debian-mirror-gitlab/doc/administration/gitaly/index.md

Gitaly

Gitaly (introduced in GitLab 9.0) is a service that provides high-level RPC access to Git repositories. Gitaly was optional when it was first introduced in GitLab, but since GitLab 9.4 it is a mandatory component of the application.

GitLab components that access Git repositories (gitlab-rails, gitlab-shell, gitlab-workhorse) act as clients to Gitaly. End users do not have direct access to Gitaly.

Configuring Gitaly

The Gitaly service itself is configured via a TOML configuration file. This file is documented in the gitaly repository.

To change a Gitaly setting in Omnibus you can use gitaly['my_setting'] in /etc/gitlab/gitlab.rb. Changes will be applied when you run gitlab-ctl reconfigure.

gitaly['prometheus_listen_addr'] = 'localhost:9236'

To change a Gitaly setting in installations from source you can edit /home/git/gitaly/config.toml. Changes will be applied when you run service gitlab restart.

prometheus_listen_addr = "localhost:9236"

Client-side GRPC logs

Gitaly uses the gRPC RPC framework. The Ruby gRPC client has its own log file which may contain useful information when you are seeing Gitaly errors. You can control the log level of the gRPC client with the GRPC_LOG_LEVEL environment variable. The default level is WARN.

Running Gitaly on its own server

This is an optional way to deploy Gitaly which can benefit GitLab installations that are larger than a single machine. Most installations will be better served with the default configuration used by Omnibus and the GitLab source installation guide.

Starting with GitLab 9.4 it is possible to run Gitaly on a different server from the rest of the application. This can improve performance when running GitLab with its repositories stored on an NFS server.

At the moment (GitLab 9.4) Gitaly is not yet a replacement for NFS because some parts of GitLab still bypass Gitaly when accessing Git repositories. If you choose to deploy Gitaly on your NFS server you must still also mount your Git shares on your GitLab application servers.

Gitaly network traffic is unencrypted so you should use a firewall to restrict access to your Gitaly server.

Below we describe how to configure a Gitaly server at address gitaly.internal:8075 with secret token abc123secret. We assume your GitLab installation has two repository storages, default and storage1.

Client side token configuration

Start by configuring a token on the client side.

Omnibus installations:

# /etc/gitlab/gitlab.rb
gitlab_rails['gitaly_token'] = 'abc123secret'

Source installations:

# /home/git/gitlab/config/gitlab.yml
gitlab:
  gitaly:
    token: 'abc123secret'

You need to reconfigure (Omnibus) or restart (source) for these changes to be picked up.

Gitaly server configuration

Next, on the Gitaly server, we need to configure storage paths, enable the network listener and configure the token.

Note: if you want to reduce the risk of downtime when you enable authentication you can temporarily disable enforcement, see the documentation on configuring Gitaly authentication .

Gitaly must trigger some callbacks to GitLab via GitLab Shell. As a result, the GitLab Shell secret must be the same between the other GitLab servers and the Gitaly server. The easiest way to accomplish this is to copy /etc/gitlab/gitlab-secrets.json from an existing GitLab server to the Gitaly server. Without this shared secret, Git operations in GitLab will result in an API error.

NOTE: In most or all cases the storage paths below end in /repositories which is different than path in git_data_dirs of Omnibus installations. Check the directory layout on your Gitaly server to be sure.

Omnibus installations:

# /etc/gitlab/gitlab.rb

# Avoid running unnecessary services on the gitaly server
postgresql['enable'] = false
redis['enable'] = false
nginx['enable'] = false
prometheus['enable'] = false
unicorn['enable'] = false
sidekiq['enable'] = false
gitlab_workhorse['enable'] = false

# Prevent database connections during 'gitlab-ctl reconfigure'
gitlab_rails['rake_cache_clear'] = false
gitlab_rails['auto_migrate'] = false

# Configure the gitlab-shell API callback URL. Without this, `git push` will
# fail. This can be your 'front door' GitLab URL or an internal load
# balancer.
gitlab_rails['internal_api_url'] = 'https://gitlab.example.com'

# Make Gitaly accept connections on all network interfaces. You must use
# firewalls to restrict access to this address/port.
gitaly['listen_addr'] = "0.0.0.0:8075"
gitaly['auth_token'] = 'abc123secret'

gitaly['storage'] = [
  { 'name' => 'default', 'path' => '/mnt/gitlab/default/repositories' },
  { 'name' => 'storage1', 'path' => '/mnt/gitlab/storage1/repositories' },
]

Source installations:

# /home/git/gitaly/config.toml
listen_addr = '0.0.0.0:8075'

[auth]
token = 'abc123secret'

[[storage]]
name = 'default'
path = '/mnt/gitlab/default/repositories'

[[storage]]
name = 'storage1'
path = '/mnt/gitlab/storage1/repositories'

Again, reconfigure (Omnibus) or restart (source).

Converting clients to use the Gitaly server

Now as the final step update the client machines to switch from using their local Gitaly service to the new Gitaly server you just configured. This is a risky step because if there is any sort of network, firewall, or name resolution problem preventing your GitLab server from reaching the Gitaly server then all Gitaly requests will fail.

We assume that your Gitaly server can be reached at gitaly.internal:8075 from your GitLab server, and that your GitLab NFS shares are mounted at /mnt/gitlab/default and /mnt/gitlab/storage1 respectively.

Omnibus installations:

# /etc/gitlab/gitlab.rb
git_data_dirs({
  'default' => { 'path' => '/mnt/gitlab/default', 'gitaly_address' => 'tcp://gitaly.internal:8075' },
  'storage1' => { 'path' => '/mnt/gitlab/storage1', 'gitaly_address' => 'tcp://gitaly.internal:8075' },
})

gitlab_rails['gitaly_token'] = 'abc123secret'

Source installations:

# /home/git/gitlab/config/gitlab.yml
gitlab:
  repositories:
    storages:
      default:
        path: /mnt/gitlab/default/repositories
        gitaly_address: tcp://gitaly.internal:8075
      storage1:
        path: /mnt/gitlab/storage1/repositories
        gitaly_address: tcp://gitaly.internal:8075

  gitaly:
    token: 'abc123secret'

Now reconfigure (Omnibus) or restart (source). When you tail the Gitaly logs on your Gitaly server (sudo gitlab-ctl tail gitaly or tail -f /home/git/gitlab/log/gitaly.log) you should see requests coming in. One sure way to trigger a Gitaly request is to clone a repository from your GitLab server over HTTP.

Disabling or enabling the Gitaly service in a cluster environment

If you are running Gitaly as a remote service you may want to disable the local Gitaly service that runs on your GitLab server by default.

'Disabling Gitaly' only makes sense when you run GitLab in a custom cluster configuration, where different services run on different machines. Disabling Gitaly on all machines in the cluster is not a valid configuration.

If you are setting up a GitLab cluster where Gitaly does not need to run on all machines, you can disable the Gitaly service in your Omnibus installation, add the following line to /etc/gitlab/gitlab.rb:

gitaly['enable'] = false

When you run gitlab-ctl reconfigure the Gitaly service will be disabled.

To disable the Gitaly service in a GitLab cluster where you installed GitLab from source, add the following to /etc/default/gitlab on the machine where you want to disable Gitaly.

gitaly_enabled=false

When you run service gitlab restart Gitaly will be disabled on this particular machine.