word "buildout" refers to a description of a set of parts and the software to create and assemble them. It is often used informally to refer to an installed system based on a buildout definition. For example, if we are creating an application named "Foo", then "the Foo buildout" is the collection of configuration and application-specific software that allows an instance of the application to be created. We may refer to such an instance of the application informally as "a Foo buildout". This document describes how to define buildouts using buildout configuration files and recipes. There are three ways to set up the buildout software and create a buildout instance: 1. Install the ``zc.buildout`` egg with ``easy_install`` and use the buildout script installed in a Python scripts area. 2. Use the buildout bootstrap script to create a buildout that includes both the ``setuptools`` and ``zc.buildout`` eggs. This allows you to use the buildout software without modifying a Python install. The buildout script is installed into your buildout local scripts area. 3. Use a buildout command from an already installed buildout to bootstrap a new buildout. (See the section on bootstrapping later in this document.) Often, a software project will be managed in a software repository, such as a subversion repository, that includes some software source directories, buildout configuration files, and a copy of the buildout bootstrap script. To work on the project, one would check out the project from the repository and run the bootstrap script which installs ``setuptools`` and ``zc.buildout`` into the checkout as well as any parts defined. We have a sample buildout that we created using the bootstrap command of an existing buildout (method 3 above). It has the absolute minimum information. We have ``bin``, ``develop-eggs``, ``eggs`` and ``parts`` directories, and a configuration file:: >>> ls(sample_buildout) d bin - buildout.cfg d develop-eggs d eggs d parts The ``bin`` directory contains scripts:: >>> ls(sample_buildout, 'bin') - buildout The ``eggs`` directory has installed distributions: >>> ls(sample_buildout, 'eggs') - pip.egg-link - setuptools.egg-link - wheel.egg-link - zc.buildout.egg-link The ``develop-eggs`` and ``parts`` directories are initially empty:: >>> ls(sample_buildout, 'develop-eggs') >>> ls(sample_buildout, 'parts') The ``develop-eggs`` directory holds egg links for software being developed in the buildout. We separate ``develop-eggs`` and other eggs to allow eggs directories to be shared across multiple buildouts. For example, a common developer technique is to define a common eggs directory in their home that all non-develop eggs are stored in. This allows larger buildouts to be set up much more quickly and saves disk space. The ``parts`` directory provides an area where recipes can install part data. For example, if we built a custom Python, we would install it in the ``parts`` directory. Part data is stored in a sub-directory of the parts directory with the same name as the part. Buildouts are defined using configuration files. These are in the format defined by the Python ``ConfigParser`` module, with extensions that we'll describe later. By default, when a buildout is run, it looks for the file ``buildout.cfg`` in the directory where the buildout is run. The minimal configuration file has a ``buildout`` section that defines no parts:: >>> cat(sample_buildout, 'buildout.cfg') [buildout] parts = A part is simply something to be created by a buildout. It can be almost anything, such as a Python package, a program, a directory, or even a configuration file. Recipes ------- A part is created by a recipe. Recipes are always installed as Python eggs. They can be downloaded from a package server, such as the Python Package Index, or they can be developed as part of a project using a "develop" egg. A develop egg is a special kind of egg that gets installed as an "egg link" that contains the name of a source directory. Develop eggs don't have to be packaged for distribution to be used and can be modified in place, which is especially useful while they are being developed. Let's create a recipe as part of the sample project. We'll create a recipe for creating directories. First, we'll create a recipes source directory for our local recipes:: >>> mkdir(sample_buildout, 'recipes') and then we'll create a source file for our ``mkdir`` recipe:: >>> write(sample_buildout, 'recipes', 'mkdir.py', ... """ ... import logging, os, zc.buildout ... ... class Mkdir: ... ... def __init__(self, buildout, name, options): ... self.name, self.options = name, options ... options['path'] = os.path.join( ... buildout['buildout']['directory'], ... options['path'], ... ) ... if not os.path.isdir(os.path.dirname(options['path'])): ... logging.getLogger(self.name).error( ... 'Cannot create %s. %s is not a directory.', ... options['path'], os.path.dirname(options['path'])) ... raise zc.buildout.UserError('Invalid Path') ... ... ... def install(self): ... path = self.options['path'] ... logging.getLogger(self.name).info( ... 'Creating directory %s', os.path.basename(path)) ... os.mkdir(path) ... return path ... ... def update(self): ... pass ... """) Currently, recipes must define 3 methods: - a constructor, - an install method, and - an update method. The constructor is responsible for updating a parts options to reflect data read from other sections. The buildout system keeps track of whether a part specification has changed. A part specification has changed if it's options, after adjusting for data read from other sections, has changed, or if the recipe has changed. Only the options for the part are considered. If data are read from other sections, then that information has to be reflected in the parts options. In the ``mkdir`` example, the given path is interpreted relative to the buildout directory, and data from the buildout directory is read. The path option is updated to reflect this. If the directory option was changed in the buildout sections, we would know to update parts created using the ``mkdir`` recipe using relative path names. When buildout is run, it saves configuration data for installed parts in a file named ``.installed.cfg``. In subsequent runs, it compares part-configuration data stored in the ``.installed.cfg`` file and the part-configuration data loaded from the configuration files as modified by recipe constructors to decide if the configuration of a part has changed. If the configuration has changed, or if the recipe has changed, then the part is uninstalled and reinstalled. The buildout only looks at the part's options, so any data used to configure the part needs to be reflected in the part's options. It is the job of a recipe constructor to make sure that the options include all relevant data. Of course, parts are also uninstalled if they are no longer used. The recipe defines a constructor that takes a buildout object, a part name, and an options dictionary. It saves them in instance attributes. If the path is relative, we'll interpret it as relative to the buildout directory. The buildout object passed in is a mapping from section name to a mapping of options for that section. The buildout directory is available as the directory option of the buildout section. We normalize the path and save it back into the options directory. The install method is responsible for creating the part. In this case, we need the path of the directory to create. We'll use a path option from our options dictionary. The install method logs what it's doing using the Python ``logging`` call. We return the path that we installed. If the part is uninstalled or reinstalled, then the path returned will be removed by the buildout machinery. A recipe install method is expected to return a string, or an iterable of strings containing paths to be removed if a part is uninstalled. For most recipes, this is all of the uninstall support needed. For more complex uninstallation scenarios, use `Uninstall recipes`_. The update method is responsible for updating an already installed part. An empty method is often provided, as in this example, if parts can't be updated. An update method can return None, a string, or an iterable of strings. If a string or iterable of strings is returned, then the saved list of paths to be uninstalled is updated with the new information by adding any new files returned by the update method. We need to provide packaging information so that our recipe can be installed as a develop egg. The minimum information we need to specify is a name. For recipes, we also need to define the names of the recipe classes as entry points. Packaging information is provided via a ``setup.py`` script:: >>> write(sample_buildout, 'recipes', 'setup.py', ... """ ... from setuptools import setup ... ... setup( ... name = "recipes", ... entry_points = {'zc.buildout': ['mkdir = mkdir:Mkdir']}, ... ) ... """) Our setup script defines an *entry point*. Entry points provide a way for an egg to define the services it provides. Here we've said that we define a ``zc.buildout`` entry point named ``mkdir``. Recipe classes must be exposed as entry points in the ``zc.buildout`` group. We give entry points names within the group. We also need a ``README.txt`` for our recipes to avoid an annoying warning from ``distutils`` (which ``setuptools`` and ``zc.buildout`` are based on):: >>> write(sample_buildout, 'recipes', 'README.txt', " ") Now let's update our ``buildout.cfg``:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = data-dir ... ... [data-dir] ... recipe = recipes:mkdir ... path = mystuff ... """) Let's go through the changes one by one:: develop = recipes This tells the buildout to install a development egg for our recipes. Any number of paths can be listed. The paths can be relative or absolute. If relative, they are treated as relative to the buildout directory. They can be directory or file paths. If a file path is given, it should point to a Python setup script. If a directory path is given, it should point to a directory containing a ``setup.py`` file. Development eggs are installed before building any parts, as they may provide locally-defined recipes needed by the parts. :: parts = data-dir Here we've named a part to be "built". We can use any name we want, except that part names have to be unique and recipes will often use the part name to decide what to do. :: [data-dir] recipe = recipes:mkdir path = mystuff When we name a part, we also create a section of the same name that contains part data. In this section, we'll define the recipe to be used to install the part. In this case, we also specify the path to be created. Let's run the buildout. We do so by running the build script in the buildout:: >>> import os >>> os.chdir(sample_buildout) >>> buildout = os.path.join(sample_buildout, 'bin', 'buildout') >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Installing data-dir. data-dir: Creating directory mystuff We see that the recipe created the directory, as expected:: >>> ls(sample_buildout) - .installed.cfg d bin - buildout.cfg d develop-eggs d eggs d mystuff d parts d recipes In addition, .installed.cfg has been created containing information about the part we installed:: >>> cat(sample_buildout, '.installed.cfg') [buildout] installed_develop_eggs = /sample-buildout/develop-eggs/recipes.egg-link parts = data-dir <BLANKLINE> [data-dir] __buildout_installed__ = /sample-buildout/mystuff __buildout_signature__ = recipes-c7vHV6ekIDUPy/7fjAaYjg== path = /sample-buildout/mystuff recipe = recipes:mkdir Note that the directory we installed is included in .installed.cfg. In addition, the path option includes the actual destination directory. If we change the name of the directory in the configuration file, we'll see that the directory gets removed and recreated:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = data-dir ... ... [data-dir] ... recipe = recipes:mkdir ... path = mydata ... """) >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling data-dir. Installing data-dir. data-dir: Creating directory mydata >>> ls(sample_buildout) - .installed.cfg d bin - buildout.cfg d develop-eggs d eggs d mydata d parts d recipes If any of the files or directories created by a recipe are removed, the part will be reinstalled:: >>> rmdir(sample_buildout, 'mydata') >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling data-dir. Installing data-dir. data-dir: Creating directory mydata Error reporting --------------- If a user makes an error the error needs to be reported, and work needs to stop. This is accomplished by logging a detailed error message and then raising a ``zc.buildout.UserError`` exception (or a subclass of this exception). Raising an error other than a ``UserError`` still displays the error, but labels it as a bug in the buildout software or recipe. In the sample above, if someone gives a non-existent directory to create the directory in:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = data-dir ... ... [data-dir] ... recipe = recipes:mkdir ... path = /xxx/mydata ... """) we'll get a user error, not a traceback:: >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' data-dir: Cannot create .../xxx/mydata. .../xxx is not a directory. While: Installing. Getting section data-dir. Initializing section data-dir. Error: Invalid Path Recipe Error Handling --------------------- If an error occurs during installation, it is up to the recipe to clean up any system side effects, such as files created. Let's update the ``mkdir`` recipe to support multiple paths:: >>> write(sample_buildout, 'recipes', 'mkdir.py', ... """ ... import logging, os, zc.buildout ... ... class Mkdir: ... ... def __init__(self, buildout, name, options): ... self.name, self.options = name, options ... ... # Normalize paths and check that their parent ... # directories exist: ... paths = [] ... for path in options['path'].split(): ... path = os.path.join(buildout['buildout']['directory'], path) ... if not os.path.isdir(os.path.dirname(path)): ... logging.getLogger(self.name).error( ... 'Cannot create %s. %s is not a directory.', ... options['path'], os.path.dirname(options['path'])) ... raise zc.buildout.UserError('Invalid Path') ... paths.append(path) ... options['path'] = ' '.join(paths) ... ... def install(self): ... paths = self.options['path'].split() ... for path in paths: ... logging.getLogger(self.name).info( ... 'Creating directory %s', os.path.basename(path)) ... os.mkdir(path) ... return paths ... ... def update(self): ... pass ... """) .. >>> clean_up_pyc(sample_buildout, 'recipes', 'mkdir.py') If there is an error creating a path, the install method will exit and leave previously created paths in place:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = data-dir ... ... [data-dir] ... recipe = recipes:mkdir ... path = foo bin ... """) >>> print_(system(buildout)) # doctest: +ELLIPSIS Develop: '/sample-buildout/recipes' Uninstalling data-dir. Installing data-dir. data-dir: Creating directory foo data-dir: Creating directory bin While: Installing data-dir. <BLANKLINE> An internal error occurred due to a bug in either zc.buildout or in a recipe being used: Traceback (most recent call last): ... exists... We meant to create a directory ``bins``, but typed ``bin``. Now ``foo`` was left behind:: >>> os.path.exists('foo') True If we fix the typo:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = data-dir ... ... [data-dir] ... recipe = recipes:mkdir ... path = foo bins ... """) >>> print_(system(buildout)) # doctest: +ELLIPSIS Develop: '/sample-buildout/recipes' Installing data-dir. data-dir: Creating directory foo While: Installing data-dir. <BLANKLINE> An internal error occurred due to a bug in either zc.buildout or in a recipe being used: Traceback (most recent call last): ... exists... Now they fail because ``foo`` exists, because it was left behind:: >>> remove('foo') Let's fix the recipe:: >>> write(sample_buildout, 'recipes', 'mkdir.py', ... """ ... import logging, os, zc.buildout, sys ... ... class Mkdir: ... ... def __init__(self, buildout, name, options): ... self.name, self.options = name, options ... ... # Normalize paths and check that their parent ... # directories exist: ... paths = [] ... for path in options['path'].split(): ... path = os.path.join(buildout['buildout']['directory'], path) ... if not os.path.isdir(os.path.dirname(path)): ... logging.getLogger(self.name).error( ... 'Cannot create %s. %s is not a directory.', ... options['path'], os.path.dirname(options['path'])) ... raise zc.buildout.UserError('Invalid Path') ... paths.append(path) ... options['path'] = ' '.join(paths) ... ... def install(self): ... paths = self.options['path'].split() ... created = [] ... try: ... for path in paths: ... logging.getLogger(self.name).info( ... 'Creating directory %s', os.path.basename(path)) ... os.mkdir(path) ... created.append(path) ... except Exception: ... for d in created: ... os.rmdir(d) ... assert not os.path.exists(d) ... logging.getLogger(self.name).info( ... 'Removed %s due to error', ... os.path.basename(d)) ... sys.stderr.flush() ... sys.stdout.flush() ... raise ... ... return paths ... ... def update(self): ... pass ... """) .. >>> clean_up_pyc(sample_buildout, 'recipes', 'mkdir.py') And put back the typo:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = data-dir ... ... [data-dir] ... recipe = recipes:mkdir ... path = foo bin ... """) When we rerun the buildout:: >>> print_(system(buildout)) # doctest: +ELLIPSIS Develop: '/sample-buildout/recipes' Installing data-dir. data-dir: Creating directory foo data-dir: Creating directory bin data-dir: Removed foo due to error While: Installing data-dir. <BLANKLINE> An internal error occurred due to a bug in either zc.buildout or in a recipe being used: Traceback (most recent call last): ... exists... we get the same error, but we don't get the directory left behind:: >>> os.path.exists('foo') False It's critical that recipes clean up partial effects when errors occur. Because recipes most commonly create files and directories, buildout provides a helper API for removing created files when an error occurs. Option objects have a ``created`` method that can be called to record files as they are created. If the ``install`` or ``update`` method returns with an error, then any registered paths are removed automatically. The method returns the files registered and can be used to return the files created. Let's use this API to simplify the recipe:: >>> write(sample_buildout, 'recipes', 'mkdir.py', ... """ ... import logging, os, zc.buildout ... ... class Mkdir: ... ... def __init__(self, buildout, name, options): ... self.name, self.options = name, options ... ... # Normalize paths and check that their parent ... # directories exist: ... paths = [] ... for path in options['path'].split(): ... path = os.path.join(buildout['buildout']['directory'], path) ... if not os.path.isdir(os.path.dirname(path)): ... logging.getLogger(self.name).error( ... 'Cannot create %s. %s is not a directory.', ... options['path'], os.path.dirname(options['path'])) ... raise zc.buildout.UserError('Invalid Path') ... paths.append(path) ... options['path'] = ' '.join(paths) ... ... def install(self): ... paths = self.options['path'].split() ... for path in paths: ... logging.getLogger(self.name).info( ... 'Creating directory %s', os.path.basename(path)) ... os.mkdir(path) ... self.options.created(path) ... ... return self.options.created() ... ... def update(self): ... pass ... """) .. >>> clean_up_pyc(sample_buildout, 'recipes', 'mkdir.py') We returned by calling ``created``, taking advantage of the fact that it returns the registered paths. We did this for illustrative purposes. It would be simpler to just return the paths as before. If we rerun the buildout again, we'll get the error and no directories will be created:: >>> print_(system(buildout)) # doctest: +ELLIPSIS Develop: '/sample-buildout/recipes' Installing data-dir. data-dir: Creating directory foo data-dir: Creating directory bin While: Installing data-dir. <BLANKLINE> An internal error occurred due to a bug in either zc.buildout or in a recipe being used: Traceback (most recent call last): ... exists... >>> os.path.exists('foo') False Now, we'll fix the typo again and we'll get the directories we expect:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = data-dir ... ... [data-dir] ... recipe = recipes:mkdir ... path = foo bins ... """) >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Installing data-dir. data-dir: Creating directory foo data-dir: Creating directory bins >>> os.path.exists('foo') True >>> os.path.exists('bins') True Configuration file syntax ------------------------- A buildout configuration file consists of a sequence of sections. A section has a *section header* followed by 0 or more *section options*. (Buildout configuration files may be viewed as a variation on INI files.) A section header consists of a section name enclosed in square braces. A section name consists of one or more non-whitespace characters other than square braces (``[``, ``]``), curly braces (``{``, ``}``), colons (``:``) or equal signs (``=``). Whitespace surrounding section names is ignored. A section header can optionally have a condition expression separated by a colon. See `Conditional sections`_. Options consist of option names, followed by optional space or tab characters, an optional plus or minus sign and an equal sign and values. An option value may be spread over multiple lines as long as the lines after the first start with a whitespace character. An option name consists of one or more non-whitespace characters other than equal signs, square braces (``[``, ``]``), curly braces (``{``, ``}``), plus signs or colons (``:``). The option name ``<`` is reserved. An option's data consists of the characters following the equal sign on the start line, plus the continuation lines. Option values have extra whitespace stripped. How this is done depends on whether the value has non-whitespace characters on the first line. If an option value has non-whitespace characters on the first line, then each line is stripped and blank lines are removed. For example, in:: [foo] bar = 1 baz = a b c .. -> text >>> try: import StringIO ... except ImportError: import io as StringIO >>> import pprint, zc.buildout.configparser >>> pprint.pprint(zc.buildout.configparser.parse(StringIO.StringIO( ... text), 'test')) {'foo': {'bar': '1', 'baz': 'a\nb\nc'}} The value of of ``bar`` is ``'1'`` and the value of ``baz`` is ``'a\nb\nc'``. If the first line of an option does **not** contain whitespace, then the value is dedented (with ``textwrap.dedent``), trailing spaces in lines are removed, and leading and trailing blank lines are removed. For example, in:: [foo] bar = baz = a b c .. -> text >>> pprint.pprint(zc.buildout.configparser.parse(StringIO.StringIO( ... text), 'test')) {'foo': {'bar': '', 'baz': 'a\n b\n\nc'}} The value of bar is ``''``, and the value of baz is ``'a\n b\n\nc'``. Lines starting with ``#`` or ``;`` characters are comments. Comments can also be placed after the closing square bracket (``]``) in a section header. Buildout configuration data are Python strings, which are bytes in Python 2 and unicode in Python 3. Sections and options within sections may be repeated. Multiple occurrences of a section are treated as if they were concatenated. The last option value for a given name in a section overrides previous values. In addition to the syntactic details above: - option names are case sensitive - option values can use a substitution syntax, described below, to refer to option values in specific sections. - option values can be appended or removed using the - and + operators. Annotated sections ------------------ When used with the ``annotate`` command, buildout displays annotated sections. All sections are displayed, sorted alphabetically. For each section, all key-value pairs are displayed, sorted alphabetically, along with the origin of the value (file name or ``COMPUTED_VALUE``, ``DEFAULT_VALUE``, ``COMMAND_LINE_VALUE``):: >>> print_(system(buildout+ ' annotate'), end='') ... # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE <BLANKLINE> Annotated sections ================== <BLANKLINE> [buildout] allow-hosts= * DEFAULT_VALUE allow-picked-versions= true DEFAULT_VALUE allow-unknown-extras= false DEFAULT_VALUE bin-directory= bin DEFAULT_VALUE develop= recipes buildout.cfg develop-eggs-directory= develop-eggs DEFAULT_VALUE directory= /sample-buildout COMPUTED_VALUE eggs-directory= /sample-buildout/eggs DEFAULT_VALUE executable= ... DEFAULT_VALUE find-links= DEFAULT_VALUE install-from-cache= false DEFAULT_VALUE installed= .installed.cfg DEFAULT_VALUE log-format= DEFAULT_VALUE log-level= INFO DEFAULT_VALUE newest= true DEFAULT_VALUE offline= false DEFAULT_VALUE parts= data-dir buildout.cfg parts-directory= parts DEFAULT_VALUE prefer-final= true DEFAULT_VALUE python= buildout DEFAULT_VALUE show-picked-versions= false DEFAULT_VALUE socket-timeout= DEFAULT_VALUE update-versions-file= DEFAULT_VALUE use-dependency-links= true DEFAULT_VALUE versions= versions DEFAULT_VALUE <BLANKLINE> [data-dir] path= foo bins buildout.cfg recipe= recipes:mkdir buildout.cfg <BLANKLINE> [versions] zc.buildout = >=1.99 DEFAULT_VALUE zc.recipe.egg = >=1.99 DEFAULT_VALUE <BLANKLINE> The ``annotate`` command is sensitive to the verbosity flag. You get more information about the way values are computed:: >>> print_(system(buildout+ ' -v annotate'), end='') ... # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE <BLANKLINE> Annotated sections ================== <BLANKLINE> [buildout] allow-hosts= * <BLANKLINE> AS DEFAULT_VALUE SET VALUE = * <BLANKLINE> allow-picked-versions= true <BLANKLINE> AS DEFAULT_VALUE SET VALUE = true <BLANKLINE> allow-unknown-extras= false <BLANKLINE> AS DEFAULT_VALUE SET VALUE = false <BLANKLINE> bin-directory= bin <BLANKLINE> AS DEFAULT_VALUE SET VALUE = bin <BLANKLINE> develop= recipes <BLANKLINE> IN buildout.cfg SET VALUE = recipes <BLANKLINE> develop-eggs-directory= develop-eggs <BLANKLINE> AS DEFAULT_VALUE SET VALUE = develop-eggs <BLANKLINE> directory= /sample-buildout <BLANKLINE> AS COMPUTED_VALUE SET VALUE = /sample-buildout <BLANKLINE> eggs-directory= /sample-buildout/eggs <BLANKLINE> AS DEFAULT_VALUE DIRECTORY VALUE = /sample-buildout/eggs AS DEFAULT_VALUE SET VALUE = eggs <BLANKLINE> executable= ... <BLANKLINE> AS DEFAULT_VALUE SET VALUE = ... <BLANKLINE> find-links= <BLANKLINE> AS DEFAULT_VALUE SET VALUE = <BLANKLINE> install-from-cache= false <BLANKLINE> AS DEFAULT_VALUE SET VALUE = false <BLANKLINE> installed= .installed.cfg <BLANKLINE> AS DEFAULT_VALUE SET VALUE = .installed.cfg <BLANKLINE> log-format= <BLANKLINE> AS DEFAULT_VALUE SET VALUE = <BLANKLINE> log-level= INFO <BLANKLINE> AS DEFAULT_VALUE SET VALUE = INFO <BLANKLINE> newest= true <BLANKLINE> AS DEFAULT_VALUE SET VALUE = true <BLANKLINE> offline= false <BLANKLINE> AS DEFAULT_VALUE SET VALUE = false <BLANKLINE> parts= data-dir <BLANKLINE> IN buildout.cfg SET VALUE = data-dir <BLANKLINE> parts-directory= parts <BLANKLINE> AS DEFAULT_VALUE SET VALUE = parts <BLANKLINE> prefer-final= true <BLANKLINE> AS DEFAULT_VALUE SET VALUE = true <BLANKLINE> python= buildout <BLANKLINE> AS DEFAULT_VALUE SET VALUE = buildout <BLANKLINE> show-picked-versions= false <BLANKLINE> AS DEFAULT_VALUE SET VALUE = false <BLANKLINE> socket-timeout= <BLANKLINE> AS DEFAULT_VALUE SET VALUE = <BLANKLINE> update-versions-file= <BLANKLINE> AS DEFAULT_VALUE SET VALUE = <BLANKLINE> use-dependency-links= true <BLANKLINE> AS DEFAULT_VALUE SET VALUE = true <BLANKLINE> verbosity= 10 <BLANKLINE> AS COMMAND_LINE_VALUE SET VALUE = 10 <BLANKLINE> versions= versions <BLANKLINE> AS DEFAULT_VALUE SET VALUE = versions <BLANKLINE> <BLANKLINE> [data-dir] path= foo bins <BLANKLINE> IN buildout.cfg SET VALUE = foo bins <BLANKLINE> recipe= recipes:mkdir <BLANKLINE> IN buildout.cfg SET VALUE = recipes:mkdir <BLANKLINE> <BLANKLINE> [versions] ... The output of the ``annotate`` command can be very long. You can restrict the output to some sections by passing section names as arguments:: >>> print_(system(buildout+ ' annotate versions'), end='') ... # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE <BLANKLINE> Annotated sections ================== <BLANKLINE> [versions] zc.buildout= >=1.99 DEFAULT_VALUE zc.recipe.egg= >=1.99 DEFAULT_VALUE <BLANKLINE> Query values ------------ For continuous integration, it might be useful to query the buildout config. >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = . ... ... [values] ... host = buildout.org ... multiline = ... first ... second ... """) >>> print_(system(buildout+ ' query buildout:develop'), end='') . >>> print_(system(buildout+ ' query values:host'), end='') buildout.org >>> print_(system(buildout+ ' query values:multiline'), end='') first second As with assignments, if the section is omitted, 'buildout' section is assumed. >>> print_(system(buildout+ ' query develop'), end='') . When used with -v option, the query command also displays section and key. >>> print_(system(buildout+ ' -v query develop'), end='') ${buildout:develop} . >>> print_(system(buildout+ ' -v query values:host'), end='') ${values:host} buildout.org The query commands outputs proper error messages. >>> print_(system(buildout+ ' query versions parts'), end='') Error: The query command requires a single argument. >>> print_(system(buildout+ ' query'), end='') Error: The query command requires a single argument. >>> print_(system(buildout+ ' query invalid:section:key'), end='') Error: Invalid option: invalid:section:key >>> print_(system(buildout+ ' -v query values:port'), end='') ${values:port} Error: Key not found: port >>> print_(system(buildout+ ' -v query versionx'), end='') ${buildout:versionx} Error: Key not found: versionx >>> print_(system(buildout+ ' -v query specific:port'), end='') ${specific:port} Error: Section not found: specific Variable substitutions ---------------------- Buildout configuration files support variable substitution. To illustrate this, we'll create an debug recipe to allow us to see interactions with the buildout:: >>> write(sample_buildout, 'recipes', 'debug.py', ... """ ... import sys ... class Debug: ... ... def __init__(self, buildout, name, options): ... self.buildout = buildout ... self.name = name ... self.options = options ... ... def install(self): ... for option, value in sorted(self.options.items()): ... sys.stdout.write('%s %s\\n' % (option, value)) ... return () ... ... update = install ... """) >>> write(sample_buildout, 'recipes', 'environ.py', ... """ ... import sys ... import os ... class Environ: ... ... def __init__(self, buildout, name, options): ... self.buildout = buildout ... self.options = options ... ... def install(self): ... _ = self.options['name'] ... sys.stdout.write('HOME %s\\n' % os.environ['HOME']) ... sys.stdout.write('USERPROFILE %s\\n' % os.environ['USERPROFILE']) ... sys.stdout.write('expanduser %s\\n' % os.path.expanduser('~')) ... return () ... ... update = install ... """) This recipe doesn't actually create anything. The install method doesn't return anything, because it didn't create any files or directories. We also have to update our setup script:: >>> write(sample_buildout, 'recipes', 'setup.py', ... """ ... from setuptools import setup ... entry_points = ( ... ''' ... [zc.buildout] ... mkdir = mkdir:Mkdir ... debug = debug:Debug ... environ = environ:Environ ... ''') ... setup(name="recipes", entry_points=entry_points, py_modules=['debug', 'environ']) ... """) We've rearranged the script a bit to make the entry points easier to edit. Specifically, entry points are now defined as a configuration string, rather than a dictionary. Let's update our configuration to provide variable substitution examples:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = data-dir debug ... log-level = INFO ... ... [debug] ... recipe = recipes:debug ... File-1 = ${data-dir:path}/file ... File-2 = ${debug:File-1}/log ... ... [data-dir] ... recipe = recipes:mkdir ... path = mydata ... """) We used a string-template substitution for ``File-1`` and ``File-2``. This type of substitution uses the ``string.Template`` syntax. Names substituted are qualified option names, consisting of a section name and option name joined by a colon. Now, if we run the buildout, we'll see the options with the values substituted:: >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling data-dir. Installing data-dir. data-dir: Creating directory mydata Installing debug. File-1 /sample-buildout/mydata/file File-2 /sample-buildout/mydata/file/log recipe recipes:debug Note that the substitution of the ``data-dir`` path option reflects the update to the option performed by the ``mkdir`` recipe. It might seem surprising that ``mydata`` was created again. This is because we changed our ``recipes`` package by adding the ``debug`` module. The buildout system didn't know if this module could affect the ``mkdir`` recipe, so it assumed it could and reinstalled ``mydata``. If we rerun the buildout:: >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Updating data-dir. Updating debug. File-1 /sample-buildout/mydata/file File-2 /sample-buildout/mydata/file/log recipe recipes:debug we can see that ``mydata`` was not recreated. Note that, in this case, we didn't specify a log level, so we didn't get output about what the buildout was doing. Section and option names in variable substitutions are only allowed to contain alphanumeric characters, hyphens, periods and spaces. This restriction might be relaxed in future releases. We can omit the section name in a variable substitution to refer to the current section. We can also use the special option, ``_buildout_section_name_`` to get the current section name:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = data-dir debug ... log-level = INFO ... ... [debug] ... recipe = recipes:debug ... File-1 = ${data-dir:path}/file ... File-2 = ${:File-1}/log ... my_name = ${:_buildout_section_name_} ... ... [data-dir] ... recipe = recipes:mkdir ... path = mydata ... """) >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Updating data-dir. Installing debug. File-1 /sample-buildout/mydata/file File-2 /sample-buildout/mydata/file/log my_name debug recipe recipes:debug Automatic part selection and ordering ------------------------------------- When a section with a recipe is referred to, either through variable substitution or by an initializing recipe, the section is treated as a part and added to the part list before the referencing part. For example, we can leave ``data-dir`` out of the parts list:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = debug ... log-level = INFO ... ... [debug] ... recipe = recipes:debug ... File-1 = ${data-dir:path}/file ... File-2 = ${debug:File-1}/log ... ... [data-dir] ... recipe = recipes:mkdir ... path = mydata ... """) It will still be treated as a part:: >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Updating data-dir. Installing debug. File-1 /sample-buildout/mydata/file File-2 /sample-buildout/mydata/file/log recipe recipes:debug >>> cat('.installed.cfg') # doctest: +ELLIPSIS [buildout] installed_develop_eggs = /sample-buildout/develop-eggs/recipes.egg-link parts = data-dir debug ... Note that the ``data-dir`` part is included *before* the ``debug`` part, because the ``debug`` part refers to the ``data-dir`` part. Even if we list the ``data-dir`` part after the ``debug`` part, it will be included before:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = debug data-dir ... log-level = INFO ... ... [debug] ... recipe = recipes:debug ... File-1 = ${data-dir:path}/file ... File-2 = ${debug:File-1}/log ... ... [data-dir] ... recipe = recipes:mkdir ... path = mydata ... """) It will still be treated as a part:: >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Updating data-dir. Updating debug. File-1 /sample-buildout/mydata/file File-2 /sample-buildout/mydata/file/log recipe recipes:debug >>> cat('.installed.cfg') # doctest: +ELLIPSIS [buildout] installed_develop_eggs = /sample-buildout/develop-eggs/recipes.egg-link parts = data-dir debug ... Extending sections (macros) --------------------------- A section (other than the buildout section) can extend one or more other sections using the ``<`` option. Options from the referenced sections are copied to the referring section *before* variable substitution. This, together with the ability to refer to variables of the current section, allows sections to be used as macros:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = myfiles ... log-level = INFO ... ... [debug] ... recipe = recipes:debug ... ... [with_file1] ... <= debug ... file1 = ${:path}/file1 ... color = red ... ... [with_file2] ... <= debug ... file2 = ${:path}/file2 ... color = blue ... ... [myfiles] ... <= with_file1 ... with_file2 ... path = mydata ... """) >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Uninstalling data-dir. Installing myfiles. color blue file1 mydata/file1 file2 mydata/file2 path mydata recipe recipes:debug In this example, the ``debug``, ``with_file1`` and ``with_file2`` sections act as macros. In particular, the variable substitutions are performed relative to the ``myfiles`` section. .. note:: Don't be fooled by the appearance of the ``<= section`` lines --- though ``<=`` may look like a new operator, it's still just the familiar ``key = value`` syntax. .. cleanup buildout >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = ... """) >>> _ = system(buildout) Extending sections (macros) - Adding and removing options --------------------------------------------------------- We can also add and remove options in extended sections. This is illustrated below; first we define a base configuration. >>> write(sample_buildout, 'base.cfg', ... """ ... [buildout] ... parts = part1 part2 part3 ... ... [part1] ... recipe = ... option = a1 ... a2 ... ... [part2] ... <= part1 ... option -= a1 ... option += c3 c4 ... ... [part3] ... <= part2 ... option += d2 ... c5 d1 d6 ... option -= a2 ... """) To verify that the options are adjusted correctly, we'll set up an extension that prints out the options. >>> mkdir(sample_buildout, 'demo') >>> write(sample_buildout, 'demo', 'demo.py', ... """ ... import sys ... def ext(buildout): ... sys.stdout.write(str( ... [part['option'] for name, part in sorted(buildout.items()) ... if name.startswith('part')])+'\\n') ... """) >>> write(sample_buildout, 'demo', 'setup.py', ... """ ... from setuptools import setup ... ... setup( ... name="demo", ... entry_points={'zc.buildout.extension': ['ext = demo:ext']}, ... ) ... """) Set up a buildout configuration for this extension. >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = demo ... parts = ... """) >>> os.chdir(sample_buildout) >>> print_(system(os.path.join(sample_buildout, 'bin', 'buildout')), end='') # doctest: +ELLIPSIS Develop: '/sample-buildout/demo' Verify option values. >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = demo ... extensions = demo ... extends = base.cfg ... """) >>> print_(system(os.path.join('bin', 'buildout')), end='') ['a1/na2', 'a2/nc3 c4', 'c3 c4/nd2/nc5 d1 d6'] Develop: '/sample-buildout/demo' Cleanup. >>> os.remove(os.path.join(sample_buildout, 'base.cfg')) >>> rmdir(sample_buildout, 'demo') Adding and removing options --------------------------- We can append and remove values to an option by using the ``+`` and ``-`` operators. This is illustrated below; first we define a base configuration:: >>> write(sample_buildout, 'base.cfg', ... """ ... [buildout] ... parts = part1 part2 part3 ... ... [part1] ... recipe = ... option = a1 a2 ... ... [part2] ... recipe = ... option = b1 b2 b3 b4 ... ... [part3] ... recipe = ... option = c1 c2 ... ... [part4] ... recipe = ... option = d2 ... d3 ... d5 ... ... """) Extending this configuration, we can "adjust" the values set in the base configuration file:: >>> write(sample_buildout, 'extension1.cfg', ... """ ... [buildout] ... extends = base.cfg ... ... # appending values ... [part1] ... option += a3 a4 ... ... # removing values ... [part2] ... option -= b1 b2 ... ... # alt. spelling ... [part3] ... option+=c3 c4 c5 ... ... # combining both adding and removing ... [part4] ... option += d1 ... d4 ... option -= d5 ... ... # normal assignment ... [part5] ... option = h1 h2 ... ... """) An additional extension:: >>> write(sample_buildout, 'extension2.cfg', ... """ ... [buildout] ... extends = extension1.cfg ... ... # appending values ... [part1] ... option += a5 ... ... # removing values ... [part2] ... option -= b1 b2 b3 ... ... """) To verify that the options are adjusted correctly, we'll set up an extension that prints out the options:: >>> mkdir(sample_buildout, 'demo') >>> write(sample_buildout, 'demo', 'demo.py', ... """ ... import sys ... def ext(buildout): ... sys.stdout.write(str( ... [part['option'] for name, part in sorted(buildout.items()) ... if name.startswith('part')])+'\\n') ... """) >>> write(sample_buildout, 'demo', 'setup.py', ... """ ... from setuptools import setup ... ... setup( ... name="demo", ... entry_points={'zc.buildout.extension': ['ext = demo:ext']}, ... ) ... """) Set up a buildout configuration for this extension:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = demo ... parts = ... """) >>> os.chdir(sample_buildout) >>> print_(system(os.path.join(sample_buildout, 'bin', 'buildout')), end='') ... # doctest: +ELLIPSIS Develop: '/sample-buildout/demo'... Verify option values:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = demo ... extensions = demo ... extends = extension2.cfg ... """) >>> print_(system(os.path.join('bin', 'buildout')), end='') ['a1 a2/na3 a4/na5', 'b1 b2 b3 b4', 'c1 c2/nc3 c4 c5', 'd2/nd3/nd1/nd4', 'h1 h2'] Develop: '/sample-buildout/demo' Annotated sections output shows which files are responsible for which operations:: >>> print_(system(os.path.join('bin', 'buildout') + ' annotate'), end='') ... # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE <BLANKLINE> Annotated sections ================== ... <BLANKLINE> [part1] option= a1 a2 a3 a4 a5 base.cfg += extension1.cfg += extension2.cfg recipe= base.cfg <BLANKLINE> [part2] option= b1 b2 b3 b4 base.cfg -= extension1.cfg -= extension2.cfg recipe= base.cfg <BLANKLINE> [part3] option= c1 c2 c3 c4 c5 base.cfg += extension1.cfg recipe= base.cfg <BLANKLINE> [part4] option= d2 d3 d1 d4 base.cfg += extension1.cfg -= extension1.cfg recipe= base.cfg <BLANKLINE> [part5] option= h1 h2 extension1.cfg [versions] zc.buildout= >=1.99 DEFAULT_VALUE zc.recipe.egg= >=1.99 DEFAULT_VALUE <BLANKLINE> With more verbosity:: >>> print_(system(os.path.join('bin', 'buildout') + ' -v annotate'), end='') ... # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE <BLANKLINE> Annotated sections ================== ... [part1] option= a1 a2 a3 a4 a5 <BLANKLINE> IN extension2.cfg ADD VALUE = a5 IN extension1.cfg ADD VALUE = a3 a4 IN base.cfg SET VALUE = a1 a2 <BLANKLINE> ... [part2] option= b1 b2 b3 b4 <BLANKLINE> IN extension2.cfg REMOVE VALUE = b1 b2 b3 IN extension1.cfg REMOVE VALUE = b1 b2 IN base.cfg SET VALUE = b1 b2 b3 b4 <BLANKLINE> ... [part3] option= c1 c2 c3 c4 c5 <BLANKLINE> IN extension1.cfg ADD VALUE = c3 c4 c5 IN base.cfg SET VALUE = c1 c2 <BLANKLINE> ... [part4] option= d2 d3 d1 d4 <BLANKLINE> IN extension1.cfg REMOVE VALUE = d5 IN extension1.cfg ADD VALUE = d1 d4 IN base.cfg SET VALUE = d2 d3 d5 <BLANKLINE> ... [part5] option= h1 h2 <BLANKLINE> IN extension1.cfg SET VALUE = h1 h2 <BLANKLINE> ... Cleanup:: >>> os.remove(os.path.join(sample_buildout, 'base.cfg')) >>> os.remove(os.path.join(sample_buildout, 'extension1.cfg')) >>> os.remove(os.path.join(sample_buildout, 'extension2.cfg')) Multiple configuration files ---------------------------- A configuration file can *extend* another configuration file. Options are read from the other configuration file if they aren't already defined by your configuration file. The configuration files your file extends can extend other configuration files. The same file may be used more than once although, of course, cycles aren't allowed. To see how this works, we use an example:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... extends = base.cfg ... ... [debug] ... op = buildout ... """) >>> write(sample_buildout, 'base.cfg', ... """ ... [buildout] ... develop = recipes ... parts = debug ... ... [debug] ... recipe = recipes:debug ... op = base ... """) >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Installing debug. op buildout recipe recipes:debug The example is pretty trivial, but the pattern it illustrates is pretty common. In a more practical example, the base buildout might represent a product and the extending buildout might be a customization. Here is a more elaborate example:: >>> other = tmpdir('other') >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... extends = b1.cfg b2.cfg %(b3)s ... ... [debug] ... op = buildout ... """ % dict(b3=os.path.join(other, 'b3.cfg'))) >>> write(sample_buildout, 'b1.cfg', ... """ ... [buildout] ... extends = base.cfg ... ... [debug] ... op1 = b1 1 ... op2 = b1 2 ... """) >>> write(sample_buildout, 'b2.cfg', ... """ ... [buildout] ... extends = base.cfg ... ... [debug] ... op2 = b2 2 ... op3 = b2 3 ... """) >>> write(other, 'b3.cfg', ... """ ... [buildout] ... extends = b3base.cfg ... ... [debug] ... op4 = b3 4 ... """) >>> write(other, 'b3base.cfg', ... """ ... [debug] ... op5 = b3base 5 ... """) >>> write(sample_buildout, 'base.cfg', ... """ ... [buildout] ... develop = recipes ... parts = debug ... ... [debug] ... recipe = recipes:debug ... name = base ... ... [environ] ... recipe = recipes:environ ... name = base ... """) >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Installing debug. name base op buildout op1 b1 1 op2 b2 2 op3 b2 3 op4 b3 4 op5 b3base 5 recipe recipes:debug There are several things to note about this example: - We can name multiple files in an ``extends`` option. - We can reference files recursively. - Relative file names in extended options are interpreted relative to the directory containing the referencing configuration file. >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... extends = b1.cfg ... ... [debug] ... op = buildout ... """) >>> print_(system(buildout + ' buildout:extends="b2.cfg"'), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Installing debug. name base op buildout op1 b1 1 op2 b2 2 op3 b2 3 recipe recipes:debug >>> print_(system(buildout + ' buildout:extends="b2.cfg %(b3)s"' ... % dict(b3=os.path.join(other, 'b3.cfg'))), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Installing debug. name base op buildout op1 b1 1 op2 b2 2 op3 b2 3 op4 b3 4 op5 b3base 5 recipe recipes:debug >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... extends = b1.cfg b2.cfg %(b3)s ... ... [debug] ... op = buildout ... """ % dict(b3=os.path.join(other, 'b3.cfg'))) Loading Configuration from URLs ------------------------------- Configuration files can be loaded from URLs. To see how this works, we'll set up a web server with some configuration files:: >>> server_data = tmpdir('server_data') >>> write(server_data, "r1.cfg", ... """ ... [debug] ... op1 = r1 1 ... op2 = r1 2 ... """) >>> write(server_data, "r2.cfg", ... """ ... [buildout] ... extends = r1.cfg ... ... [debug] ... op2 = r2 2 ... op3 = r2 3 ... """) >>> server_url = start_server(server_data) >>> write('client.cfg', ... """ ... [buildout] ... develop = recipes ... parts = debug ... extends = %(url)s/r2.cfg ... ... [debug] ... recipe = recipes:debug ... name = base ... """ % dict(url=server_url)) >>> print_(system(buildout+ ' -c client.cfg'), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Installing debug. name base op1 r1 1 op2 r2 2 op3 r2 3 recipe recipes:debug Here we specified a URL for the file we extended. The file we downloaded itself referred to a file on the server using a relative URL reference. Relative references are interpreted relative to the base URL when they appear in configuration files loaded via URL. We can also specify a URL as the configuration file to be used by a buildout:: >>> os.remove('client.cfg') >>> write(server_data, 'remote.cfg', ... """ ... [buildout] ... develop = recipes ... parts = debug ... extends = r2.cfg ... ... [debug] ... recipe = recipes:debug ... name = remote ... """) >>> print_(system(buildout + ' -c ' + server_url + '/remote.cfg'), end='') While: Initializing. Error: Missing option: buildout:directory Normally, the buildout directory defaults to a directory containing a configuration file. This won't work for configuration files loaded from URLs. In this case, the buildout directory would normally be defined on the command line:: >>> print_(system(buildout ... + ' -c ' + server_url + '/remote.cfg' ... + ' buildout:directory=' + sample_buildout ... ), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Installing debug. name remote op1 r1 1 op2 r2 2 op3 r2 3 recipe recipes:debug User defaults ------------- If the file ``$HOME/.buildout/default.cfg`` exists, it is read before reading the configuration file. (``$HOME`` is the value of the ``HOME`` environment variable. The ``/`` is replaced by the operating system file delimiter.):: >>> home = tmpdir('home') >>> mkdir(home, '.buildout') >>> default_cfg = join(home, '.buildout', 'default.cfg') >>> write(default_cfg, ... """ ... [debug] ... op1 = 1 ... op7 = 7 ... """) >>> env = dict(HOME=home, USERPROFILE=home) >>> print_(system(buildout, env=env), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Installing debug. name base op buildout op1 b1 1 op2 b2 2 op3 b2 3 op4 b3 4 op5 b3base 5 op7 7 recipe recipes:debug A buildout command-line argument, ``-U``, can be used to suppress reading user defaults:: >>> print_(system(buildout + ' -U', env=env), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Installing debug. name base op buildout op1 b1 1 op2 b2 2 op3 b2 3 op4 b3 4 op5 b3base 5 recipe recipes:debug If the environment variable ``BUILDOUT_HOME`` is non-empty, that is used to locate ``default.cfg`` instead of looking in ``~/.buildout/``. Let's set up a configuration file in an alternate directory and verify that we get the appropriate set of defaults:: >>> alterhome = tmpdir('alterhome') >>> write(alterhome, 'default.cfg', ... """ ... [debug] ... op1 = 1' ... op7 = 7' ... op8 = eight! ... """) >>> env['BUILDOUT_HOME'] = alterhome >>> print_(system(buildout, env=env), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Installing debug. name base op buildout op1 b1 1 op2 b2 2 op3 b2 3 op4 b3 4 op5 b3base 5 op7 7' op8 eight! recipe recipes:debug The ``-U`` argument still suppresses reading of the ``default.cfg`` file from ``BUILDOUT_HOME``:: >>> print_(system(buildout + ' -U', env=env), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Installing debug. name base op buildout op1 b1 1 op2 b2 2 op3 b2 3 op4 b3 4 op5 b3base 5 recipe recipes:debug Log level --------- We can control the level of logging by specifying a log level in our configuration file. For example, to suppress info messages, we can set the logging level to *WARNING*:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... log-level = WARNING ... extends = b1.cfg b2.cfg ... """) >>> print_(system(buildout), end='') name base op1 b1 1 op2 b2 2 op3 b2 3 recipe recipes:debug Socket timeout -------------- The timeout of the connections to egg and configuration servers can be configured in the buildout section. Its value is configured in seconds:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... socket-timeout = 5 ... develop = recipes ... parts = debug ... ... [debug] ... recipe = recipes:debug ... op = timeout ... """) >>> print_(system(buildout), end='') Setting socket time out to 5 seconds. Develop: '/sample-buildout/recipes' Uninstalling debug. Installing debug. op timeout recipe recipes:debug If the ``socket-timeout`` is not numeric, a warning is issued and the default timeout of the Python socket module is used:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... socket-timeout = 5s ... develop = recipes ... parts = debug ... ... [debug] ... recipe = recipes:debug ... op = timeout ... """) >>> print_(system(buildout), end='') Default socket timeout is used ! Value in configuration is not numeric: [5s]. <BLANKLINE> Develop: '/sample-buildout/recipes' Updating debug. op timeout recipe recipes:debug Uninstall recipes ----------------- As we've seen, when parts are installed, buildout keeps track of files and directories that they create. When the parts are uninstalled these files and directories are deleted. Sometimes more clean-up is needed. For example, a recipe might add a system service by calling ``chkconfig --add`` during installation. Later during uninstallation, ``chkconfig --del`` will need to be called to remove the system service. In order to deal with these uninstallation issues, you can register uninstall recipes. Uninstall recipes are registered using the ``zc.buildout.uninstall`` entry point. Parts specify uninstall recipes using the ``uninstall`` option. In comparison to regular recipes, uninstall recipes are much simpler. They are simply callable objects that accept the name of the part to be uninstalled and the part's options dictionary. Uninstall recipes don't have access to the part itself since it may be impossible to instantiate at uninstallation time. Here's a recipe that simulates installation of a system service, along with an uninstall recipe that simulates removing the service:: >>> write(sample_buildout, 'recipes', 'service.py', ... """ ... import sys ... class Service: ... ... def __init__(self, buildout, name, options): ... self.buildout = buildout ... self.name = name ... self.options = options ... ... def install(self): ... sys.stdout.write("chkconfig --add %s\\n" ... % self.options['script']) ... return () ... ... def update(self): ... pass ... ... ... def uninstall_service(name, options): ... sys.stdout.write("chkconfig --del %s\\n" % options['script']) ... """) To use these recipes we must register them using entry points. Make sure to use the same name for the recipe and uninstall recipe. This is required to let buildout know which uninstall recipe goes with which recipe:: >>> write(sample_buildout, 'recipes', 'setup.py', ... """ ... from setuptools import setup ... entry_points = ( ... ''' ... [zc.buildout] ... mkdir = mkdir:Mkdir ... debug = debug:Debug ... service = service:Service ... ... [zc.buildout.uninstall] ... service = service:uninstall_service ... ''') ... setup(name="recipes", entry_points=entry_points, py_modules=['debug', 'environ', 'service']) ... """) Here's how these recipes could be used in a buildout:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = service ... ... [service] ... recipe = recipes:service ... script = /path/to/script ... """) When the buildout is run the service will be installed:: >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Installing service. chkconfig --add /path/to/script The service has been installed. If the buildout is run again with no changes, the service shouldn't be changed:: >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Updating service. Now we change the service part to trigger uninstallation and re-installation:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = service ... ... [service] ... recipe = recipes:service ... script = /path/to/a/different/script ... """) >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling service. Running uninstall recipe. chkconfig --del /path/to/script Installing service. chkconfig --add /path/to/a/different/script Now we remove the service part, and add another part:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = debug ... ... [debug] ... recipe = recipes:debug ... """) >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling service. Running uninstall recipe. chkconfig --del /path/to/a/different/script Installing debug. recipe recipes:debug Uninstall recipes don't have to take care of removing all the files and directories created by the part. This is still done automatically, following the execution of the uninstall recipe. An upshot is that an uninstallation recipe can access files and directories created by a recipe before they are deleted. For example, here's an uninstallation recipe that simulates backing up a directory before it is deleted. It is designed to work with the ``mkdir`` recipe introduced earlier:: >>> write(sample_buildout, 'recipes', 'backup.py', ... """ ... import os, sys ... def backup_directory(name, options): ... path = options['path'] ... size = len(os.listdir(path)) ... sys.stdout.write("backing up directory %s of size %s\\n" ... % (path, size)) ... """) It must be registered with the ``zc.buildout.uninstall`` entry point. Notice how it is given the name ``mkdir`` to associate it with the ``mkdir`` recipe:: >>> write(sample_buildout, 'recipes', 'setup.py', ... """ ... from setuptools import setup ... entry_points = ( ... ''' ... [zc.buildout] ... mkdir = mkdir:Mkdir ... debug = debug:Debug ... service = service:Service ... ... [zc.buildout.uninstall] ... uninstall_service = service:uninstall_service ... mkdir = backup:backup_directory ... ''') ... setup(name="recipes", entry_points=entry_points, py_modules=['debug', 'environ', 'service', 'backup']) ... """) Now we can use it with a ``mkdir`` part:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = dir debug ... ... [dir] ... recipe = recipes:mkdir ... path = my_directory ... ... [debug] ... recipe = recipes:debug ... """) Run the buildout to install the part:: >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Installing dir. dir: Creating directory my_directory Installing debug. recipe recipes:debug Now we remove the part from the configuration file:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = debug ... ... [debug] ... recipe = recipes:debug ... """) When the buildout is run the part is removed, and the uninstall recipe is run before the directory is deleted:: >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling dir. Running uninstall recipe. backing up directory /sample-buildout/my_directory of size 0 Updating debug. recipe recipes:debug Now we will return the registration to normal for the benefit of the rest of the examples:: >>> write(sample_buildout, 'recipes', 'setup.py', ... """ ... from setuptools import setup ... entry_points = ( ... ''' ... [zc.buildout] ... mkdir = mkdir:Mkdir ... debug = debug:Debug ... ''') ... setup(name="recipes", entry_points=entry_points, py_modules=['debug', 'environ', 'service', 'backup']) ... """) Command-line usage ------------------ A number of arguments can be given on the buildout command line. The command usage is:: buildout [options and assignments] [command [command arguments]] The following options are supported: ``-h`` (or ``--help``) Print basic usage information. If this option is used, then all other options are ignored. ``-c`` filename The ``-c`` option can be used to specify a configuration file, rather than ``buildout.cfg`` in the current directory. ``-t`` socket_timeout Specify the socket timeout in seconds. ``-v`` Increment the verbosity by 10. The verbosity is used to adjust the logging level. The verbosity is subtracted from the numeric value of the log-level option specified in the configuration file. ``-q`` Decrement the verbosity by 10. ``-U`` Don't read user-default configuration. ``-o`` Run in off-line mode. This is equivalent to the assignment ``buildout:offline=true``. ``-O`` Run in non-off-line mode. This is equivalent to the assignment ``buildout:offline=false``. This is the default buildout mode. The ``-O`` option would normally be used to override a true offline setting in a configuration file. ``-n`` Run in newest mode. This is equivalent to the assignment ``buildout:newest=true``. With this setting, which is the default, buildout will try to find the newest versions of distributions available that satisfy its requirements. ``-N`` Run in non-newest mode. This is equivalent to the assignment ``buildout:newest=false``. With this setting, buildout will not seek new distributions if installed distributions satisfy its requirements. Assignments are of the form:: section_name:option_name=value or:: option_name=value which is equivalent to:: buildout:option_name=value Options and assignments can be given in any order. Here's an example:: >>> write(sample_buildout, 'other.cfg', ... """ ... [buildout] ... develop = recipes ... parts = debug ... installed = .other.cfg ... log-level = WARNING ... ... [debug] ... name = other ... recipe = recipes:debug ... """) Note that we used the installed buildout option to specify an alternate file to store information about installed parts:: >>> print_(system(buildout+' -c other.cfg debug:op1=foo -v'), end='') Develop: '/sample-buildout/recipes' Installing debug. name other op1 foo recipe recipes:debug Here we used the ``-c`` option to specify an alternate configuration file, and the ``-v`` option to increase the level of logging from the default, *WARNING*. Options can also be combined in the usual Unix way, as in:: >>> print_(system(buildout+' -vcother.cfg debug:op1=foo'), end='') Develop: '/sample-buildout/recipes' Updating debug. name other op1 foo recipe recipes:debug Here we combined the ``-v`` and ``-c`` options with the configuration file name. Note that the ``-c`` option has to be last, because it takes an argument:: >>> os.remove(os.path.join(sample_buildout, 'other.cfg')) >>> os.remove(os.path.join(sample_buildout, '.other.cfg')) The most commonly used command is ``install``, and it takes a list of parts to install. If any parts are specified, only those parts are installed. To illustrate this, we'll update our configuration and run the buildout in the usual way:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = debug d1 d2 d3 ... ... [d1] ... recipe = recipes:mkdir ... path = d1 ... ... [d2] ... recipe = recipes:mkdir ... path = d2 ... ... [d3] ... recipe = recipes:mkdir ... path = d3 ... ... [debug] ... recipe = recipes:debug ... """) >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling debug. Installing debug. recipe recipes:debug Installing d1. d1: Creating directory d1 Installing d2. d2: Creating directory d2 Installing d3. d3: Creating directory d3 >>> ls(sample_buildout) - .installed.cfg - b1.cfg - b2.cfg - base.cfg d bin - buildout.cfg d d1 d d2 d d3 d demo d develop-eggs d eggs d parts d recipes >>> cat(sample_buildout, '.installed.cfg') ... # doctest: +NORMALIZE_WHITESPACE [buildout] installed_develop_eggs = /sample-buildout/develop-eggs/recipes.egg-link parts = debug d1 d2 d3 <BLANKLINE> [debug] __buildout_installed__ = __buildout_signature__ = recipes-PiIFiO8ny5yNZ1S3JfT0xg== recipe = recipes:debug <BLANKLINE> [d1] __buildout_installed__ = /sample-buildout/d1 __buildout_signature__ = recipes-PiIFiO8ny5yNZ1S3JfT0xg== path = /sample-buildout/d1 recipe = recipes:mkdir <BLANKLINE> [d2] __buildout_installed__ = /sample-buildout/d2 __buildout_signature__ = recipes-PiIFiO8ny5yNZ1S3JfT0xg== path = /sample-buildout/d2 recipe = recipes:mkdir <BLANKLINE> [d3] __buildout_installed__ = /sample-buildout/d3 __buildout_signature__ = recipes-PiIFiO8ny5yNZ1S3JfT0xg== path = /sample-buildout/d3 recipe = recipes:mkdir Now we'll update our configuration file:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = debug d2 d3 d4 ... ... [d2] ... recipe = recipes:mkdir ... path = data2 ... ... [d3] ... recipe = recipes:mkdir ... path = data3 ... ... [d4] ... recipe = recipes:mkdir ... path = ${d2:path}-extra ... ... [debug] ... recipe = recipes:debug ... x = 1 ... """) and run the buildout specifying just ``d3`` and ``d4``:: >>> print_(system(buildout+' install d3 d4'), end='') Develop: '/sample-buildout/recipes' Uninstalling d3. Installing d3. d3: Creating directory data3 Installing d4. d4: Creating directory data2-extra >>> ls(sample_buildout) - .installed.cfg - b1.cfg - b2.cfg - base.cfg d bin - buildout.cfg d d1 d d2 d data2-extra d data3 d demo d develop-eggs d eggs d parts d recipes Only the ``d3`` and ``d4`` recipes ran. ``d3`` was removed and ``data3`` and ``data2-extra`` were created. The ``.installed.cfg`` is only updated for the recipes that ran:: >>> cat(sample_buildout, '.installed.cfg') ... # doctest: +NORMALIZE_WHITESPACE [buildout] installed_develop_eggs = /sample-buildout/develop-eggs/recipes.egg-link parts = debug d1 d2 d3 d4 <BLANKLINE> [debug] __buildout_installed__ = __buildout_signature__ = recipes-PiIFiO8ny5yNZ1S3JfT0xg== recipe = recipes:debug <BLANKLINE> [d1] __buildout_installed__ = /sample-buildout/d1 __buildout_signature__ = recipes-PiIFiO8ny5yNZ1S3JfT0xg== path = /sample-buildout/d1 recipe = recipes:mkdir <BLANKLINE> [d2] __buildout_installed__ = /sample-buildout/d2 __buildout_signature__ = recipes-PiIFiO8ny5yNZ1S3JfT0xg== path = /sample-buildout/d2 recipe = recipes:mkdir <BLANKLINE> [d3] __buildout_installed__ = /sample-buildout/data3 __buildout_signature__ = recipes-PiIFiO8ny5yNZ1S3JfT0xg== path = /sample-buildout/data3 recipe = recipes:mkdir <BLANKLINE> [d4] __buildout_installed__ = /sample-buildout/data2-extra __buildout_signature__ = recipes-PiIFiO8ny5yNZ1S3JfT0xg== path = /sample-buildout/data2-extra recipe = recipes:mkdir Note that the installed data for ``debug``, ``d1``, and ``d2`` haven't changed, because we didn't install those parts, and that the ``d1`` and ``d2`` directories are still there. Now, if we run the buildout without the install command:: >>> print_(system(buildout), end='') Develop: '/sample-buildout/recipes' Uninstalling d2. Uninstalling d1. Uninstalling debug. Installing debug. recipe recipes:debug x 1 Installing d2. d2: Creating directory data2 Updating d3. Updating d4. We see the output of the debug recipe, and that ``data2`` was created. We also see that ``d1`` and ``d2`` have gone away:: >>> ls(sample_buildout) - .installed.cfg - b1.cfg - b2.cfg - base.cfg d bin - buildout.cfg d data2 d data2-extra d data3 d demo d develop-eggs d eggs d parts d recipes Alternate directory and file locations -------------------------------------- The buildout normally puts the ``bin``, ``eggs``, and ``parts`` directories in the directory in the directory containing the configuration file. You can provide alternate locations, and even names for these directories:: >>> alt = tmpdir('sample-alt') >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = ... develop-eggs-directory = %(developbasket)s ... eggs-directory = %(basket)s ... bin-directory = %(scripts)s ... parts-directory = %(work)s ... """ % dict( ... developbasket = os.path.join(alt, 'developbasket'), ... basket = os.path.join(alt, 'basket'), ... scripts = os.path.join(alt, 'scripts'), ... work = os.path.join(alt, 'work'), ... )) >>> print_(system(buildout), end='') Creating directory '/sample-alt/basket'. Creating directory '/sample-alt/scripts'. Creating directory '/sample-alt/work'. Creating directory '/sample-alt/developbasket'. Develop: '/sample-buildout/recipes' Uninstalling d2. Uninstalling debug. Uninstalling d4. Uninstalling d3. >>> ls(alt) d basket d developbasket d scripts d work >>> ls(alt, 'developbasket') - recipes.egg-link You can also specify an alternate buildout directory:: >>> rmdir(alt) >>> alt = tmpdir('sample-alt') >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... directory = %(alt)s ... develop = %(recipes)s ... parts = ... """ % dict( ... alt=alt, ... recipes=os.path.join(sample_buildout, 'recipes'), ... )) >>> print_(system(buildout), end='') Creating directory '/sample-alt/eggs'. Creating directory '/sample-alt/bin'. Creating directory '/sample-alt/parts'. Creating directory '/sample-alt/develop-eggs'. Develop: '/sample-buildout/recipes' >>> ls(alt) - .installed.cfg d bin d develop-eggs d eggs d parts >>> ls(alt, 'develop-eggs') - recipes.egg-link Logging control --------------- Three buildout options are used to control logging: ``log-level`` specifies the log level ``verbosity`` adjusts the log level ``log-format`` allows an alternate logging format to be specified We've already seen the log level and verbosity. Let's look at an example of changing the format:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = ... log-level = 25 ... verbosity = 5 ... log-format = %(levelname)s %(message)s ... """) Here, we've changed the format to include the log-level name, rather than the logger name. We've also illustrated, with a contrived example, that the log level can be a numeric value and that the verbosity can be specified in the configuration file. Because the verbosity is subtracted from the log level, we get a final log level of 20, which is the *INFO* level:: >>> print_(system(buildout), end='') INFO Develop: '/sample-buildout/recipes' Predefined buildout options --------------------------- Buildouts have a number of predefined options that recipes can use and that users can override in their configuration files. To see these, we'll run a minimal buildout configuration with a ``debug`` logging level. One of the features of ``debug`` logging is that the configuration database is shown:: >>> write(sample_buildout, 'buildout.cfg', ... """ ... [buildout] ... parts = ... """) >>> print_(system(buildout+' -vv'), end='') # doctest: +NORMALIZE_WHITESPACE Installing 'zc.buildout', 'setuptools', 'pip', 'wheel'. ... Configuration data: [buildout] allow-hosts = * allow-picked-versions = true allow-unknown-extras = false bin-directory = /sample-buildout/bin develop-eggs-directory = /sample-buildout/develop-eggs directory = /sample-buildout eggs-directory = /sample-buildout/eggs executable = python find-links = install-from-cache = false installed = /sample-buildout/.installed.cfg log-format = log-level = INFO newest = true offline = false parts = parts-directory = /sample-buildout/parts prefer-final = true python = buildout show-picked-versions = false socket-timeout = update-versions-file = use-dependency-links = true verbosity = 20 versions = versions [versions] zc.buildout = >=1.99 zc.recipe.egg = >=1.99 <BLANKLINE> All of these options can be overridden by configuration files or by command-line assignments. We've discussed most of these options already, but let's review them and touch on some we haven't discussed: ``abi-tag-eggs`` Add an `ABI tag <https://www.python.org/dev/peps/pep-0425/#abi-tag>`_ to the directory name given by the ``eggs-directory`` option. This is useful when switching between python implementations when details of the implementation aren't reflected in egg names. It also has the side benefit of making eggs directories smaller, because eggs for different Python versions are in different directories. ``allow-hosts`` On some environments the links visited by ``zc.buildout`` can be forbidden by paranoid firewalls. These URLs might be in the chain of links visited by ``zc.buildout`` as defined by buildout's ``find-links`` option, or as defined by various eggs in their ``url``, ``download_url``, ``dependency_links`` metadata. The fact that ``package_index`` works like a spider and might visit links and go to other locations makes this even harder. The ``allow-hosts`` option provides a way to prevent this, and works exactly like the one provided in ``easy_install``. You can provide a list of allowed hosts, together with wildcards:: [buildout] ... allow-hosts = *.python.org example.com All URLs that do not match these hosts will not be visited. ``allow-picked-versions`` By default, the buildout will choose the best match for a given requirement if the requirement is not specified precisely (for instance, using the ``versions`` option. This behavior corresponds to the ``allow-picked-versions`` being set to its default value, ``true``. If ``allow-picked-versions`` is ``false``, instead of picking the best match, buildout will raise an error. This helps enforce repeatability. ``bin-directory`` The directory path where scripts are written. This can be a relative path, which is interpreted relative to the directory option. ``develop-eggs-directory`` The directory path where development egg links are created for software being created in the local project. This can be a relative path, which is interpreted relative to the directory option. ``directory`` The buildout directory. This is the base for other buildout file and directory locations, when relative locations are used. ``eggs-directory`` The directory path where downloaded eggs are put. It is common to share this directory across buildouts. This can be a relative path, which is interpreted relative to the directory option. .. warning:: Eggs in this directory should *never* be modified. ``find-links`` You can specify more locations to search for distributions using the ``find-links`` option. All locations specified will be searched for distributions along with the package index as described before. Locations can be URLs:: [buildout] ... find-links = http://download.zope.org/distribution/ They can also be directories on disk:: [buildout] ... find-links = /some/path Finally, they can also be direct paths to distributions:: [buildout] ... find-links = /some/path/someegg-1.0.0-py2.3.egg Any number of locations can be specified in the ``find-links`` option:: [buildout] ... find-links = http://download.zope.org/distribution/ /some/otherpath /some/path/someegg-1.0.0-py2.3.egg ``install-from-cache`` A download cache can be used as the basis of application source releases. In an application source release, we want to distribute an application that can be built without making any network accesses. In this case, we distribute a buildout along with a download cache, and tell the buildout to install from the download cache only, without making network accesses. The buildout ``install-from-cache`` option can be used to signal that packages should be installed only from the download cache. ``installed`` The file path where information about the results of the previous buildout run is written. This can be a relative path, which is interpreted relative to the directory option. This file provides an inventory of installed parts with information needed to decide which if any parts need to be uninstalled. ``log-format`` The format used for logging messages. ``log-level`` The log level before verbosity adjustment ``newest`` By default buildout and recipes will try to find the newest versions of distributions needed to satisfy requirements. This can be very time consuming, especially when incrementally working on setting up a buildout or working on a recipe. The buildout ``newest`` option can be used to to suppress this. If the ``newest`` option is set to false, then new distributions won't be sought if an installed distribution meets requirements. The ``newest`` option can also be set to false using the -N command-line option. See also the ``offline`` option. ``offline`` The ``offline`` option goes a bit further than the ``newest`` option. If the buildout ``offline`` option is given a value of ``true``, the buildout and recipes that are aware of the option will avoid doing network access. This is handy when running the buildout when not connected to the internet. It also makes buildouts run much faster. This option is typically set using the buildout ``-o`` option. ``parts`` A whitespace-separated list of parts to be installed. ``parts-directory`` A working directory that parts can used to store data. ``prefer-final`` Currently, when searching for new releases, the newest available release is used. This isn't usually ideal, as you may get a development release or alpha releases not ready to be widely used. You can request that final releases be preferred using the ``prefer-final`` option in the ``buildout`` section:: [buildout] ... prefer-final = true When the ``prefer-final`` option is set to ``true``, then when searching for new releases, final releases are preferred. If there are final releases that satisfy distribution requirements, then those releases are used even if newer non-final releases are available. The buildout ``prefer-final`` option can be used to override this behavior. In buildout version 2, final releases will be preferred by default. You will then need to use a ``false`` value for ``prefer-final`` to get the newest releases. ``use-dependency-links`` By default buildout will obey the setuptools ``dependency_links`` metadata when it looks for dependencies. This behavior can be controlled with the ``use-dependency-links`` buildout option:: [buildout] ... use-dependency-links = false The option defaults to ``true``. If you set it to ``false``, then dependency links are only looked for in the locations specified by ``find-links``. ``verbosity`` A log-level adjustment. Typically, this is set via the ``-q`` and ``-v`` command-line options. Creating new buildouts and bootstrapping ---------------------------------------- If ``zc.buildout`` is installed, you can use it to create a new buildout with its own local copies of ``zc.buildout`` and ``setuptools`` and with local buildout scripts:: >>> sample_bootstrapped = tmpdir('sample-bootstrapped') >>> print_(system(buildout ... +' -c'+os.path.join(sample_bootstrapped, 'setup.cfg') ... +' init'), end='') Creating '/sample-bootstrapped/setup.cfg'. Creating directory '/sample-bootstrapped/eggs'. Creating directory '/sample-bootstrapped/bin'. Creating directory '/sample-bootstrapped/parts'. Creating directory '/sample-bootstrapped/develop-eggs'. Generated script '/sample-bootstrapped/bin/buildout'. Note that a basic ``setup.cfg`` was created for us. This is because we provided an ``init`` argument. By default, the generated ``setup.cfg`` is as minimal as can be:: >>> cat(sample_bootstrapped, 'setup.cfg') [buildout] parts = We also get other buildout artifacts:: >>> ls(sample_bootstrapped) d bin d develop-eggs d eggs d parts - setup.cfg >>> ls(sample_bootstrapped, 'bin') - buildout >>> _ = (ls(sample_bootstrapped, 'eggs'), ... ls(sample_bootstrapped, 'develop-eggs')) - pip.egg-link - setuptools.egg-link - wheel.egg-link - zc.buildout.egg-link (We list both the ``eggs`` and ``develop-eggs`` directories because the buildout or setuptools egg could be installed in the ``develop-eggs`` directory if the original buildout had develop eggs for either buildout or setuptools.) Note that the buildout script was installed but not run. To run the buildout, we'd have to run the installed buildout script. If we have an existing buildout that already has a ``buildout.cfg``, we'll normally use the ``bootstrap`` command instead of ``init``. It will complain if there isn't a configuration file:: >>> sample_bootstrapped2 = tmpdir('sample-bootstrapped2') >>> print_(system(buildout ... +' -c'+os.path.join(sample_bootstrapped2, 'setup.cfg') ... +' bootstrap'), end='') While: Initializing. Error: Couldn't open /sample-bootstrapped2/setup.cfg >>> write(sample_bootstrapped2, 'setup.cfg', ... """ ... [buildout] ... parts = ... """) >>> print_(system(buildout ... +' -c'+os.path.join(sample_bootstrapped2, 'setup.cfg') ... +' bootstrap'), end='') Creating directory '/sample-bootstrapped2/eggs'. Creating directory '/sample-bootstrapped2/bin'. Creating directory '/sample-bootstrapped2/parts'. Creating directory '/sample-bootstrapped2/develop-eggs'. Generated script '/sample-bootstrapped2/bin/buildout'. Similarly, if there is a configuration file and we use the ``init`` command, we'll get an error that the configuration file already exists:: >>> print_(system(buildout ... +' -c'+os.path.join(sample_bootstrapped, 'setup.cfg') ... +' init'), end='') While: Initializing. Error: '/sample-bootstrapped/setup.cfg' already exists. Initial eggs ------------ When using the ``init`` command, you can specify distribution requirements or paths to use:: >>> cd(sample_bootstrapped) >>> remove('setup.cfg') >>> print_(system(buildout + ' -csetup.cfg init demo other ./src'), end='') Creating '/sample-bootstrapped/setup.cfg'. Getting distribution for 'zc.recipe.egg>=2.0.6'. Got zc.recipe.egg Installing py. Getting distribution for 'demo'. Got demo 0.3. Getting distribution for 'other'. Got other 1.0. Getting distribution for 'demoneeded'. Got demoneeded 1.1. Generated script '/sample-bootstrapped/bin/demo'. Generated script '/sample-bootstrapped/bin/distutilsscript'. Generated interpreter '/sample-bootstrapped/bin/py'. This causes a ``py`` part to be included that sets up a custom Python interpreter with the given requirements or paths:: >>> cat('setup.cfg') [buildout] parts = py <BLANKLINE> [py] recipe = zc.recipe.egg interpreter = py eggs = demo other extra-paths = ./src Passing requirements or paths causes the buildout to be run as part of initialization. In the example above, we got a number of distributions installed and 2 scripts generated. The first, ``demo``, was defined by the ``demo`` project. The second, ``py`` was defined by the generated configuration. It's a *custom interpreter* that behaves like a standard Python interpreter, except that it includes the specified eggs and extra paths in its Python path. We specified a source directory that didn't exist. Buildout created it for us:: >>> ls('.') - .installed.cfg d bin d develop-eggs d eggs d parts - setup.cfg d src >>> uncd() .. Make sure it works if the dir is already there: >>> cd(sample_bootstrapped) >>> _ = system(buildout + ' -csetup.cfg buildout:parts=') >>> remove('setup.cfg') >>> print_(system(buildout + ' -csetup.cfg init demo other ./src'), end='') Creating '/sample-bootstrapped/setup.cfg'. Installing py. Generated script '/sample-bootstrapped/bin/demo'. Generated script '/sample-bootstrapped/bin/distutilsscript'. Generated interpreter '/sample-bootstrapped/bin/py'. .. cleanup >>> _ = system(buildout + ' -csetup.cfg buildout:parts=') >>> uncd() Finding distributions --------------------- By default, buildout searches the Python Package Index when looking for distributions. You can, instead, specify your own index to search using the `index` option:: [buildout] ... index = https://index.example.com/ This index, or the default of https://pypi.org/simple/ if no index is specified, will always be searched for distributions unless running buildout with options that prevent searching for distributions. The latest version of the distribution that meets the requirements of the buildout will always be used. You can also specify more locations to search for distributions using the ``find-links`` option. See its description above. Controlling the installation database ------------------------------------- The buildout ``installed`` option is used to specify the file used to save information on installed parts. This option is initialized to ``.installed.cfg``, but it can be overridden in the configuration file or on the command line:: >>> write('buildout.cfg', ... """ ... [buildout] ... develop = recipes ... parts = debug ... ... [debug] ... recipe = recipes:debug ... """) >>> print_(system(buildout+' buildout:installed=inst.cfg'), end='') Develop: '/sample-buildout/recipes' Installing debug. recipe recipes:debug >>> ls(sample_buildout) - b1.cfg - b2.cfg - base.cfg d bin - buildout.cfg d demo d develop-eggs d eggs - inst.cfg d parts d recipes The installation database can be disabled by supplying an empty buildout installed option:: >>> os.remove('inst.cfg') >>> print_(system(buildout+' buildout:installed='), end='') Develop: '/sample-buildout/recipes' Installing debug. recipe recipes:debug >>> ls(sample_buildout) - b1.cfg - b2.cfg - base.cfg d bin - buildout.cfg d demo d develop-eggs d eggs d parts d recipes Note that there will be no installation database if there are no parts:: >>> write('buildout.cfg', ... """ ... [buildout] ... parts = ... """) >>> print_(system(buildout+' buildout:installed=inst.cfg'), end='') >>> ls(sample_buildout) - b1.cfg - b2.cfg - base.cfg d bin - buildout.cfg d demo d develop-eggs d eggs d parts d recipes Extensions ---------- A feature allows code to be loaded and run *after* configuration files have been read, but *before* the buildout has begun any processing. The intent is to allow special plugins such as ``urllib2`` request handlers to be loaded. To load an extension we use the ``extensions`` option and list one or more distribution requirements, on separate lines. The distributions named will be loaded and any ``zc.buildout.extension`` entry points found will be called with the buildout as an argument. When buildout finishes processing, any ``zc.buildout.unloadextension`` entry points found will be called with the buildout as an argument. Let's create a sample extension in our sample buildout created in the previous section:: >>> mkdir(sample_bootstrapped, 'demo') >>> write(sample_bootstrapped, 'demo', 'demo.py', ... """ ... import sys ... def ext(buildout): ... sys.stdout.write('%s %s\\n' % ('ext', sorted(buildout))) ... def unload(buildout): ... sys.stdout.write('%s %s\\n' % ('unload', sorted(buildout))) ... """) >>> write(sample_bootstrapped, 'demo', 'setup.py', ... """ ... from setuptools import setup ... ... setup( ... name = "demo", ... entry_points = { ... 'zc.buildout.extension': ['ext = demo:ext'], ... 'zc.buildout.unloadextension': ['ext = demo:unload'], ... }, ... ) ... """) Our extension just prints out the word 'demo', and lists the sections found in the buildout passed to it. We'll update our ``buildout.cfg`` to list the demo directory as a develop egg to be built:: >>> write(sample_bootstrapped, 'buildout.cfg', ... """ ... [buildout] ... develop = demo ... parts = ... """) >>> os.chdir(sample_bootstrapped) >>> print_(system(os.path.join(sample_bootstrapped, 'bin', 'buildout')), ... end='') Develop: '/sample-bootstrapped/demo' Now we can add the ``extensions`` option. We were a bit tricky and ran the buildout once with the demo develop egg defined but without the extension option. This is because extensions are loaded before the buildout creates develop eggs. We needed to use a separate buildout run to create the develop egg. Normally, when eggs are loaded from the network, we wouldn't need to do anything special. :: >>> write(sample_bootstrapped, 'buildout.cfg', ... """ ... [buildout] ... develop = demo ... extensions = demo ... parts = ... """) We see that our extension is loaded and executed:: >>> print_(system(os.path.join(sample_bootstrapped, 'bin', 'buildout')), ... end='') ext ['buildout', 'versions'] Develop: '/sample-bootstrapped/demo' unload ['buildout', 'versions'] .. >>> stop_server(server_url)