XXX software/dnsresolver: Introduce

XXX:
 * cover with tests
 * split to stack to eventually use the local v4 access
 * add proper README.rst
 * add missing udp listening promise

software/dnsresolver/buildout.hash.cfg

+[instance.cfg]
+filename = instance.cfg
+md5sum = 3e2af9c20d3b7035994885531cc82345

software/dnsresolver/instance-input-schema.json

+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "type": "object",
+  "additionalProperties": false,
+  "properties": {
+    "nameserver-list": {
+      "description": "List of nameservers to use",
+      "items": {
+        "type": "string"
+      },
+      "uniqueItems": true,
+      "type": "array"
+    },
+    "cache-size": {
+      "description": "Size of the entry cache",
+      "type": "number",
+      "default": 5000
+    }
+  }
+}

software/dnsresolver/instance-output-schema.json

+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "description": "Values returned by instanciation",
+  "properties": {
+    "dnsresolver-v6": {
+      "description": "IPv6 address of the resolver",
+      "type": "string",
+      "format": "uri"
+    },
+    "dnsresolver-v4": {
+      "description": "IPv4 address of the resolver",
+      "type": "string",
+      "format": "uri"
+    }
+  },
+  "type": "object"
+}

software/dnsresolver/instance.cfg

+[buildout]
+parts =
+  dnsmasq-service
+  dnsmasq-promise-v6
+  dnsmasq-promise-v4
+  publish-connection-parameter
+
+eggs-directory = ${buildout:eggs-directory}
+develop-eggs-directory = ${buildout:develop-eggs-directory}
+offline = true
+extends = ${monitor2-template:output}
+
+[directory]
+recipe = slapos.cookbook:mkdirectory
+home = $${buildout:directory}
+etc = $${:home}/etc/
+var = $${:home}/var/
+run = $${:var}/run/
+bin = $${:home}/bin/
+services = $${:etc}/service/
+
+[instance-parameter]
+recipe = slapos.cookbook:slapconfiguration
+computer = $${slap-connection:computer-id}
+partition = $${slap-connection:partition-id}
+url = $${slap-connection:server-url}
+key = $${slap-connection:key-file}
+cert = $${slap-connection:cert-file}
+
+[slap-configuration]
+recipe = slapos.cookbook:slapconfiguration.serialised
+computer = $${slap-connection:computer-id}
+partition = $${slap-connection:partition-id}
+url = $${slap-connection:server-url}
+key = $${slap-connection:key-file}
+cert = $${slap-connection:cert-file}
+
+[publish-connection-parameter]
+recipe = slapos.cookbook:publish.serialised
+dnsresolver-v6 = [$${slap-configuration:ipv6-random}]:$${dnsmasq-service:port}
+dnsresolver-v4 = $${slap-configuration:ipv4-random}:$${dnsmasq-service:port}
+
+[dnsmasq-config]
+recipe = slapos.recipe.template:jinja2
+output = $${directory:etc}/dnsmasq.conf
+port = 5353
+context =
+  key configuration slap-configuration:configuration
+inline =
+  port=$${:port}
+  listen-address=$${slap-configuration:ipv6-random}
+  listen-address=$${slap-configuration:ipv4-random}
+  {%- for nameserver in configuration['nameserver-list'] %}
+  server={{ nameserver }}
+  {%- endfor %}
+  cache-size={{ configuration.get('cache-size', 5000) }}
+  bind-interfaces
+  no-resolv
+  keep-in-foreground
+
+[dnsmasq-service]
+recipe = slapos.cookbook:wrapper
+command-line = ${dnsmasq-output:dnsmasq} -C $${dnsmasq-config:output}
+hash-existing-files = $${buildout:directory}/buildout.cfg
+hash-files = $${dnsmasq-config:output}
+wrapper-path = $${directory:services}/dnsmasq
+port = $${dnsmasq-config:port}
+
+[dnsmasq-promise-v6]
+<= monitor-promise-base
+promise = check_socket_listening
+name = dnsmasq-v6.py
+config-host = $${slap-configuration:ipv6-random}
+config-port = $${dnsmasq-service:port}
+
+[dnsmasq-promise-v4]
+<= dnsmasq-promise-v6
+name = dnsmasq-v4.py
+config-host = $${slap-configuration:ipv4-random}

software/dnsresolver/software.cfg

+[buildout]
+extends =
+  buildout.hash.cfg
+  ../../stack/slapos.cfg
+  ../../component/dnsmasq/buildout.cfg
+  ../../stack/monitor/buildout.cfg
+
+parts =
+  instance.cfg
+  slapos-cookbook
+
+[instance.cfg]
+recipe = slapos.recipe.template
+url = ${:_profile_base_location_}/${:filename}
+output = ${buildout:directory}/instance.cfg

software/dnsresolver/software.cfg.json

+{
+  "name": "DNS Resolver",
+  "description": "DNS Resolver using dnsmasq, for reliable DNS service",
+  "serialisation": "json-in-xml",
+  "software-type": {
+    "default": {
+      "title": "Default",
+      "software-type": "default",
+      "description": "Default",
+      "request": "instance-input-schema.json",
+      "response": "instance-output-schema.json",
+      "index": 1
+    }
+  }
+}