Added Sidekiq setup documentation

doc/administration/high_availability/README.md

@@ -110,7 +110,7 @@ them.
 | [PgBouncer](../../development/architecture.md#pgbouncer)                                                            | Database Pool Manager                                               | [PgBouncer HA configuration](pgbouncer.md) **(PREMIUM ONLY)** |
 | [Redis](../../development/architecture.md#redis)[^3] with Redis Sentinel                                            | Key/Value store for shared data with HA watcher service             | [Redis HA configuration](redis.md)                            |
 | [Gitaly](../../development/architecture.md#gitaly)[^2] [^5] [^7]                                                    | Recommended high-level storage for Git repository data              | [Gitaly HA configuration](gitaly.md)                          |
-| [Sidekiq](../../development/architecture.md#sidekiq)                                                                | Asynchronous/Background jobs                                        |                                                               |
+| [Sidekiq](../../development/architecture.md#sidekiq)                                                                | Asynchronous/Background jobs                                        | [Sidekiq configuration](sidekiq.md)                           |
 | [GitLab application nodes](../../development/architecture.md#unicorn)[^1]                                           | (Unicorn / Puma, Workhorse) - Web-requests (UI, API, Git over HTTP) | [GitLab app HA/scaling configuration](gitlab.md)              |
 | [Prometheus](../../development/architecture.md#prometheus) and [Grafana](../../development/architecture.md#grafana) | GitLab environment monitoring                                       | [Monitoring node for scaling/HA](monitoring_node.md)          |
 

doc/administration/high_availability/sidekiq.md

+---
+type: reference
+---
+
+# Configuring Sidekiq
+
+This section discusses how to configure an external Sidekiq instance.
+
+Sidekiq requires connection to the Redis, PostgreSQL and Gitaly instance.
+To configure the Sidekiq node:
+
+1. SSH into the Sidekiq server.
+
+1. [Download/install](https://about.gitlab.com/install/) the Omnibus GitLab package
+you want using steps 1 and 2 from the GitLab downloads page.
+**Do not complete any other steps on the download page.**
+
+1. Open `/etc/gitlab/gitlab.rb` with your editor.
+
+1. Generate the Sidekiq configuration:
+
+   ```ruby
+   sidekiq['listen_address'] = "10.10.1.48"
+
+   ## Optional: Enable extra Sidekiq processes
+   sidekiq_cluster['enable'] = true
+   sidekiq_cluster['enable'] = true
+     "elastic_indexer"
+   ]
+   ```
+
+1. Setup Sidekiq's connection to Redis:
+
+   ```ruby
+   ## Must be the same in every sentinel node
+   redis['master_name'] = 'gitlab-redis'
+
+   ## The same password for Redis authentication you set up for the master node.
+   redis['master_password'] = 'YOUR_PASSOWORD'
+
+   ## A list of sentinels with `host` and `port`
+   gitlab_rails['redis_sentinels'] = [
+       {'host' => '10.10.1.34', 'port' => 26379},
+       {'host' => '10.10.1.35', 'port' => 26379},
+       {'host' => '10.10.1.36', 'port' => 26379},
+     ]
+   ```
+
+1. Setup Sidekiq's connection to Gitaly:
+
+   ```ruby
+   git_data_dirs({
+     'default' => { 'gitaly_address' => 'tcp://gitaly:8075' },
+   })
+   gitlab_rails['gitaly_token'] = 'YOUR_TOKEN'
+   ```
+
+1. Setup Sidekiq's connection to Postgres:
+
+   ```ruby
+   gitlab_rails['db_host'] = '10.10.1.30'
+   gitlab_rails['db_password'] = 'YOUR_PASSOWORD'
+   gitlab_rails['db_port'] = '5432'
+   gitlab_rails['db_adapter'] = 'postgresql'
+   gitlab_rails['db_encoding'] = 'unicode'
+   gitlab_rails['auto_migrate'] = false
+   ```
+
+   Remember to add the Sidekiq nodes to the Postgres whitelist:
+
+   ```ruby
+   postgresql['trust_auth_cidr_addresses'] = %w(127.0.0.1/32 10.10.1.30/32 10.10.1.31/32 10.10.1.32/32 10.10.1.33/32 10.10.1.38/32)
+   ```
+
+1. Disable other services:
+
+   ```ruby
+   nginx['enable'] = false
+   grafana['enable'] = false
+   prometheus['enable'] = false
+   gitlab_rails['auto_migrate'] = false
+   alertmanager['enable'] = false
+   gitaly['enable'] = false
+   gitlab_monitor['enable'] = false
+   gitlab_workhorse['enable'] = false
+   nginx['enable'] = false
+   postgres_exporter['enable'] = false
+   postgresql['enable'] = false
+   redis['enable'] = false
+   redis_exporter['enable'] = false
+   unicorn['enable'] = false
+   gitlab_exporter['enable'] = false
+   ```
+
+1. Run `gitlab-ctl reconfigure`.
+
+## Example configuration
+
+Here's what the ending `/etc/gitlab/gitlab.rb` would look like:
+
+```ruby
+########################################
+#####        Services Disabled       ###
+########################################
+
+nginx['enable'] = false
+grafana['enable'] = false
+prometheus['enable'] = false
+gitlab_rails['auto_migrate'] = false
+alertmanager['enable'] = false
+gitaly['enable'] = false
+gitlab_monitor['enable'] = false
+gitlab_workhorse['enable'] = false
+nginx['enable'] = false
+postgres_exporter['enable'] = false
+postgresql['enable'] = false
+redis['enable'] = false
+redis_exporter['enable'] = false
+unicorn['enable'] = false
+gitlab_exporter['enable'] = false
+
+########################################
+####              Redis              ###
+########################################
+
+## Must be the same in every sentinel node
+redis['master_name'] = 'gitlab-redis'
+
+## The same password for Redis authentication you set up for the master node.
+redis['master_password'] = 'YOUR_PASSOWORD'
+
+## A list of sentinels with `host` and `port`
+gitlab_rails['redis_sentinels'] = [
+    {'host' => '10.10.1.34', 'port' => 26379},
+    {'host' => '10.10.1.35', 'port' => 26379},
+    {'host' => '10.10.1.36', 'port' => 26379},
+  ]
+
+#######################################
+###              Gitaly             ###
+#######################################
+
+git_data_dirs({
+  'default' => { 'gitaly_address' => 'tcp://gitaly:8075' },
+})
+gitlab_rails['gitaly_token'] = 'YOUR_TOKEN'
+
+#######################################
+###            Postgres             ###
+#######################################
+gitlab_rails['db_host'] = '10.10.1.30'
+gitlab_rails['db_password'] = 'YOUR_PASSOWORD'
+gitlab_rails['db_port'] = '5432'
+gitlab_rails['db_adapter'] = 'postgresql'
+gitlab_rails['db_encoding'] = 'unicode'
+gitlab_rails['auto_migrate'] = false
+
+#######################################
+###      Sidekiq configuration      ###
+#######################################
+sidekiq['listen_address'] = "10.10.1.48"
+
+#######################################
+###     Monitoring configuration    ###
+#######################################
+consul['enable'] = true
+consul['monitoring_service_discovery'] =  true
+
+consul['configuration'] = {
+  bind_addr: '10.10.1.48',
+  retry_join: %w(10.10.1.34 10.10.1.35 10.10.1.36)
+}
+
+# Set the network addresses that the exporters will listen on
+node_exporter['listen_address'] = '10.10.1.48:9100'
+
+# Rails Status for prometheus
+gitlab_rails['monitoring_whitelist'] = ['10.10.1.42', '127.0.0.1']
+```
+
+## Further reading
+
+Related Sidekiq configuration:
+
+1. [Extra Sidekiq processes](../operations/extra_sidekiq_processes.md)
+1. [Using the GitLab-Sidekiq chart](https://docs.gitlab.com/charts/charts/gitlab/sidekiq/)