Fixing Docker Permissions in the Self-Hosted Runner Image
While testing the multi-runner setup I discovered containers started by the runner user could not invoke Docker. The base image lacked the docker.io package and the user was missing membership of the docker group.
The Dockerfile.ubuntu-runner now installs Docker and ensures the runner user belongs to the docker group so each containerised runner can start sibling containers without needing root:
@@ -RUN apt-get update && apt-get install -y \ - curl git jq sudo nodejs npm \ - libicu70 libssl-dev libcurl4-openssl-dev \ +RUN apt-get update && apt-get install -y \ + curl git jq sudo nodejs npm \ + libicu70 libssl-dev libcurl4-openssl-dev \ + docker.