gitlab: 8.0.5 -> 8.5.0, service improvements

Updates gitlab to the current stable version and fixes a lot of features that
were broken, at least with the current version and our configuration.

Quite a lot of sweat and tears has gone into testing nearly all features and
reading/patching the Gitlab source as we're about to deploy gitlab for our
whole company.

Things to note:

 * The gitlab config is now written as a nix attribute set and will be
   converted to JSON. Gitlab uses YAML but JSON is a subset of YAML.
   The `extraConfig` opition is also an attribute set that will be merged
   with the default config. This way *all* Gitlab options are supported.

 * Some paths like uploads and configs are hardcoded in rails  (at least
   after my study of the Gitlab source). This is why they are linked from
   the Gitlab root to /run/gitlab and then linked to the  configurable
   `statePath`.

 * Backup & restore should work out of the box from another Gitlab instance.

 * gitlab-git-http-server has been replaced by gitlab-workhorse upstream.
   Push & pull over HTTPS works perfectly. Communication to gitlab is done
   over unix sockets. An HTTP server is required to proxy requests to
   gitlab-workhorse over another unix socket at
   `/run/gitlab/gitlab-workhorse.socket`.

 * The user & group running gitlab are now configurable. These can even be
   changed for live instances.

 * The initial email address & password of the root user can be configured.

Fixes #8598.

pkgs/applications/version-management/gitlab/default.nix

@@ -1,7 +1,10 @@
-{ stdenv, lib, bundler, fetchgit, bundlerEnv, defaultGemConfig, libiconv, ruby
+{ stdenv, lib, bundler, fetchFromGitHub, bundlerEnv, defaultGemConfig, libiconv, ruby
 , tzdata, git, nodejs, procps
 }:
 
+/* When updating the Gemfile add `gem "activerecord-nulldb-adapter"`
+   to allow building the assets without a database */
+
 let
   env = bundlerEnv {
     name = "gitlab";
@@ -21,19 +24,23 @@ in
 
 stdenv.mkDerivation rec {
   name = "gitlab-${version}";
-  version = "8.0.5";
+  version = "8.5.0";
+
   buildInputs = [ ruby bundler tzdata git nodejs procps ];
-  src = fetchgit {
-    url = "https://github.com/gitlabhq/gitlabhq.git";
-    rev = "2866c501b5a5abb69d101cc07261a1d684b4bd4c";
-    fetchSubmodules = false;
-    sha256 = "edc6bedd5e79940189355d8cb343d20b0781b69fcef56ccae5906fa5e81ed521";
+
+  src = fetchFromGitHub {
+    owner = "gitlabhq";
+    repo = "gitlabhq";
+    rev = "v${version}";
+    sha256 = "1rhl906xnvpxkw3ngwfzi80cl3daihx5vizy04b9b39adyd3i5hl";
   };
 
   patches = [
     ./remove-hardcoded-locations.patch
     ./disable-dump-schema-after-migration.patch
+    ./nulladapter.patch
   ];
+
   postPatch = ''
     # For reasons I don't understand "bundle exec" ignores the
     # RAILS_ENV causing tests to be executed that fail because we're
@@ -41,7 +48,6 @@ stdenv.mkDerivation rec {
     # tests works though.:
     rm lib/tasks/test.rake
 
-    mv config/gitlab.yml.example config/gitlab.yml
     rm config/initializers/gitlab_shell_secret_token.rb
 
     substituteInPlace app/controllers/admin/background_jobs_controller.rb \
@@ -50,7 +56,7 @@ stdenv.mkDerivation rec {
     # required for some gems:
     cat > config/database.yml <<EOF
       production:
-        adapter: postgresql
+        adapter: <%= ENV["GITLAB_DATABASE_ADAPTER"] || sqlite %>
         database: gitlab
         host: <%= ENV["GITLAB_DATABASE_HOST"] || "127.0.0.1" %>
         password: <%= ENV["GITLAB_DATABASE_PASSWORD"] || "blerg" %>
@@ -58,14 +64,22 @@ stdenv.mkDerivation rec {
         encoding: utf8
     EOF
   '';
+
   buildPhase = ''
     export GEM_HOME=${env}/${ruby.gemPath}
-    bundle exec rake assets:precompile RAILS_ENV=production
+    mv config/gitlab.yml.example config/gitlab.yml
+    GITLAB_DATABASE_ADAPTER=nulldb bundle exec rake assets:precompile RAILS_ENV=production
+    mv config/gitlab.yml config/gitlab.yml.example
+    mv config config.dist
   '';
+
   installPhase = ''
     mkdir -p $out/share
     cp -r . $out/share/gitlab
+    ln -sf /run/gitlab/uploads $out/share/gitlab/public/uploads
+    ln -sf /run/gitlab/config $out/share/gitlab/config
   '';
+
   passthru = {
     inherit env;
     inherit ruby;