Docker Swarm: delete unused configs

docker_swarm_config_cleanup.py

import docker

client = docker.client.from_env()

def get_configs_for_service(service):
    return [
        *get_configs_from_current_spec(service),
        *get_configs_from_previous_spec(service)
    ]

def get_configs_from_current_spec(service):
    try:
        return [client.configs.get(config_id=config["ConfigID"]) for config in service.attrs["Spec"]["TaskTemplate"]["ContainerSpec"]["Configs"]]
    except KeyError:
        return list()

def get_configs_from_previous_spec(service):
    try:
        return [client.configs.get(config_id=config["ConfigID"]) for config in service.attrs["PreviousSpec"]["TaskTemplate"]["ContainerSpec"]["Configs"]]
    except KeyError:
        return list()

def main():
    confs_to_remove = client.configs.list()
    confs_to_keep = list()
    for service in client.services.list():
        confs_to_keep.extend(get_configs_for_service(service))

    for conf in confs_to_keep:
        try:
            confs_to_remove.remove(conf)
        except ValueError:
            pass

    print(f"{len(confs_to_remove)} configs to remove")

    for conf in confs_to_remove:
        print(conf.short_id)
        conf.remove()

if __name__ == "__main__":
    main()

Deletes unused Docker Swarm configs, while preserving configs that might be necessary for rollbacks.

Requires: python3 and the docker python SDK.