As per the docs the following should override the image defined health check. But it fails to override the image defined health check. This is important where the image defined health check is not applicable. One such example is using the creating a MySQL cluster in that the default health check is against mysqld which is not appropriate because either ndbd or ndb_mgmd is appropriate.

This leaves the container marked as unhealthy.

Using;

healthcheck:
  test: ["NONE"]

If you use the above to launch MySQL the default health check is used, inspect output following.

            "Healthcheck": {
                "Test": [
                    "CMD-SHELL",
                    "/healthcheck.sh"
                ]
            },

Resulting in;

21b30279e77d        mysql/mysql-cluster:8.0.18                          "/entrypoint.sh mysq…"   3 minutes ago       Up 2 minutes (healthy)     1186/tcp, 2202/tcp, 3306/tcp, 33060/tcp                                  dev-mysql
0fb50981bba5        mysql/mysql-cluster:8.0.18                          "/entrypoint.sh ndbd"    3 minutes ago       Up 3 minutes (unhealthy)   1186/tcp, 2202/tcp, 3306/tcp, 33060/tcp                                  dev-mysql-ndbd-2
8746135e3f8e        mysql/mysql-cluster:8.0.18                          "/entrypoint.sh ndbd"    3 minutes ago       Up 3 minutes (unhealthy)   1186/tcp, 2202/tcp, 3306/tcp, 33060/tcp                                  dev-mysql-ndbd-1
420fb8249df8        mysql/mysql-cluster:8.0.18                          "/entrypoint.sh ndb_…"   3 minutes ago       Up 3 minutes (healthy)     1186/tcp, 2202/tcp, 3306/tcp, 33060/tcp                                  dev-mysql-mgmd

The work around is to call a stub shell which simply calls exit 0.

    healthcheck:
      test: ["CMD-SHELL", "{{ mysql_config_directory }}/healthcheck.sh"]

Resulting in;

            "Healthcheck": {
                "Test": [
                    "CMD-SHELL",
                    "/etc/cell/dev/mysql/healthcheck.sh"
                ]
            },
 And;

aaf28f87abf0        mysql/mysql-cluster:8.0.18                          "/entrypoint.sh mysq…"   3 minutes ago       Up 3 minutes (healthy)   1186/tcp, 2202/tcp, 3306/tcp, 33060/tcp                                  dev-mysql
2df7948c37fc        mysql/mysql-cluster:8.0.18                          "/entrypoint.sh ndbd"    3 minutes ago       Up 3 minutes (healthy)   1186/tcp, 2202/tcp, 3306/tcp, 33060/tcp                                  dev-mysql-ndbd-2
1a3cd97cfc80        mysql/mysql-cluster:8.0.18                          "/entrypoint.sh ndbd"    3 minutes ago       Up 3 minutes (healthy)   1186/tcp, 2202/tcp, 3306/tcp, 33060/tcp                                  dev-mysql-ndbd-1
5fea532ef20f        mysql/mysql-cluster:8.0.18                          "/entrypoint.sh ndb_…"   3 minutes ago       Up 3 minutes (healthy)   1186/tcp, 2202/tcp, 3306/tcp, 33060/tcp                                  dev-mysql-mgmd

description:
      - Command that overwrites the default C(ENTRYPOINT) of the image.
    type: list
    elements: str
  etc_hosts:
    description:
      - Dict of host-to-IP mappings, where each host name is a key in the dictionary.
        Each host name will be added to the container's C(/etc/hosts) file.
    type: dict
  exposed_ports:
    description:
      - List of additional container ports which informs Docker that the container
        listens on the specified network ports at runtime.
      - If the port is already exposed using C(EXPOSE) in a Dockerfile, it does not
        need to be exposed again.
    type: list
    elements: str
    aliases:
      - exposed
      - expose
  force_kill:
    description:
      - Use the kill command when stopping a running container.
    type: bool
    default: no
    aliases:
      - forcekill
  groups:
    description:
      - List of additional group names and/or IDs that the container process will run as.