Implement commit transaction with pre-receive and post-receive hooks for web editor

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

6 files changed, 117 insertions, 8 deletions

diff --git a/app/services/commit_service.rb b/app/services/commit_service.rb
new file mode 100644
index 00000000000..a5603f26692
--- /dev/null
+++ b/app/services/commit_service.rb
@@ -0,0 +1,37 @@
+require 'securerandom'
+
+class CommitService
+  def self.transaction(project, current_user, ref)
+    repository = project.repository
+    path_to_repo = repository.path_to_repo
+
+    # Create temporary ref
+    random_string = SecureRandom.hex
+    tmp_ref = "refs/tmp/#{random_string}/head"
+    target = repository.find_branch(ref).target
+    repository.rugged.references.create(tmp_ref, target)
+
+    # Make commit in tmp ref
+    sha = yield(tmp_ref)
+
+    unless sha
+      raise 'Failed to create commit'
+    end
+
+    # Run GitLab pre-receive hook
+    status = PreCommitService.new(project, current_user).execute(sha, ref)
+
+    if status
+      # Update head
+      repository.rugged.references.update(Gitlab::Git::BRANCH_REF_PREFIX + ref, sha)
+
+      # Run GitLab post receive hook
+      PostCommitService.new(project, current_user).execute(sha, ref)
+    else
+      # Remove tmp ref and return error to user
+      repository.rugged.references.delete(tmp_ref)
+
+      raise 'Commit was rejected by pre-reveive hook'
+    end
+  end
+end
diff --git a/app/services/files/base_service.rb b/app/services/files/base_service.rb
index d7b40ee8906..1f7b92e222b 100644
--- a/app/services/files/base_service.rb
+++ b/app/services/files/base_service.rb
@@ -22,7 +22,6 @@ module Files
       end
 
       if sha = commit
-        after_commit(sha, @target_branch)
         success
       else
         error("Something went wrong. Your changes were not committed")
@@ -33,10 +32,6 @@ module Files
 
     private
 
-    def after_commit(sha, branch)
-      PostCommitService.new(project, current_user).execute(sha, branch)
-    end
-
     def current_branch
       @current_branch ||= params[:current_branch]
     end
diff --git a/app/services/files/create_service.rb b/app/services/files/create_service.rb
index 91d715b2d63..3e00864f00d 100644
--- a/app/services/files/create_service.rb
+++ b/app/services/files/create_service.rb
@@ -3,7 +3,9 @@ require_relative "base_service"
 module Files
   class CreateService < Files::BaseService
     def commit
-      repository.commit_file(current_user, @file_path, @file_content, @commit_message, @target_branch)
+      CommitService.transaction(project, current_user, @target_branch)  do |tmp_ref|
+        repository.commit_file(current_user, @file_path, @file_content, @commit_message, tmp_ref)
+      end
     end
 
     def validate
diff --git a/app/services/files/delete_service.rb b/app/services/files/delete_service.rb
index 27c881c3430..d61ca31cf9d 100644
--- a/app/services/files/delete_service.rb
+++ b/app/services/files/delete_service.rb
@@ -3,7 +3,9 @@ require_relative "base_service"
 module Files
   class DeleteService < Files::BaseService
     def commit
-      repository.remove_file(current_user, @file_path, @commit_message, @target_branch)
+      CommitService.transaction(project, current_user, @target_branch)  do |tmp_ref|
+        repository.remove_file(current_user, @file_path, @commit_message, tmp_ref)
+      end
     end
   end
 end
diff --git a/app/services/files/update_service.rb b/app/services/files/update_service.rb
index a20903c6f02..69212b36996 100644
--- a/app/services/files/update_service.rb
+++ b/app/services/files/update_service.rb
@@ -3,7 +3,9 @@ require_relative "base_service"
 module Files
   class UpdateService < Files::BaseService
     def commit
-      repository.commit_file(current_user, @file_path, @file_content, @commit_message, @target_branch)
+      CommitService.transaction(project, current_user, @target_branch)  do |tmp_ref|
+        repository.commit_file(current_user, @file_path, @file_content, @commit_message, tmp_ref)
+      end
     end
   end
 end
diff --git a/app/services/pre_commit_service.rb b/app/services/pre_commit_service.rb
new file mode 100644
index 00000000000..ed8331ddce4
--- /dev/null
+++ b/app/services/pre_commit_service.rb
@@ -0,0 +1,71 @@
+class PreCommitService < BaseService
+  include Gitlab::Popen
+
+  attr_reader :changes, :repo_path
+
+  def execute(sha, branch)
+    commit = repository.commit(sha)
+    full_ref = Gitlab::Git::BRANCH_REF_PREFIX + branch
+    old_sha = commit.parent_id || Gitlab::Git::BLANK_SHA
+    @changes = "#{old_sha} #{sha} #{full_ref}"
+    @repo_path = repository.path_to_repo
+
+    pre_receive
+  end
+
+  private
+
+  def pre_receive
+    hook = hook_file('pre-receive', repo_path)
+    return true if hook.nil?
+    call_receive_hook(hook)
+  end
+
+  def call_receive_hook(hook)
+    # function  will return true if succesful
+    exit_status = false
+
+    vars = {
+      'GL_ID' => Gitlab::ShellEnv.gl_id(current_user),
+      'PWD' => repo_path
+    }
+
+    options = {
+      chdir: repo_path
+    }
+
+    # we combine both stdout and stderr as we don't know what stream
+    # will be used by the custom hook
+    Open3.popen2e(vars, hook, options) do |stdin, stdout_stderr, wait_thr|
+      exit_status = true
+      stdin.sync = true
+
+      # in git, pre- and post- receive hooks may just exit without
+      # reading stdin. We catch the exception to avoid a broken pipe
+      # warning
+      begin
+        # inject all the changes as stdin to the hook
+        changes.lines do |line|
+          stdin.puts line
+        end
+      rescue Errno::EPIPE
+      end
+
+      # need to close stdin before reading stdout
+      stdin.close
+
+      # only output stdut_stderr if scripts doesn't return 0
+      unless wait_thr.value == 0
+        exit_status = false
+      end
+    end
+
+    exit_status
+  end
+
+  def hook_file(hook_type, repo_path)
+    hook_path = File.join(repo_path.strip, 'hooks')
+    hook_file = "#{hook_path}/#{hook_type}"
+    hook_file if File.exist?(hook_file)
+  end
+end