Go support

For upcoming GitLab SR we need Go[1] language support, because one
GitLab service is written in this language:

    https://gitlab.com/gitlab-org/gitlab-workhorse

Here we provide golang component, and helloweb-go service integrated
into helloworld SR.

The patches are based on recent helloworld & helloweb restructuring (see !23).

/reviewed-by @jerome  (on !24)
/cc @kazuhiko, @rafael, @alain.takoudjou, @gabriel, @Camata

[1] http://golang.org

component/golang/buildout.cfg

+# Go language - https://golang.org/
+[buildout]
+parts = golang
+
+[golang]
+<= golang15
+
+
+[golang-common]
+recipe = slapos.recipe.cmmi
+configure-command = :
+location = ${buildout:parts-directory}/${:_buildout_section_name_}
+make-binary =
+make-targets= cd src && ./all.bash && cp -alf .. ${:location}
+environment =
+  GOROOT_FINAL=${:location}
+  ${:environment-extra}
+
+
+[golang14]
+<= golang-common
+url = https://storage.googleapis.com/golang/go1.4.3.src.tar.gz
+md5sum = dfb604511115dd402a77a553a5923a04
+environment-extra =
+
+
+[golang15]
+<= golang-common
+url = https://storage.googleapis.com/golang/go1.5.1.src.tar.gz
+md5sum = 4adfbdfca523cc1c229be8a321f3602f
+
+# go1.5 needs go1.4 to bootstrap
+environment-extra =
+  GOROOT_BOOTSTRAP=${golang14:location}

component/helloweb/buildout.cfg

@@ -3,10 +3,12 @@
 extends =
   ../git/buildout.cfg
   ../ruby/buildout.cfg
+  ../golang/buildout.cfg
 
 parts =
   helloweb-python
   helloweb-ruby
+  helloweb-go
 
 
 # repository with examples
@@ -14,7 +16,7 @@ parts =
 recipe  = slapos.recipe.build:gitclone
 git-executable = ${git:location}/bin/git
 repository = https://lab.nexedi.com/nexedi/helloweb.git
-revision = 7f5e49a541ae7b51da034dcdf20b91b64f4fb0e9
+revision = 0487fa7bc88e83ce8b97d784ab11354aa8fac603
 location = ${buildout:parts-directory}/helloweb
 
 
@@ -78,3 +80,17 @@ environment  =
     BUNDLE_GEMFILE = ${helloweb-ruby-bundle:path}/Gemfile
 command-line =
     ${bundler:bundle} exec sh -c 'helloweb.rb "$@"' ${:_buildout_section_name_}
+
+
+# -*- go -*-
+[helloweb-go]
+recipe  = slapos.recipe.cmmi
+path    = ${helloweb-repository:location}/go/
+
+go      = ${golang15:location}/bin/go
+configure-command = :
+make-binary =
+make-targets= cd ${:path} &&
+     ${:go} build
+        -o ${buildout:bin-directory}/${:_buildout_section_name_}
+        helloweb.go

software/helloworld/instance.cfg.in

@@ -110,6 +110,7 @@ port    = {{ port }}
 # services instantiation
 {{ hellowebsrv('python', 7777) }}
 {{ hellowebsrv('ruby',   7778) }}
+{{ hellowebsrv('go',     7779) }}
 
 
 # register all services/promises to buildout parts

software/helloworld/software.cfg

@@ -22,6 +22,7 @@ parts =
 # build helloweb programs
   helloweb-python
   helloweb-ruby
+  helloweb-go
 
 
 # Download instance.cfg.in (buildout profile used to deployment of instance),
@@ -32,7 +33,7 @@ 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 = be7f930921376b3c8eb51c975e24721f
+md5sum = 6567f8dedb5cdd93542dc29e96edb547
 mode = 0644
 extensions = jinja2.ext.do
 context =