I’d suggest setting up your runners using the docker executor - https://docs.gitlab.com/runner/executors/docker.html This allows your runner to start up fresh containers for jobs with the image you specify, meaning jobs aren’t running on the host and can have whatever you need. You can then also use a single runner with parallelism instead of multiple runners. Downside is that if you need to install extras they will need to install as part of the CI on every job. More on reddit.com

It turned out I needed to add the gitlab-runner user to the docker group and stop running commands with sudo as you said . More on reddit.com

First q - nope! When people refer to the executor, they (should) only mean "the mechanism of which will be the acting environment for your pipeline commands to run in". If you use a shell-executor, it could be performed by the docker install or the binary install of the runner, and same for the docker-executor 2. Performance can be a bit of an issue - the trade off with dockerized builds are that 1 computer/VM can run multiple, simultaneous, totally isolated pipelines, whereas a shell runner can only safely run 1. While performance might drop off, there's the gain of not having to have several machines/vm's created (much more overhead from a full-os vs just a container). For context, I see network latency increase when I use a docker-windows executor running 5 different queued pipeline tasks on this 1 machine (16gb Ram, 8 CPU) and some CPU drop off, but if I were to spin up 5 different machines to handle this same work load (5 pipeline tasks queued at the same time, I'm probably not fully utilizing the resources but I definitely am hogging more resources that could be leveraged. Now taking into consideration that you have both a shell & a docker executor, it would depend on what kind of code you're pipeline is working with and how a build consumes resources - if you are building a java project, it would be hard to see a performance impact unless it's true massive, but for something like NodeJS with tons of packages, it would definitely cause impact if the shell runner executed a job while the docker executor took a few jobs as well, if say, using that same 16gb RAM & 8 Core machine. For some organization, I've kept shell runners on their own machine, because if someone edits their gitlab ci file to do something that affects the shell runner permanently (like "sudo apt upgrade", or something that causes a variable to linger beyond the build that affects the next build) then I have to worry about fixing that issue. There are good use cases for the shell runners though, but the docker executors provide the quickest way to scale pipelines to 100+ repositories, averaging 10 builds an hour during work hours (20 min pipeline execution). In some sort of motivational stance, if you have the extra machine power waiting around, I think you should be adding more features into your pipeline, which would then show you the need for the simultaneous task execution. Gitlab 's SAST jobs, coverage testing, linting, or even live execution of code for smoke tests or things of that nature could be explored to add value to the pipelines. All those combined would create a lengthy pipeline execution time, so there's more reason to attempt to run as many as these in parallel as possible. More on reddit.com

Pretty sure the answer is no, no way to explicitly tell it to ignore SSL errors. https://docs.gitlab.com/runner/configuration/advanced-configuration.html From a security perspective its probably worth the effort to get your certs working though. https://docs.gitlab.com/runner/configuration/tls-self-signed.html Its mostly just putting your root cert / self signed cert in the `/etc/gitlab-runner/certs` directory. More on reddit.com