1 files changed, 95 insertions, 0 deletions
diff --git a/lib/gitlab/git/repository_mirroring.rb b/lib/gitlab/git/repository_mirroring.rb
new file mode 100644
index 00000000000..637e7a0659c
--- /dev/null
+++ b/lib/gitlab/git/repository_mirroring.rb
@@ -0,0 +1,95 @@
+module Gitlab
+  module Git
+    module RepositoryMirroring
+      IMPORT_HEAD_REFS = '+refs/heads/*:refs/heads/*'.freeze
+      IMPORT_TAG_REFS = '+refs/tags/*:refs/tags/*'.freeze
+      MIRROR_REMOTE = 'mirror'.freeze
+
+      RemoteError = Class.new(StandardError)
+
+      def set_remote_as_mirror(remote_name)
+        # This is used to define repository as equivalent as "git clone --mirror"
+        rugged.config["remote.#{remote_name}.fetch"] = 'refs/*:refs/*'
+        rugged.config["remote.#{remote_name}.mirror"] = true
+        rugged.config["remote.#{remote_name}.prune"] = true
+      end
+
+      def set_import_remote_as_mirror(remote_name)
+        # Add first fetch with Rugged so it does not create its own.
+        rugged.config["remote.#{remote_name}.fetch"] = IMPORT_HEAD_REFS
+
+        add_remote_fetch_config(remote_name, IMPORT_TAG_REFS)
+
+        rugged.config["remote.#{remote_name}.mirror"] = true
+        rugged.config["remote.#{remote_name}.prune"] = true
+      end
+
+      def add_remote_fetch_config(remote_name, refspec)
+        run_git(%W[config --add remote.#{remote_name}.fetch #{refspec}])
+      end
+
+      def fetch_mirror(url)
+        add_remote(MIRROR_REMOTE, url)
+        set_remote_as_mirror(MIRROR_REMOTE)
+        fetch(MIRROR_REMOTE)
+        remove_remote(MIRROR_REMOTE)
+      end
+
+      def remote_tags(remote)
+        # Each line has this format: "dc872e9fa6963f8f03da6c8f6f264d0845d6b092\trefs/tags/v1.10.0\n"
+        # We want to convert it to: [{ 'v1.10.0' => 'dc872e9fa6963f8f03da6c8f6f264d0845d6b092' }, ...]
+        list_remote_tags(remote).map do |line|
+          target, path = line.strip.split("\t")
+
+          # When the remote repo does not have tags.
+          if target.nil? || path.nil?
+            Rails.logger.info "Empty or invalid list of tags for remote: #{remote}. Output: #{output}"
+            return []
+          end
+
+          name = path.split('/', 3).last
+          # We're only interested in tag references
+          # See: http://stackoverflow.com/questions/15472107/when-listing-git-ls-remote-why-theres-after-the-tag-name
+          next if name =~ /\^\{\}\Z/
+
+          target_commit = Gitlab::Git::Commit.find(self, target)
+          Gitlab::Git::Tag.new(self, name, target, target_commit)
+        end.compact
+      end
+
+      def remote_branches(remote_name)
+        branches = []
+
+        rugged.references.each("refs/remotes/#{remote_name}/*").map do |ref|
+          name = ref.name.sub(/\Arefs\/remotes\/#{remote_name}\//, '')
+
+          begin
+            target_commit = Gitlab::Git::Commit.find(self, ref.target)
+            branches << Gitlab::Git::Branch.new(self, name, ref.target, target_commit)
+          rescue Rugged::ReferenceError
+            # Omit invalid branch
+          end
+        end
+
+        branches
+      end
+
+      private
+
+      def list_remote_tags(remote)
+        tag_list, exit_code, error = nil
+        cmd = %W(#{Gitlab.config.git.bin_path} --git-dir=#{full_path} ls-remote --tags #{remote})
+
+        Open3.popen3(*cmd) do |stdin, stdout, stderr, wait_thr|
+          tag_list  = stdout.read
+          error     = stderr.read
+          exit_code = wait_thr.value.exitstatus
+        end
+
+        raise RemoteError, error unless exit_code.zero?
+
+        tag_list.split('\n')
+      end
+    end
+  end
+end