Merge branch '2774-update_databases-assumes-a-populated-databases-json' into 'master'

Resolve "update_databases assumes a populated databases.json"

Closes #2774

See merge request !1924

CHANGELOG.md

@@ -27,6 +27,7 @@ omnibus-gitlab repository.
 - Add more options to repmgr.conf template
 - Update pgbouncer to use one style of logging 
 - Set bootstrap_expect to default to 3 for consul servers
+- Fix bug where pgb-notify would fail when databases.json was empty
 9.5.4

files/gitlab-ctl-commands-ee/lib/pgbouncer.rb

+require 'chef/mixins'
 require 'erb'
 # For testing purposes, if the first path cannot be found load the second
@@ -9,7 +10,7 @@ end
 module Pgbouncer
   class Databases
-    attr_accessor :install_path, :databases, :options, :ini_file, :json_file, :template_file, :attributes, :userinfo
+    attr_accessor :install_path, :databases, :options, :ini_file, :json_file, :template_file, :attributes, :userinfo, :database
     attr_reader :data_path
     def initialize(options, install_path, base_data_path)
@@ -20,12 +21,22 @@ module Pgbouncer
       @ini_file = options['databases_ini'] || attributes['gitlab']['pgbouncer']['databases_ini']
       @json_file = options['databases_json'] || attributes['gitlab']['pgbouncer']['databases_json']
       @template_file = "#{@install_path}/embedded/cookbooks/gitlab-ee/templates/default/databases.ini.erb"
+      @database = if attributes.key?('gitlab')
+                    attributes['gitlab']['gitlab-rails']['db_database']
+                  else
+                    'gitlabhq_production'
+                  end
       @databases = update_databases(JSON.parse(File.read(@json_file)))
       @userinfo = GitlabCtl::Util.userinfo(options['host_user']) if options['host_user']
     end
     def update_databases(original)
-      updated = {}
+      if original.empty?
+        original = {
+          database => {}
+        }
+      end
+      updated = Chef::Mixin::DeepMerge.merge(updated, original)
       original.each do |db, settings|
         updated[db] = ''
         settings['host'] = options['newhost'] if options['newhost']

spec/gitlab-ctl-commands-ee/lib/pgbouncer_spec.rb

@@ -9,6 +9,9 @@ describe Pgbouncer::Databases do
     {
       normal: {
         gitlab: {
+          'gitlab-rails': {
+            db_database: 'fake_database'
+          },
           pgbouncer: {
             databases_ini: '/fakedata/pgbouncer/databases.ini',
             databases_json: '/fakedata/pgbouncer/databases.json'
@@ -81,4 +84,17 @@ describe Pgbouncer::Databases do
       )
     end
   end
+
+  context 'with empty databases.json' do
+    before do
+      allow(File).to receive(:read).with('/fakedata/pgbouncer/databases.json').and_return({}.to_s)
+      @obj = Pgbouncer::Databases.new({}, '/fakeinstall', '/fakedata')
+    end
+
+    it 'should generate an databases.ini with sane defaults' do
+      expect(@obj.render).to eq(
+        "[databases]\n\nfake_database = \n\n"
+      )
+    end
+  end
 end