Added ability to disable a previously enabled consul service

This is done following the same pattern of an `enable` and `disable`
recipe. Unless a service is explicitly enabled, we consider it to be disabled.

Test coverage for existing consul recipe was split into the corresponding
spec files at the correct folder location.

changelogs/unreleased/5579-consul-should-allow-to-disable-monitored-services.yml

+---
+title: Added ability to disable a previously enabled consul service
+merge_request: 4502
+author:
+type: changed

files/gitlab-cookbooks/consul/libraries/consul_helper.rb

 class ConsulHelper
   attr_reader :node, :default_configuration, :default_server_configuration
+  # List of existing services that we provide configuration for consul monitoring
+  #
+  # When adding a new service to consul, add to the constant below and make sure you
+  # provide an `enable_service_#{service_name}` and `disable_service_#{service_name}` recipe
+  SERVICES = %w(postgresql).freeze
+
   def initialize(node)
     @node = node
     @default_configuration = {
@@ -68,4 +74,20 @@ class ConsulHelper
     cfg
   end
+
+  # Return a list of enabled services
+  #
+  # @return [Array] list of enabled services
+  def enabled_services
+    node['consul']['services']
+  end
+
+  # Return a list of disabled services
+  #
+  # The list is generated by intersecting the existing services with the list of enabled
+  #
+  # @return [Array] list of services that are disabled
+  def disabled_services
+    SERVICES - node['consul']['services']
+  end
 end

files/gitlab-cookbooks/consul/recipes/configure_services.rb

+#
+# Copyright:: Copyright (c) 2020 GitLab Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+consul_helper = ConsulHelper.new(node)
+
+consul_helper.enabled_services.each do |service|
+  include_recipe "consul::enable_service_#{service}"
+end
+
+consul_helper.disabled_services.each do |service|
+  include_recipe "consul::disable_service_#{service}"
+end

files/gitlab-cookbooks/consul/recipes/disable_service_postgresql.rb

+#
+# Copyright:: Copyright (c) 2020 GitLab Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+file "#{node['consul']['config_dir']}/postgresql_service.json" do
+  action :delete
+
+  notifies :run, 'execute[reload consul]', :delayed
+end

files/gitlab-cookbooks/consul/recipes/enable.rb

@@ -61,9 +61,7 @@ file "#{node['consul']['dir']}/config.json" do
   notifies :run, 'execute[reload consul]'
 end
-node['consul']['services'].each do |service|
-  include_recipe "consul::service_#{service}"
-end
+include_recipe 'consul::configure_services'
 include_recipe 'consul::watchers'

spec/chef/consul/recipes/configure_services_spec.rb

+require 'chef_helper'
+
+RSpec.describe 'consul::configure_services' do
+  let(:chef_run) { ChefSpec::SoloRunner.new(step_into: %w(runit_service)).converge('gitlab-ee::default') }
+
+  before do
+    allow(Gitlab).to receive(:[]).and_call_original
+  end
+
+  describe 'enabling services' do
+    before do
+      stub_gitlab_rb(
+        consul: {
+          enable: true,
+          services: %w(postgresql)
+        }
+      )
+    end
+
+    it 'includes the enable_service recipe for the corresponding service' do
+      expect(chef_run).to include_recipe('consul::enable_service_postgresql')
+    end
+  end
+
+  describe 'disabling services' do
+    before do
+      stub_gitlab_rb(
+        consul: {
+          enable: true,
+          services: []
+        }
+      )
+    end
+
+    it 'includes the disable_service for all known services' do
+      expect(chef_run).to include_recipe('consul::disable_service_postgresql')
+    end
+  end
+end

spec/chef/gitlab-ee/recipes/consul_spec.rb → spec/chef/consul/recipes/consul_spec.rb

@@ -24,8 +24,7 @@ RSpec.describe 'consul' do
         consul: {
           enable: true,
           config_dir: '/fake/config.d',
-          data_dir: '/fake/data',
-          services: %w(postgresql)
+          data_dir: '/fake/data'
         }
       )
     end
@@ -41,8 +40,8 @@ RSpec.describe 'consul' do
         expect(chef_run).to create_account('Consul user and group').with(username: 'gitlab-consul', groupname: 'gitlab-consul')
       end
-      it 'includes the postgresql_service recipe' do
-        expect(chef_run).to include_recipe('consul::service_postgresql')
+      it 'includes the configure_services recipe' do
+        expect(chef_run).to include_recipe('consul::configure_services')
       end
       it 'only enables the agent by default' do
@@ -137,124 +136,4 @@ RSpec.describe 'consul' do
       end
     end
   end
-
-  describe 'consul::service_postgresql' do
-    let(:chef_run) { ChefSpec::SoloRunner.new(step_into: %w(runit_service)).converge('gitlab-ee::default') }
-
-    before do
-      allow(Gitlab).to receive(:[]).and_call_original
-    end
-
-    context 'default' do
-      before do
-        stub_gitlab_rb(
-          consul: {
-            enable: true,
-            services: %w(postgresql)
-          }
-        )
-      end
-
-      it 'renders the service configuration file' do
-        rendered = {
-          'service' => {
-            'name' => 'postgresql',
-            'address' => '',
-            'port' => 5432,
-            'check' => {
-              'id' => 'service:postgresql',
-              'args' => ["/opt/gitlab/bin/gitlab-ctl", "repmgr-check-master"],
-              'interval' => '10s',
-              'status' => 'failing'
-            }
-          },
-          'watches' => [
-            {
-              'type' => 'keyprefix',
-              'prefix' => 'gitlab/ha/postgresql/failed_masters/',
-              'args' => ["/opt/gitlab/bin/gitlab-ctl", "consul", "watchers", "handle-failed-master"]
-            }
-          ]
-        }
-        expect(chef_run).to render_file('/var/opt/gitlab/consul/config.d/postgresql_service.json').with_content { |content|
-          expect(JSON.parse(content)).to eq(rendered)
-        }
-      end
-    end
-
-    context 'when patroni is enabled' do
-      before do
-        stub_gitlab_rb(
-          patroni: {
-            enable: true
-          },
-          consul: {
-            enable: true,
-            services: %w(postgresql)
-          }
-        )
-      end
-
-      it 'renders the service configuration file' do
-        rendered = {
-          'service' => {
-            'name' => 'postgresql',
-            'address' => '',
-            'port' => 5432,
-            'check' => {
-              'id' => 'service:postgresql',
-              'args' => ['/opt/gitlab/bin/gitlab-ctl', 'patroni', 'check-leader'],
-              'interval' => '10s',
-              'status' => 'failing'
-            }
-          }
-        }
-        expect(chef_run).to render_file('/var/opt/gitlab/consul/config.d/postgresql_service.json').with_content { |content|
-          expect(JSON.parse(content)).to eq(rendered)
-        }
-      end
-    end
-  end
-
-  describe 'consul::watchers' do
-    let(:chef_run) { ChefSpec::SoloRunner.converge('gitlab-ee::default') }
-    let(:watcher_conf) { '/var/opt/gitlab/consul/config.d/watcher_postgresql.json' }
-    let(:watcher_check) { '/var/opt/gitlab/consul/scripts/failover_pgbouncer' }
-
-    before do
-      allow(Gitlab).to receive(:[]).and_call_original
-      stub_gitlab_rb(
-        consul: {
-          enable: true,
-          watchers: %w(
-            postgresql
-          )
-        }
-      )
-    end
-
-    it 'includes the watcher recipe' do
-      expect(chef_run).to include_recipe('consul::watchers')
-    end
-
-    it 'creates the watcher config file' do
-      rendered = {
-        'watches' => [
-          {
-            'type' => 'service',
-            'service' => 'postgresql',
-            'args' => [watcher_check]
-          }
-        ]
-      }
-
-      expect(chef_run).to render_file(watcher_conf).with_content { |content|
-        expect(JSON.parse(content)).to eq(rendered)
-      }
-    end
-
-    it 'creates the watcher handler file' do
-      expect(chef_run).to render_file(watcher_check)
-    end
-  end
 end

spec/chef/consul/recipes/consul_watcher_spec.rb

+require 'chef_helper'
+
+RSpec.describe 'consul::watchers' do
+  let(:chef_run) { ChefSpec::SoloRunner.converge('gitlab-ee::default') }
+  let(:watcher_conf) { '/var/opt/gitlab/consul/config.d/watcher_postgresql.json' }
+  let(:watcher_check) { '/var/opt/gitlab/consul/scripts/failover_pgbouncer' }
+
+  before do
+    allow(Gitlab).to receive(:[]).and_call_original
+
+    stub_gitlab_rb(
+      consul: {
+        enable: true,
+        watchers: %w(postgresql)
+      }
+    )
+  end
+
+  it 'includes the watcher recipe' do
+    expect(chef_run).to include_recipe('consul::watchers')
+  end
+
+  it 'creates the watcher config file' do
+    rendered = {
+      'watches' => [
+        {
+          'type' => 'service',
+          'service' => 'postgresql',
+          'args' => [watcher_check]
+        }
+      ]
+    }
+
+    expect(chef_run).to render_file(watcher_conf).with_content { |content|
+      expect(JSON.parse(content)).to eq(rendered)
+    }
+  end
+
+  it 'creates the watcher handler file' do
+    expect(chef_run).to render_file(watcher_check)
+  end
+end

spec/chef/consul/recipes/disable_service_postgresql_spec.rb

+require 'chef_helper'
+
+RSpec.describe 'consul::disable_service_postgresql' do
+  let(:chef_run) { ChefSpec::SoloRunner.new(step_into: %w(runit_service)).converge('gitlab-ee::default', 'consul::disable_service_postgresql') }
+
+  before do
+    allow(Gitlab).to receive(:[]).and_call_original
+  end
+
+  context 'default' do
+    before do
+      stub_gitlab_rb(
+        consul: {
+          enable: true,
+          services: []
+        }
+      )
+    end
+
+    it 'deletes the service configuration file' do
+      expect(chef_run).to delete_file('/var/opt/gitlab/consul/config.d/postgresql_service.json')
+    end
+  end
+end

spec/chef/consul/recipes/enable_service_postgresq_spec.rb

+require 'chef_helper'
+
+RSpec.describe 'consul::enable_service_postgresql' do
+  let(:chef_run) { ChefSpec::SoloRunner.new(step_into: %w(runit_service)).converge('gitlab-ee::default') }
+
+  before do
+    allow(Gitlab).to receive(:[]).and_call_original
+  end
+
+  context 'default' do
+    before do
+      stub_gitlab_rb(
+        consul: {
+          enable: true,
+          services: %w(postgresql)
+        }
+      )
+    end
+
+    it 'renders the service configuration file' do
+      rendered = {
+        'service' => {
+          'name' => 'postgresql',
+          'address' => '',
+          'port' => 5432,
+          'check' => {
+            'id' => 'service:postgresql',
+            'args' => ["/opt/gitlab/bin/gitlab-ctl", "repmgr-check-master"],
+            'interval' => '10s',
+            'status' => 'failing'
+          }
+        },
+        'watches' => [
+          {
+            'type' => 'keyprefix',
+            'prefix' => 'gitlab/ha/postgresql/failed_masters/',
+            'args' => ["/opt/gitlab/bin/gitlab-ctl", "consul", "watchers", "handle-failed-master"]
+          }
+        ]
+      }
+      expect(chef_run).to render_file('/var/opt/gitlab/consul/config.d/postgresql_service.json').with_content { |content|
+        expect(JSON.parse(content)).to eq(rendered)
+      }
+    end
+  end
+
+  context 'when patroni is enabled' do
+    before do
+      stub_gitlab_rb(
+        patroni: {
+          enable: true
+        },
+        consul: {
+          enable: true,
+          services: %w(postgresql)
+        }
+      )
+    end
+
+    it 'renders the service configuration file' do
+      rendered = {
+        'service' => {
+          'name' => 'postgresql',
+          'address' => '',
+          'port' => 5432,
+          'check' => {
+            'id' => 'service:postgresql',
+            'args' => ['/opt/gitlab/bin/gitlab-ctl', 'patroni', 'check-leader'],
+            'interval' => '10s',
+            'status' => 'failing'
+          }
+        }
+      }
+      expect(chef_run).to render_file('/var/opt/gitlab/consul/config.d/postgresql_service.json').with_content { |content|
+        expect(JSON.parse(content)).to eq(rendered)
+      }
+    end
+  end
+end