This reference setup guides users through the setup based on `docker-compose`, but the installation
of `docker-compose` is out of scope of this documentation. To install `docker-compose` itself, follow
the official [install instructions](https://docs.docker.com/compose/install/).
## Basics
The most simple setup just creates a volume and a network and starts the `gitea/gitea:latest-rootless`
image as a service. Since there is no database available, one can be initialized using SQLite3.
Create a directory for `data` and `config` then paste the following content into a file named `docker-compose.yml`.
Note that the volume should be owned by the user/group with the UID/GID specified in the config file. By default Gitea in docker will use uid:1000 gid:1000. If needed you can set ownership on those folders with the command: `sudo chown 1000:1000 config/ data/`
If you don't give the volume correct permissions, the container may not start.
For a stable release you could use `:latest-rootless`, `:1-rootless` or specify a certain release like `:{{< version >}}-rootless`, but if you'd like to use the latest development version then `:dev-rootless` would be an appropriate tag. If you'd like to run the latest commit from a release branch you can use the `:1.x-dev-rootless` tag, where x is the minor version of Gitea. (e.g. `:1.16-dev-rootless`)
In addition to the environment variables above, any settings in `app.ini` can be set or overridden with an environment variable of the form: `GITEA__SECTION_NAME__KEY_NAME`. These settings are applied each time the docker container starts. Full information [here](https://github.com/go-gitea/gitea/tree/main/contrib/environment-to-ini).
These environment variables can be passed to the docker container in `docker-compose.yml`. The following example will enable an smtp mail server if the required env variables `GITEA__mailer__FROM`, `GITEA__mailer__HOST`, `GITEA__mailer__PASSWD` are set on the host or in a `.env` file in the same directory as `docker-compose.yml`:
```bash
...
services:
server:
environment:
- GITEA__mailer__ENABLED=true
- GITEA__mailer__FROM=${GITEA__mailer__FROM:?GITEA__mailer__FROM not set}
- GITEA__mailer__MAILER_TYPE=smtp
- GITEA__mailer__HOST=${GITEA__mailer__HOST:?GITEA__mailer__HOST not set}
To set required TOKEN and SECRET values, consider using Gitea's built-in [generate utility functions](https://docs.gitea.io/en-us/command-line/#generate).
Since SSH is running inside the container, SSH needs to be passed through from the host to the container if SSH support is desired. One option would be to run the container SSH on a non-standard port (or moving the host port to a non-standard port). Another option which might be more straightforward is to forward SSH commands from the host to the container. This setup is explained in the following.
This guide assumes that you have created a user on the host called `git` with permission to run `docker exec`, and that the Gitea container is called `gitea`. You will need to modify that user's shell to forward the commands to the `sh` executable inside the container, using `docker exec`.
Now that all the SSH commands are forwarded to the container, you need to set up the SSH authentication on the host. This is done by leveraging the [SSH AuthorizedKeysCommand](https://docs.gitea.io/en-us/command-line/#keys) to match the keys against those accepted by Gitea. Add the following block to `/etc/ssh/sshd_config`, on the host:
