Packer Docker Builder with remote docker daemon

Question

I'm using packer docker builder with ansible to create docker image

when I execute packer docker to build the image, it errors out saying:

   docker: Run command: docker run -v /root/.packer.d/tmp/packer-docker612435850:/packer-files -d -i -t ubuntu:latest /bin/bash

==> docker: Error running container: Docker exited with a non-zero exit status.

==> docker: Stderr: docker: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?.

==> docker: See 'docker run --help'.

Answer 1

Packers Docker builder doesn't work with remote hosts since packer uses the /packer-filesvolume mount to communicate with the container. This is vaguely expressed in the docs with:

The Docker builder must run on a machine that has Docker installed.