This is an example lightweight Docker image build using Ansible which builds a usable Hubot chat bot that works with Slack. The example is explained in more detail in Chapter 13 of Ansible for DevOps.
Follow the instructions in Slack's guide, Slack Developer Kit for Hubot, and get an API token for a bot attached to a new App installed in the workspace of a Slack organization.
Make sure you have Docker installed on the workstation or VM where this playbook is located, then enter the command:
$ ansible-playbook main.yml
This will generate a Docker image named a4d/hubot-slack, which you should see listed when you run docker images.
To run the image, run the command below, replacing TOKEN_HERE with the API token your bot uses from Slack:
$ docker run -d --name hubot -e HUBOT_SLACK_TOKEN=TOKEN_HERE a4d/hubot-slack
The container should be running in the background. You can inspect the logs from the bot using docker logs hubot, and you can kill and remove the container with docker rm -f hubot.
This project was created by Jeff Geerling as an example for Ansible for DevOps.