Docs: improve podman installation guide by adding information about aardvark-dns bug
Problem to solve
Affected documentation: Use Podman to run Docker commands
I recently setup a GitLab runner on an Ubuntu 24.04 LTS system and decided to use rootless podman as container runtime for the docker executor. On Ubuntu 24.04 (noble) repositories, podman version 4.9.3 is included. Because this podman version fulfills the prerequisites stated in the documentation (4.2.0 or later) I used that. To use services I also enabled the runner feature flag FF_NETWORK_PER_BUILD. While testing the runner setup I experienced some random sporadic DNS failures, where sometimes repository checkout fails because it couldn't resolve the gitlab server domain or scripts running in the container couldn't resolve a domain I was able to resolve on the host or by manually spinning up a container.
After researching for some days and testing different things like explicitly setting DNS server IPs and search domains in the runner config.toml (that did not help), I stumbled across a gitlab forum post that describes a similar setup. An answer by jwillikers links to the github issue DNS requests timeout - aardvark-dns which describes the same sporadic DNS failures I experienced.
Proposal
At least as long the fixed version has not made its way into all current Linux distros (debian bookworm and Ubuntu LTS contain 1.4.0).