I finally get it…

I finally understand.

I have been avoiding Docker for a while now and sticking to VMs and LXC container templates.

Yesterday, I finally bit the bullet and was able to set up Docker with Portainer, and use Docker-Compose to create a stack with several containers, all connecting to the web through another that ran a VPN client.

I have quite a lot to learn, I spent several hours googling as I didn't understand that the existing dockercompose file from an image **does apply.** i.e. if you create a new image with a new dockerfile using **FROM** it will merge your new dockerfile with the one pulled from the image.

What an incredible thing docker is. Time to containerize ALL THE THINGS!

4 thoughts on “I finally get it…”

  1. Docker containers are layer, so essentially, yes.

    If you build something with say –

    FROM ubuntu
    do a thing
    and copy in a thing
    and do another thing

    and then save that as myubuntuimage, and then make another container –

    FROM myubuntuimage
    copy in more things
    execute some checks
    run a thing

    Your new image will start with your old image as the base layer, then layer your additions on top.

    Welcome to the wonderful world of containers! I miss that early “CONTAINERIZE ALL THE THINGS!” feeling 🙂 … enjoy it!

    Edit – I just re-read your post though and it sounds like you might be confused about a Dockerfile vs. a compose file.

    Dockerfiles, as above, are used to _create container images_.

    Compose files and compose are used to locally orchestrate the running of container images.

    Apples and oranges. Or, maybe, apples and appleseeds.

  2. I remember that feeling, and what a great feeling it was. Nowadays I manage a few servers and k8s clusters, everything in docker everywhere!

  3. I think one of the biggest advantages with docker containers is that you don’t get a bloated system with a bunch of crap installed. Everything is packaged in it’s own little environment and can be easily scrapped without affecting the rest of the system.

    Also, all your services as self documented with the docker-compose files.


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