Merge branch 'ci-commit-as-pipeline' into 'master'

Ci::Commit becomes a Pipeline object

1. Ci::Commit receives context: ref, :tag.
1. One Ci::Commit describes a one Pipeline
1. Pipeline is created from `.gitlab-ci.yml`
1. Pipeline is a ordered group of builds
1. We test MR against Pipeline
1. Pipelines have a separate view (https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3703)
1. Pipeline can be triggered from UI (https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3703)
1. Later we change `Trigger -> TriggerRequest -> Build` to `Trigger -> Pipeline` (future)
1. We add a Pipeline Hook that will be triggered on Pipeline status change  (future)
1. We extend notifications to use `Pipeline Hook` to send summary on pipeline changes (future)

After merging that I'll prepare a separate MR that will unify naming, database columns, table names:
```
Ci::Commit -> Pipeline
Ci::Build -> Build
CommitStatus -> Job
GenericCommitStatus -> ExternalJob

ci_commits -> pipelines
ci_builds -> jobs
```

This MR implements first 5 points.

This is made to solve this issue https://gitlab.com/gitlab-org/gitlab-ce/issues/14149.

See merge request !3653

3 files changed, 62 insertions, 0 deletions

diff --git a/db/migrate/20160412173416_add_fields_to_ci_commit.rb b/db/migrate/20160412173416_add_fields_to_ci_commit.rb
new file mode 100644
index 00000000000..125956a3ddd
--- /dev/null
+++ b/db/migrate/20160412173416_add_fields_to_ci_commit.rb
@@ -0,0 +1,8 @@
+class AddFieldsToCiCommit < ActiveRecord::Migration
+  def change
+    add_column :ci_commits, :status, :string
+    add_column :ci_commits, :started_at, :timestamp
+    add_column :ci_commits, :finished_at, :timestamp
+    add_column :ci_commits, :duration, :integer
+  end
+end
diff --git a/db/migrate/20160412173417_update_ci_commit.rb b/db/migrate/20160412173417_update_ci_commit.rb
new file mode 100644
index 00000000000..fd92444dbac
--- /dev/null
+++ b/db/migrate/20160412173417_update_ci_commit.rb
@@ -0,0 +1,35 @@
+class UpdateCiCommit < ActiveRecord::Migration
+  # This migration can be run online, but needs to be executed for the second time after restarting Unicorn workers
+  # Otherwise Offline migration should be used.
+  def change
+    execute("UPDATE ci_commits SET status=#{status}, ref=#{ref}, tag=#{tag} WHERE status IS NULL")
+  end
+
+  private
+
+  def status
+    builds = '(SELECT COUNT(*) FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id)'
+    success = "(SELECT COUNT(*) FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id AND status='success')"
+    ignored = "(SELECT COUNT(*) FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id AND (status='failed' OR status='canceled') AND allow_failure)"
+    pending = "(SELECT COUNT(*) FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id AND status='pending')"
+    running = "(SELECT COUNT(*) FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id AND status='running')"
+    canceled = "(SELECT COUNT(*) FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id AND status='canceled')"
+
+    "(CASE
+      WHEN #{builds}=0 THEN 'skipped'
+      WHEN #{builds}=#{success}+#{ignored} THEN 'success'
+      WHEN #{builds}=#{pending} THEN 'pending'
+      WHEN #{builds}=#{canceled} THEN 'canceled'
+      WHEN #{running}+#{pending}>0 THEN 'running'
+      ELSE 'failed'
+    END)"
+  end
+
+  def ref
+    '(SELECT ref FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id ORDER BY id DESC LIMIT 1)'
+  end
+
+  def tag
+    '(SELECT tag FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id ORDER BY id DESC LIMIT 1)'
+  end
+end
diff --git a/db/migrate/20160412173418_add_ci_commit_indexes.rb b/db/migrate/20160412173418_add_ci_commit_indexes.rb
new file mode 100644
index 00000000000..603d4a41610
--- /dev/null
+++ b/db/migrate/20160412173418_add_ci_commit_indexes.rb
@@ -0,0 +1,19 @@
+class AddCiCommitIndexes < ActiveRecord::Migration
+  disable_ddl_transaction!
+
+  def change
+    add_index :ci_commits, [:gl_project_id, :sha], index_options
+    add_index :ci_commits, [:gl_project_id, :status], index_options
+    add_index :ci_commits, [:status], index_options
+  end
+
+  private
+
+  def index_options
+    if Gitlab::Database.postgresql?
+      { algorithm: :concurrently }
+    else
+      { }
+    end
+  end
+end