Refactor the script a bit.

images/docker/compose-health-check

@@ -26,15 +26,22 @@ def get_project_containers_health(client, project):
     }
 
 
-def check_project_health(project, timeout):
-    """Checks if a Docker Compose project is healthy.
+def get_unhealthy_project_containers(client, project):
+    """Returns a list (could be empty) of containers that are not healthy or
+    not running (in case a health check is not set)."""
+    healths = get_project_containers_health(client, project)
+    return [x for x in healths if healths[x] not in ["healthy", "running"]]
+
+
+def wait_for_project_health(project, timeout):
+    """Wait for a Docker Compose project to be healthy.
 
     If all of the containers are healthy or running (because there's no
-    healthcheck set), return True. If any of the containers is starting (health
-    check hasn't run yet or in the grace period), sleep 10 and try again
-    (ignoring the timeout). Otherwise, if haven't passed the timeout, sleep 10
-    and try again, if over the timeout, return if all the containers are
-    healthy or running.
+    healthcheck set), return an empty list. If any of the containers are
+    starting (health check hasn't run yet or in the grace period), sleep 10 and
+    try again (ignoring the timeout). Otherwise, if the timeout hasn't passed,
+    sleep 10 and try again, if over the timeout, return a list of the
+    containers that aren't healthy or aren't running.
     """
     starttime = datetime.datetime.now()
     deadline = starttime + datetime.timedelta(seconds=timeout)
@@ -43,8 +50,8 @@ def check_project_health(project, timeout):
     while True:
         healths = get_project_containers_health(docker_client, project)
         # pylint: disable=no-else-return
-        if all(map(lambda x: x in ["healthy", "running"], healths.values())):
-            return True
+        if not get_unhealthy_project_containers(docker_client, project):
+            return []
         elif any(map(lambda x: x == "starting", healths.values())):
             time.sleep(10)
             continue
@@ -53,24 +60,26 @@ def check_project_health(project, timeout):
         else:
             time.sleep(10)
 
-    if all(map(lambda x: x in ["healthy", "running"], healths.values())):
-        return True
-    unhealthy = ", ".join(
-        [
-            f"{x.id}({x.name})"
-            for x in healths
-            if healths[x] not in ["healthy", "running"]
-        ]
-    )
-    print(f"""Containers {unhealthy} are not healthy.""")
-    return False
+    return get_project_containers_health(docker_client, project)
+
+
+def get_project_name(args):
+    """Returns the name of the Docker Compose project, or None if unable to."""
+    if args.project:
+        return args.project
+    env = dotenv.dotenv_values(dotenv_path=".env")
+    if "COMPOSE_PROJECT_NAME" in env:
+        return env["COMPOSE_PROJECT_NAME"]
+    if "COMPOSE_PROJECT_NAME" in os.environ:
+        return os.environ["COMPOSE_PROJECT_NAME"]
+    return None
 
 
 def main():
     """Main entrypoint."""
 
     epilog = (
-        "The Docker Compose project name is resolved in the following order:"  # noqa: E501
+        "The Docker Compose project name is resolved in the following order:"
         "\n1. From the command line parameter."
         "\n2. From the COMPOSE_PROJECT_NAME variable in the .env file."
         "\n3. From the COMPOSE_PROJECT_NAME environment variable."
@@ -91,21 +100,21 @@ def main():
         default=300,
     )
     args = arg_parser.parse_args()
-    if args.project:
-        project = args.project
-    else:
-        env = dotenv.dotenv_values(dotenv_path=".env")
-        if "COMPOSE_PROJECT_NAME" in env:
-            project = env["COMPOSE_PROJECT_NAME"]
-        elif "COMPOSE_PROJECT_NAME" in os.environ:
-            project = os.environ["COMPOSE_PROJECT_NAME"]
-        else:
+
+    project = get_project_name(args)
+    if project is None:
         arg_parser.error(
             "Compose project wasn't specified, the COMPOSE_PROJECT_NAME variable is missing from the environment and from the .env file."  # noqa: E501
         )
 
-    if check_project_health(project, args.timeout):
+    unhealthy = wait_for_project_health(project, args.timeout)
+
+    if not unhealthy:
+        print(f"Project {project} is healthy.")
         return 0
+    print(
+        f"""The {", ".join(map(lambda x: x.name, unhealthy))} container for project {project} are not healthy."""  # noqa: E501
+    )
     return 1