Linux Administration Cookbook

Packer

Say we don't want to just use the container from Docker Hub. Say we want to tweak it slightly before we deploy it using Terraform.

This is where Packer comes in, which is a very versatile tool. Packer has builders for AWS, Scaleway, LXC, VirtualBox, QEMU, and others, but the one we're interested in is Docker.

Head back into your home directory and create an example-packer directory:

$ cd ~$ mkdir example-packer$ cd example-packer

Next, output the following to a file:

$ cat <<HERE > docker.json{   "builders":[  {    "type": "docker",    "image": "nginx",    "commit": true,    "pull": true,    "changes": [      "LABEL custom=true",      "EXPOSE 443"    ]  }],  "provisioners":[  {    "type": "shell",    "inline": ["echo 'Bring back Black Books!'","apt remove nginx -y"] }] ...