ctorgalson.get_docker

(ctorgalson/ansible-role-get-docker)

This role retrieves and runs the script from https://get.docker.com. It offers three install strategies for different situations:

install-only (when the docker binary can not be located),
commit-hash based (when the install script matches a configurable commit hash),
force (always run the install script).

The role attempts to provide a small amount of additional security over simply downloading and installing the role by comparing the script downloaded from https://get.docker.com, and the version hosted on github.com.

If the diff of the two files is more than a single line, or if the single line does not match the $SCRIPT_COMMIT_SHA assignment line, the role will not attempt the install.

There are other, more sophisticated (and much more widely-used) Ansible roles for installing Docker. Unless you have specific reasons for using the shell script installer from https://get.docker.com you should probably use one of those instead. For example, I've used both of the following roles with good results:

Requirements

The only requirement of the role is that (per Docker's advice), it should only be run on machines if:

the machine does not already have docker-ce installed,
the machine has previously had docker-ce installed by https://get.docker.com.

If you're trying to use this role to install docker-ce alongside other docker* packages, please be sure you know what you're doing.

Role Variables

Defaults

Variable name	Default value	Required	Description
`gd__force_install_script`	`false`	no	Forces the installer to run even if Docker has already been installed.
`gd__script_commit_sha`	`undefined`	no	When set, the installer will only run if its `$SCRIPT_COMMIT_SHA` variable is set to this value.

Vars

Variable name	Default value	Required	Description
`gd__bin_path`	`/usr/bin/docker`	yes	The path the role should search to see if Docker is already installed.
`gd__get_docker_com`	`https://get.docker.com`	yes	The URL of the downloadable Docker install script.
`gd__install_sh_url`	`https://raw.githubusercontent.com/docker/docker-install/master/install.sh`	yes	The URL of the github.com-hosted, pre-build get.docker.com install script. Compared with get.docker.com script for increased install safety.

Dependencies

The role does not depend on any other roles.

Example Playbook

The role will install Docker once given this configuration. In concert with unattended upgrades, this will do for many situations, but it's up to you to keep it up-to-date. See the Variables section above for more info.

---
- name: Install Docker.
  hosts: all
  gather_facts: false
  tasks:
    - name: "Include ctorgalson.get_docker"
      ansible.builtin.include_role:
        name: "ctorgalson.get_docker"

License

GPL-3.0-only

Author Information

Christopher Torgalson