Ansible typically runs on your local computer and carries out tasks on a remote server. If your local computer cannot run Ansible, you can also run Ansible on some server somewhere (including the server you wish to install to).
We're not sure what's the minimum version of Ansible that can run this playbook successfully. The lowest version that we've confirmed (on 2022-11-26) to be working fine is: `ansible-core` (`2.11.7`) combined with `ansible` (`4.10.0`).
If your distro ships with an Ansible version older than this, you may run into issues. Consider [Upgrading Ansible](#upgrading-ansible) or [using Ansible via Docker](#using-ansible-via-docker).
- by using an additional repository (PPA, etc.), which provides newer Ansible versions. See instructions for [CentOS](https://docs.ansible.com/ansible/latest/installation_guide/intro_installation.html#installing-ansible-on-rhel-centos-or-fedora), [Debian](https://docs.ansible.com/ansible/latest/installation_guide/intro_installation.html#installing-ansible-on-debian), or [Ubuntu](https://docs.ansible.com/ansible/latest/installation_guide/intro_installation.html#installing-ansible-on-ubuntu) on the Ansible website.
- by removing the Ansible package (`yum remove ansible` or `apt-get remove ansible`) and installing via [pip](https://pip.pypa.io/en/stable/installation/) (`pip install ansible`).
If using the `pip` method, do note that the `ansible-playbook` binary may not be on the `$PATH` (https://linuxconfig.org/linux-path-environment-variable), but in some more special location like `/usr/local/bin/ansible-playbook`. You may need to invoke it using the full path.
**Note**: Both of the above methods are a bad way to run system software such as Ansible. If you find yourself needing to resort to such hacks, please consider reporting a bug to your distribution and/or switching to a sane distribution, which provides up-to-date software.
Alternatively, you can run Ansible inside a Docker container (powered by the [devture/ansible](https://hub.docker.com/r/devture/ansible/) Docker image).
You can either [run Ansible in a container on the Matrix server itself](#running-ansible-in-a-container-on-the-matrix-server-itself) or [run Ansible in a container on another computer (not the Matrix server)](#running-ansible-in-a-container-on-another-computer-not-the-matrix-server).
To run Ansible in a (Docker) container on the Matrix server itself, you need to have a working Docker installation. Docker is normally installed by the playbook, so this may be a bit of a chicken and egg problem. To solve it:
- you **either** need to install Docker manually first. Follow [the upstream instructions](https://docs.docker.com/engine/install/) for your distribution and consider setting `matrix_playbook_docker_installation_enabled: false` in your `vars.yml` file, to prevent the playbook from installing Docker
- **or** you need to run the playbook in another way (e.g. [Running Ansible in a container on another computer (not the Matrix server)](#running-ansible-in-a-container-on-another-computer-not-the-matrix-server)) at least the first time around
Once you have a working Docker installation on the server, **clone the playbook** somewhere on the server and configure it as per usual (`inventory/hosts`, `inventory/host_vars/..`, etc.), as described in [configuring the playbook](configuring-playbook.md).
You would then need to add `ansible_connection=community.docker.nsenter` to the host line in `inventory/hosts`. This tells Ansible to connect to the "remote" machine by switching Linux namespaces with [nsenter](https://man7.org/linux/man-pages/man1/nsenter.1.html), instead of using SSH.
Alternatively, you can leave your `inventory/hosts` as is and specify the connection type in **each**`ansible-playbook` call you do later, like this: `ansible-playbook --connection=community.docker.nsenter ...`
Once you execute the above command, you'll be dropped into a `/work` directory inside a Docker container. The `/work` directory contains the playbook's code.
The above command tries to mount an SSH key (`$HOME/.ssh/id_rsa`) into the container (at `/root/.ssh/id_rsa`). If your SSH key is at a different path (not in `$HOME/.ssh/id_rsa`), adjust that part.
Once you execute the above command, you'll be dropped into a `/work` directory inside a Docker container. The `/work` directory contains the playbook's code.
To authenticate at your server using a password, you need to add a package. So, when you are in the shell of the ansible docker container (the previously used `docker run -it ...` command), run:
Because you're `root` in the container running Ansible and this likely differs fom the owner (your regular user account) of the playbook directory outside of the container, certain playbook features which use `git` locally may report warnings such as:
> fatal: unsafe repository ('/work' is owned by someone else)
> To add an exception for this directory, call:
> git config --global --add safe.directory /work
These errors can be resolved by making `git` trust the playbook directory by running `git config --global --add safe.directory /work`
