Merge migrations and fix schema.rb + add required fields to prometheus metrics

app/models/prometheus_metric.rb

@@ -4,10 +4,18 @@ class PrometheusMetric < ActiveRecord::Base
 
   validates :title, presence: true
   validates :query, presence: true
+  validates :group, presence: true
+
+  GROUP_NAMES = {
+    business_metrics: 'Business metrics',
+    response: 'Response metrics',
+    system: 'System metrics'
+  }.freeze
 
   def self.to_grouped_query_metrics
-    self.all.group_by(&:group).map do |name, metrics|
-      [name, metrics.map(&:to_query_metric)]
+    self.all.group_by(&:group).map do |group, metrics|
+      group ||= :business
+      [GROUP_NAMES[group], metrics.map(&:to_query_metric)]
     end
   end
 

db/migrate/20171214160629_create_prometheus_metrics.rb → db/migrate/20180101160629_create_prometheus_metrics.rb

@@ -2,12 +2,13 @@ class CreatePrometheusMetrics < ActiveRecord::Migration
   def change
     create_table :prometheus_metrics do |t|
       t.references :project, index: true, foreign_key: true
-      t.string :title
-      t.string :query
+      t.string :title, null: false
+      t.string :query, null: false
       t.string :y_label
       t.string :unit
       t.string :legend
-
+      t.integer :group, null: false
+      t.index :group
       t.timestamps null: false
     end
   end

db/migrate/20180104215427_add_group_to_prometheus_metrics.rb

-# See http://doc.gitlab.com/ce/development/migration_style_guide.html
-# for more information on how to write migrations for GitLab.
-
-class AddGroupToPrometheusMetrics < ActiveRecord::Migration
-  include Gitlab::Database::MigrationHelpers
-  DOWNTIME = false
-
-  def change
-    add_column :prometheus_metrics, :group, :integer
-    add_index :prometheus_metrics, :group
-  end
-end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20180104215427) do
+ActiveRecord::Schema.define(version: 20180101160629) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -1895,11 +1895,12 @@ ActiveRecord::Schema.define(version: 20180104215427) do
 
   create_table "prometheus_metrics", force: :cascade do |t|
     t.integer "project_id"
-    t.string "title"
-    t.string "query"
+    t.string "title", null: false
+    t.string "query", null: false
     t.string "y_label"
     t.string "unit"
     t.string "legend"
+    t.integer "group", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
   end