Configure Gerrit git repositories replication

Introduction

Software Factory can replicate git repositories to remote git servers. This feature relies on Gerrit’s replication plugin.

The replication settings can be changed in the config repository; they can be found in the directory “gerrit” you will find a file called replication.config.

The replication of repositories should be done using the SSH protocol. By default Software Factory will use its own SSH private key to authenticate against the remote server.

Configure the replication for a repository

As a project’s maintainer, I want to setup the replication of my repositories myproject-client and myproject-server to a remote server. So I have to submit a patch to the config repository.

Clone the config repository:

$ git clone https://<fqdn>/r/config

Edit the file gerrit/replication.config and add the following:

[remote "example-mirror"]
    url = sf@mirrors.domain.example:/home/mirror/git/${name}.git
    mirror = true
    projects = ^myproject-.*

Here we configure the replication to replicate repositories where names match the regular expression “^myproject-.*” to the remote server mirrors.domain.example. The special placeholder “${name}” is needed here because the regular expression will match several repositories. The “mirror” option is set to true to replicate branch deletion.

Note

Software Factory’s replication support is based on Gerrit’s own replication plugin. More information on available options can be found in the Replication README.

Then commit and send the patch for review.

$ git commit -m'Add replication for myproject suite'
$ git review

Once the patch is merged the config-update job will trigger the replication to mirrors.domain.example (in that example).

Note

The public key used for the replication needs to be added to the .ssh/authorized_keys of the sf user on mirrors.domain.example.

See the Gerrit replication operator documentation

Note

If mirrors.domain.example has never been used as a replication target, then the Software Factory administrator should add the server’s host key to the known_hosts file on Software Factory’s Gerrit node.

Note

There is no need to create the bare git repository on the remote server as long as a regular shell is available on the target. The replication plugin will create the repository if it does not exist.

Get the replication SSH public key

Gerrit SSH public key is available at the following URL.

$ curl -OL https://<fqdn>/keys/gerrit_service_rsa.pub

Configuring repository replication on Github

There are two solutions you may use to replicate on Github:

• Define a deployment key in your github repository’s settings
• Add a collaborator to your github repository’s settings

The former is less straigtforward than the latter, and involve more work from the Software Factory administrator, because the replication plugin will by default use its own key to authenticate against Github. However each deployment key on GitHub must be unique so you will have to create a key pair and request your Software Factory administrator to add the private key on Software Factory.

The latter does not require any specific configuration from the Software Factory administrator. As a Github project owner you should add a collaborator, and register the Software Factory public key in the “SSH key” section of the Github user settings. Software Factory will then act on behalf of that Github user for the replication. Please ask your Software Factory administrator if a specific user on Github already exists for replication purposes.

Note

Software Factory won’t create repositories on Github if they do not exist. They must be created manually.