I am studying Ansible at the end of the year. When installing Docker with Ansible, I will leave a memorandum of what to do when a newer version than the target version is installed. You should be able to do the same when installing other packages using the apt module.

Conclusion

Set force to true
Set force-downgrade in dpkg_options

`main.yml`


- name: Docker | Install Docker | apt
  apt:
    name:
     - "docker-ce={{docker_ce_version}}"
     - "docker-ce-cli={{docker_ce_cli_version}}"
     - "containerd.io={{containerd_io_version}}"
    state: present
    update_cache: yes
    force: yes
    dpkg_options: force-downgrade

Execution environment

vagrant
- ubntu18.04
  - box-image:ubuntu/bionic64
  - 20201125.0.0
ansible:2.9.16

Execution result (failure)

Initially, I ran it with missing options and investigated it with an error similar to the following:

`ansible execution result`


fatal: [192.168.xx.xx]: FAILED! => {"cache_update_time": 1609061762, "cache_updated": true, "changed": false, 
"msg": "'/usr/bin/apt-get -y -o \"Dpkg::Options::=--force-confdef\" -o \"Dpkg::Options::=--force-confold\"
install 'docker-ce=5:18.09.2~3-0~ubuntu-bionic' 'docker-ce-cli=5:18.09.2~3-0~ubuntu-bionic' 'containerd.io=1.3.7-1'
' failed: E: Packages were downgraded and -y was used without --allow-downgrades.",
 "rc": 100, "stderr": "E: Packages were downgraded and -y was used without --allow-downgrades.",
 "stderr_lines": ["E: Packages were downgraded and -y was used without --allow-downgrades."],
 "stdout": "Reading package lists...
Building dependency tree...
Reading state information...
The following package was automatically installed and is no longer required:\n
docker-ce-rootless-extras
Use 'sudo apt autoremove' to remove it.
The following packages will be DOWNGRADED:
  containerd.io docker-ce docker-ce-cli
0 upgraded, 0 newly installed, 3 downgraded, 0 to remove and 10 not upgraded.",
 "stdout_lines": ["Reading package lists...", "Building dependency tree...", "Reading state information...",
 "The following package was automatically installed and is no longer required:",
 "  docker-ce-rootless-extras", "Use 'sudo apt autoremove' to remove it.",
 "The following packages will be DOWNGRADED:",
 "  containerd.io docker-ce docker-ce-cli", "0 upgraded, 0 newly installed, 3 downgraded, 0 to remove and 10 not upgraded."]}

Insufficient research

Should I uninstall it if it doesn't match the target version rather than downgrading?

reference

https://docs.ansible.com/ansible/latest/collections/ansible/builtin/apt_module.html https://stackoverflow.com/questions/56332649/is-there-a-way-to-allow-downgrades-with-apt-ansible-module

Ansible: Allow downgrade when installing Docker