Add docker_obsolete_packages to README.

README.md

@@ -12,13 +12,15 @@ None.
 
 Available variables are listed below, along with default values (see `defaults/main.yml`):
 
-    # Edition can be one of: 'ce' (Community Edition) or 'ee' (Enterprise Edition).
-    docker_edition: 'ce'
-    docker_packages:
+```yaml
+# Edition can be one of: 'ce' (Community Edition) or 'ee' (Enterprise Edition).
+docker_edition: 'ce'
+docker_packages:
     - "docker-{{ docker_edition }}"
     - "docker-{{ docker_edition }}-cli"
     - "docker-{{ docker_edition }}-rootless-extras"
-    docker_packages_state: present
+docker_packages_state: present
+```
 
 The `docker_edition` should be either `ce` (Community Edition) or `ee` (Enterprise Edition). 
 You can also specify a specific version of Docker to install using the distribution-specific format: 
@@ -27,66 +29,96 @@ Debian/Ubuntu: `docker-{{ docker_edition }}=<VERSION>` (Note: you have to add th
 
 You can control whether the package is installed, uninstalled, or at the latest version by setting `docker_packages_state` to `present`, `absent`, or `latest`, respectively. Note that the Docker daemon will be automatically restarted if the Docker package is updated. This is a side effect of flushing all handlers (running any of the handlers that have been notified by this and any other role up to this point in the play).
 
-    docker_service_manage: true
-    docker_service_state: started
-    docker_service_enabled: true
-    docker_restart_handler_state: restarted
+```yaml
+docker_obsolete_packages:
+  - docker
+  - docker.io
+  - docker-engine
+  - podman-docker
+  - containerd
+  - runc
+```
+
+A list of packages to be uninstalled prior to running this role. See [Docker's installation instructions](https://docs.docker.com/engine/install/debian/#uninstall-old-versions) for an up-to-date list of old packages that should be removed.
+
+```yaml
+docker_service_manage: true
+docker_service_state: started
+docker_service_enabled: true
+docker_restart_handler_state: restarted
+```
 
 Variables to control the state of the `docker` service, and whether it should start on boot. If you're installing Docker inside a Docker container without systemd or sysvinit, you should set `docker_service_manage` to `false`.
 
-    docker_install_compose_plugin: false
-    docker_compose_package: docker-compose-plugin
-    docker_compose_package_state: present
+```yaml
+docker_install_compose_plugin: false
+docker_compose_package: docker-compose-plugin
+docker_compose_package_state: present
+```
 
 Docker Compose Plugin installation options. These differ from the below in that docker-compose is installed as a docker plugin (and used with `docker compose`) instead of a standalone binary.
 
-    docker_install_compose: true
-    docker_compose_version: "1.26.0"
-    docker_compose_arch: "{{ ansible_architecture }}"
-    docker_compose_path: /usr/local/bin/docker-compose
+```yaml
+docker_install_compose: true
+docker_compose_version: "1.26.0"
+docker_compose_arch: "{{ ansible_architecture }}"
+docker_compose_path: /usr/local/bin/docker-compose
+```
 
 Docker Compose installation options.
 
-    docker_add_repo: true
+```yaml
+docker_add_repo: true
+```
 
 Controls whether this role will add the official Docker repository. Set to `false` if you want to use the default docker packages for your system or manage the package repository on your own.
 
-    docker_repo_url: https://download.docker.com/linux
+```yaml
+docker_repo_url: https://download.docker.com/linux
+```
 
 The main Docker repo URL, common between Debian and RHEL systems.
 
-    docker_apt_release_channel: stable
-    docker_apt_arch: "{{ 'arm64' if ansible_architecture == 'aarch64' else 'amd64' }}"
-    docker_apt_repository: "deb [arch={{ docker_apt_arch }}] {{ docker_repo_url }}/{{ ansible_distribution | lower }} {{ ansible_distribution_release }} {{ docker_apt_release_channel }}"
-    docker_apt_ignore_key_error: True
-    docker_apt_gpg_key: "{{ docker_repo_url }}/{{ ansible_distribution | lower }}/gpg"
-    docker_apt_filename: "docker"
+```yaml
+docker_apt_release_channel: stable
+docker_apt_arch: "{{ 'arm64' if ansible_architecture == 'aarch64' else 'amd64' }}"
+docker_apt_repository: "deb [arch={{ docker_apt_arch }}] {{ docker_repo_url }}/{{ ansible_distribution | lower }} {{ ansible_distribution_release }} {{ docker_apt_release_channel }}"
+docker_apt_ignore_key_error: True
+docker_apt_gpg_key: "{{ docker_repo_url }}/{{ ansible_distribution | lower }}/gpg"
+docker_apt_filename: "docker"
+```
 
 (Used only for Debian/Ubuntu.) You can switch the channel to `nightly` if you want to use the Nightly release.
 
 You can change `docker_apt_gpg_key` to a different url if you are behind a firewall or provide a trustworthy mirror.
 Usually in combination with changing `docker_apt_repository` as well. `docker_apt_filename` controls the name of the source list file created in `sources.list.d`. If you are upgrading from an older (<7.0.0) version of this role, you should change this to the name of the existing file (e.g. `download_docker_com_linux_debian` on Debian) to avoid conflicting lists.
 
-    docker_yum_repo_url: "{{ docker_repo_url }}/{{ (ansible_distribution == 'Fedora') | ternary('fedora','centos') }}/docker-{{ docker_edition }}.repo"
-    docker_yum_repo_enable_nightly: '0'
-    docker_yum_repo_enable_test: '0'
-    docker_yum_gpg_key: "{{ docker_repo_url }}/centos/gpg"
+```yaml
+docker_yum_repo_url: "{{ docker_repo_url }}/{{ (ansible_distribution == 'Fedora') | ternary('fedora','centos') }}/docker-{{ docker_edition }}.repo"
+docker_yum_repo_enable_nightly: '0'
+docker_yum_repo_enable_test: '0'
+docker_yum_gpg_key: "{{ docker_repo_url }}/centos/gpg"
+```
 
 (Used only for RedHat/CentOS.) You can enable the Nightly or Test repo by setting the respective vars to `1`.
 
 You can change `docker_yum_gpg_key` to a different url if you are behind a firewall or provide a trustworthy mirror.
 Usually in combination with changing `docker_yum_repository` as well.
 
-    docker_users:
+```yaml
+docker_users:
   - user1
   - user2
+```
 
 A list of system users to be added to the `docker` group (so they can use Docker on the server).
 
-    docker_daemon_options:
+```yaml
+docker_daemon_options:
   storage-driver: "devicemapper"
   log-opts:
     max-size: "100m"
+```
 
 Custom `dockerd` options can be configured through this dictionary representing the json file `/etc/docker/daemon.json`.
 

defaults/main.yml

@@ -7,6 +7,7 @@ docker_packages:
   - "docker-{{ docker_edition }}-rootless-extras"
   - "containerd.io"
   - docker-buildx-plugin
+docker_packages_state: present
 docker_obsolete_packages:
   - docker
   - docker.io
@@ -14,7 +15,6 @@ docker_obsolete_packages:
   - podman-docker
   - containerd
   - runc
-docker_packages_state: present
 
 # Service options.
 docker_service_manage: true