[Howto] My own mail & groupware server, part 3: Git server

Running your own mail and groupware server can be challenging. I recently had to re-create my own setup from the ground and describe the steps in a blog post series. This blog post is #3 of the series and covers the integration of an additional Git server setup.

This post is all about setting up an additional Git server to the existing mail server. Read about the background to this setup in the first post, part 1: what, why, how?, and all about the mail server setup itself in the second post, part 2: initial mail server setup.

Gitea as Git server

I heavily use Git all the time. And there are enough information where I feel more comfortable when I host them only on infrastructure I control. So for the new setup I also wanted to have a Git server, as fast as possible.

In the past I used Gitlab as Git server, but that is very resource intensive and just overkill for my use cases. Thus years ago I already replaced Gitlab with Gitea – a lightweight, painless self-hosted git service. It is quickly set up, simple to use, offers nevertheless all relevant Git features, and simply does it’s job. Gitea itself is a fork of Gogs, which was not really community friendly. These days Gitea is a way more active and prospering project than Gogs.

Background: Nginx as reverse proxy in Mailu

So how do you “attach” Gitea to a running Mailu infrastructure? Mailu itself comes with a set of defined services, and that’s it. There is no plugin or module system to extend it. However, the project does offer special “overrides” directories where additional configuration can be placed – this applies to Nginx as well! That way, a service can be placed right next to other Mailu services, behind the same reverse proxy, and that way benefit from the already existing setup and for example the certificate regeneration. Also, there is no problem with the already used ports 80 and 443, etc.

Overrides can be placed in /data/mailu/overrides/nginx. They are basically just snippets of Nginx configuration. Note though that they are included within the the main server block! That means they can only work on locations, not on server names. This is somewhat unfortunate since I used to address all my old services via sub-domains. git.bayz.de, nc.bayz.de, etc. With the new setup and the limit to locations this is not an option anymore, everything has to work on different working directories: bayz.de/git, bayz.de/nc, etc.

This is somewhat unfortunate, because that also meant that I had to reconfigure clients, and also ask others to reconfigure their clients when using my infrastructure. I would be happy to get back to a pure sub-domain based addressing, but I don’t see how this could be possible without changing the actual Nginx image.

Adding Gitea entry to Nginx Override

Having said that, to add Gitea to Nginx, create this file: /data/mailu/overrides/nginx/git.conf

location /gitea/ {
  proxy_pass http://git:3000/;
}

And that’s it already. More configuration is not needed since Mailu already configures Nginx with reasonable defaults.

This also gives a first hint that it is pretty easy to add further services – I will cover more examples in this ongoing blog post series.

Additional entry to docker compose

To start Gitea itself, add it to Mailu’s docker-compose.yml:

  # gitea

  git:
    image: gitea/gitea:latest
    restart: always
    env_file: mailu.env
    depends_on:
      - resolver
    dns:
      - 192.168.203.254
    volumes:
      - /data/gitea:/data
      - /etc/timezone:/etc/timezone:ro
      - /etc/localtime:/etc/localtime:ro
    ports:
      - "22:22"

Note the shared volumes: that way the Gitea configuration file will be written on your storage in /data/gitea/gitea/conf/app.ini .

Also, we want to set UID and GUID for Gitea via environment variables. Set this in your mailu.env:

###################################
# Gitea settings
###################################
USER_UID=1000
USER_GID=1000

Setting up Gitea basic configuration

Now let’s configure Gitea. It is possible to pre-create a full Gitea configuration and start the container with it. However, documentation on that is sparse and in my tests there were always problems.

So in my case, I just started and stopped the container (docker compose down and up) a few times, edited some configuration, once registered an admin user via the GUI and was done. While this worked, I can only recommend to closely track the logs during that time to ensure that no one else is accessing the container and does mischief!

So, the first step is to start the new Docker compose service. This will write a first vanilla configuration of Gitea. Afterwards, add the correct domain information in the [server] section in the Gitea configuration file app.ini:

DOMAIN = git.bayz.de
SSH_DOMAIN = git.bayz.de
ROOT_URL = https://git.bayz.de/gitea

Note that the ROOT_URL value ensures the required rewrite of all requests and links so that the setup works flawlessly with the above mentioned Nginx configuration!

Next, bring the service down and up again (Docker compose down and up), login to your new service (here: git.bayz.de/gitea ) and register a new admin user. Note that here you also have to pick the database option. For small systems with only very few concurrent connections sqlite is fine. If you will serve more users here, or automated access, pick Postgresql. However, to make that work you need to bring up another Postgresql container. One of the next posts will introduce one, so you might want to re-think your setup then.

Directly after this admin registration is done, in the Gitea configuration fileapp.ini in the [server] section change the value of DISABLE_REGISTRATION to true. Stop and start the service again, and no new (external) users can register anymore.

But how do we register new users now?

Central services authentication in Mailu: mail

One of the major hassles with my last setup was the authentication. I started with a fully blown OpenLDAP years ago, which was a pain to manage and maintain already. Moving over to FreeIPA meant that I had better interfaces and maybe even a UI, but it was still a complex, tricky service. Also while almost every service out there can be connected to LDAP, that is not always easy or a pleasant experience. And given that I only have a few users on my system, that is hardly worth the trouble.

Mailu offers an interesting approach here: users are stored in a DB, and external services are asked to authenticate against the email services (IMAP, SMTP). I was surprised to learn that indeed many services out there support this or have plugins for that.

Gitea can authenticate against SMTP sources, and I decided to go that route:

In Gitea, access “Site Administration”
Click on “Authentication Sources”
Pick the blue button “Add Authentication Source”
As “Authentication Type“, choose SMTP
Give it a name
As “SMTP Authentication Type“, enter LOGIN
As “SMTP Host“, provide the external host name here (more on that further down below) lisa.bayz.de
Pick the right “SMTP Port“, 587
And limit the “Allowed Domains” if you want, in my case to bayz.de
Of course, tick the check box “Enable TLS Encryption” and also the check box “This Authentication Source is Activated“

After this is done, log out of Gitea and log in with an existing mail user. It should just work! And that all without any trace of LDAP! Awesome, right?

A word about the SMTP host in the above configuration: do not try to enter here the SMTP docker compose service directly. This will not work: port 587 is managed by the Nginx proxy which acts as mail proxy here, which redirects auth mail requests to the admin portal. The internal SMTP container does not even listen on port 587.

What’s next?

With my private Git server back to live I felt slightly better again. Now I had the infrastructure at my hands I needed to tackle the cloud/file sharing part of all of it to also lay the foundations for the groupware pieces: Nextcloud.