Mounting docker command into jenkins container

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1

Hi, I’m trying to redirect docker binary and docker.sock into my jenkins docker container so it can use docker in its pipeline operations. I’m getting the following error when I do this:
bash: /usr/bin/docker: cannot execute: required file not found

here are the steps I followed;

  1. I get the absolute path of my host docker binary by doing readlink -f $(which docker)
  2. I created a docker-compose file. here are the contents;
version: "3"
services:
  jenkins:
    image: jenkins/jenkins:lts
    privileged: true
    user: root
    ports:
      - 8080:8080
      - 50000:50000
    container_name: jenkins
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - /nix/store/pah5a5r2kyzdzac2115xsgzgnpypf6ps-docker-24.0.5/bin/docker:/usr/bin/docker
  1. I run the jenkins container and got into jenkins container shell. run docker and got the following error: bash: /usr/bin/docker: cannot execute: required file not found

does anyone know how to fix this?
I can provide more information if necessary

2

I believe what it can’t find is the DT_INTERP, the glibc dynamic linker, because this points into the Nix store.
You might try mounting the nix store into the container:

    ...
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - /nix/store:/nix/store
      - /nix/store/pah5a5r2kyzdzac2115xsgzgnpypf6ps-docker-24.0.5/bin/docker:/usr/bin/docker

Note that hardcoding a store path into your Docker Compose file may be a bad idea, as nix store paths can eventually be GC’d. If you perform a nix build nixpkgs#docker or nix-build '<nixpkgs>' -A docker (pre-flake), you should get a result symlink in the current folder; that will act as a GC root that pins the store path that it points to from being GC’d as long as the directory is not removed or renamed. This isn’t a bullet proof solution, but I can’t think of a more intricate solution that might suit your workflow, off-hand.

1 Like
3

mounting /nix/store solved the problem. you saved me from installing ubuntu server. thank you.