This builds a lightweight Docker image containing Packer for creating virtual machine images (e.g. AWS EC2 instances).
Pass inputs in using volumes and environment variables.
docker run \
--rm \
--tty \
--interactive \
--volume /path/to/some/packer.json:/packer.json \
d11wtq/packer:0.8.5 \
packer build \
-var aws_region=$AWS_REGION \
-var aws_access_key=$AWS_ACCESS_KEY_ID \
-var aws_secret_key=$AWS_SECRET_ACCESS_KEY \
/packer.json