Do you guys expose the docker socket to any of your containers or is that a strict no-no? What are your thoughts behind it if you don’t? How do you justify this decision from a security standpoint if you do?

I am still fairly new to docker but I like the idea of something like Watchtower. Even though I am not a fan of auto-updates and I probably wouldn’t use that feature I still find it interesting to get a notification if some container needs an update. However, it needs to have access to the docker socket to do its work and I read a lot about that and that this is a bad idea which can result in root access on your host filesystem from within a container.

There are probably other containers as well especially in this whole monitoring and maintenance category, that need that privilege, so I wanted to ask how other people handle this situation.

Cheers!

  • moonpiedumplings@programming.devEnglish
    1·
    18 hours ago

    I’ve seen three cases where the docker socket gets exposed to the container (perhaps there are more but I haven’t seen any?):

    1. Watchtower, which does auto updates and/or notifies people

    2. Nextcloud AIO, which uses a management container that controls the docker socket to deploy the rest of the stuff nextcloud wants.

    3. Traefik, which reads the docker socket to automatically reverse proxy services.

    Nextcloud does the AIO, because Nextcloud is a complex service, but it grows to be very complex if you want more features or performance. The AIO handles deploying all the tertiary services for you, but something like this is how you would do it yourself: https://github.com/pimylifeup/compose/blob/main/nextcloud/signed/compose.yaml . Also, that example docker compose does not include other services, like collabara office, which is the google docs/sheets/slides alternative, a web based office.

    Compare this to the kubernetes deployment, which yes, may look intimidating at first. But actually, many of the complexities that the docker deploy of nextcloud has are automated away. Enabling the Collabara office is just collabara.enabled: true in the configuration of it. Tertiary services like Redis or the database, are included in the Kubernetes package as well. Instead of configuring the containers itself, it lets you configure the database parameters via yaml, and other nice things.

    For case 3, Kubernetes has a feature called an “Ingress”, which is essentially a standardized configuration for a reverse proxy that you can either separate out, or one is provided as part of the packages. For example, the nextcloud kubernetes package I linked above, has a way to handle ingresses in the config.

    Kubernetes handles these things pretty well, and it’s part of why I switched. I do auto upgrade, but I only auto upgrade my services, within the supported stable release, which is compatible for auto upgrades and won’t break anything. This enables me to get automatic security updates for a period of time, before having to do a manual and potentially breaking upgrade.

    TLDR: You are asking questions that Kubernetes has answers to.