helloworld & helloweb: Ruby version

To illustrate how to build Ruby software, let's add helloweb-ruby
component and integrate it into helloworld SR as a service.

helloweb-ruby installation is a bit tricky, because we do not have it
initially as a released gem, and have to build it with Bundler by hand.

Changes for integration into helloworld services infrastructure are
small, thanks for the "kind" rework we did in previous patch.

/cc @kazuhiko

component/helloweb/buildout.cfg

@@ -2,9 +2,11 @@
 [buildout]
 extends =
   ../git/buildout.cfg
+  ../ruby/buildout.cfg
 
 parts =
   helloweb-python
+  helloweb-ruby
 
 
 # repository with examples
@@ -12,7 +14,7 @@ parts =
 recipe  = slapos.recipe.build:gitclone
 git-executable = ${git:location}/bin/git
 repository = https://lab.nexedi.com/nexedi/helloweb.git
-revision = 686dd5dd623728750ec30514173a7be36fab3a06
+revision = 7f5e49a541ae7b51da034dcdf20b91b64f4fb0e9
 location = ${buildout:parts-directory}/helloweb
 
 
@@ -26,3 +28,53 @@ setup   = ${helloweb-repository:location}/python/
 recipe  = zc.recipe.egg:scripts
 eggs    = ${helloweb-egg:egg}
 scripts = helloweb=helloweb-python
+
+
+# -*- ruby -*-
+
+# if ruby program is represented as already-released gem, we can install it
+# with `gem install ...` (via rubygemsrecipe).
+#
+# Alternatively if we need to
+# install the program from source-checkout, the Ruby way is to use bundler,
+# install program dependencies via it, and run the program itself via it.
+#
+# Since for helloweb.rb we have source checkout - we go the second - bundler way.
+
+# bundler, that we'll use to install gems and run binaries (via `bundle exec ...`)
+[bundler]
+# rubygemsrecipe with fixed url and this way pinned rubygems version
+recipe  = rubygemsrecipe
+url     = https://rubygems.org/rubygems/rubygems-2.4.8.zip
+ruby-location = ${ruby2.1:location}
+ruby-executable = ${:ruby-location}/bin/ruby
+gems    = bundler==1.10.6
+
+# bin installed here
+bundle  = ${buildout:bin-directory}/bundle
+
+# install together with path to ruby enabled
+# ( reason: rubygemsrecipe hardcodes PATH inside generated bin/* and it is
+#   impossible to adjust it later )
+#
+# bundle exec <smth>                ; <smth> starts with `#!/usr/bin/env ruby` as rubygems
+environment =
+  PATH    = ${:ruby-location}/bin:%(PATH)s
+
+
+[helloweb-ruby-bundle]
+recipe  = slapos.recipe.cmmi
+path    = ${helloweb-repository:location}/ruby/
+
+configure-command = :
+make-binary =
+make-targets= cd ${:path} && ${bundler:bundle} install
+
+
+[helloweb-ruby]
+recipe  = slapos.cookbook:wrapper
+wrapper-path = ${buildout:bin-directory}/${:_buildout_section_name_}
+environment  =
+    BUNDLE_GEMFILE = ${helloweb-ruby-bundle:path}/Gemfile
+command-line =
+    ${bundler:bundle} exec sh -c 'helloweb.rb "$@"' ${:_buildout_section_name_}

software/helloworld/instance.cfg.in

@@ -109,6 +109,7 @@ port    = {{ port }}
 
 # services instantiation
 {{ hellowebsrv('python', 7777) }}
+{{ hellowebsrv('ruby',   7778) }}
 
 
 # register all services/promises to buildout parts

software/helloworld/software.cfg

@@ -21,6 +21,7 @@ parts =
 
 # build helloweb programs
   helloweb-python
+  helloweb-ruby
 
 
 # Download instance.cfg.in (buildout profile used to deployment of instance),
@@ -31,7 +32,7 @@ recipe = slapos.recipe.template:jinja2
 template = ${:_profile_base_location_}/instance.cfg.in
 rendered = ${buildout:directory}/instance.cfg
 # MD5 checksum can be skipped for development (easier to develop), but must be filled for production
-md5sum = dc11d4d87edda76189ddd88a35265f05
+md5sum = be7f930921376b3c8eb51c975e24721f
 mode = 0644
 extensions = jinja2.ext.do
 context =