WIP: proper healthchecks support

[muayyad-alsadi]

continue on #22

https://docs.docker.com/compose/compose-file/#healthcheck
https://docs.docker.com/engine/reference/builder/#healthcheck
https://docs.docker.com/engine/reference/run/#healthcheck

and

containers/podman#3507

[stefanb2]

Sorry for my bad Pythonese. Your solution using cmd_quote is much better.

I tested your latest change and it doesn't handle all cases correctly. Please see the latest commit I pushed to my fork. Do you want a PR for it or can you cherry-pick it?

[muayyad-alsadi]

if my comments in podman are taken in consideration
containers/podman#3507 (comment)

the code should be like

        if is_str(healthcheck_test):
            # podman does not add shell to handle command with whitespace
            args.extend(['--healthcheck-command', healthcheck_test])
        elif is_list(healthcheck_test):
            # If it’s a list, first item is either NONE, CMD or CMD-SHELL.
            healthcheck_type = healthcheck_test.pop(0)
            if healthcheck_type == 'NONE':
                args.append("--no-healthcheck")
            elif healthcheck_type == 'CMD':
                args.extend(['--healthcheck-command', json.dumps(healthcheck_test)])
            elif healthcheck_type == 'CMD-SHELL':
                if len(healthcheck_test)!=1:
                    raise ValueError("'CMD_SHELL' takes a single string after it")
                args.extend(['--healthcheck-command', healthcheck_test])

[chpio]

Don't know if that error has anything with this:

File "/home/thomas/bin/podman-compose", line 506
    args.extend(['--healthcheck-command', '/bin/sh -c {}'.format(cmd_quote(healthcheck_test[0])]))
                                                                                               ^
SyntaxError: invalid syntax

on current master (e21932e)

[stefanb2]

@chpio I noticed that too and fixed it in my patch stefanb2/podman-compose@d1583d5b

[muayyad-alsadi]

@chpio I've fixed the typo, please tell me if it fixed the issue

@stefanb2 I did not like quoting the whole thing as you did

args.extend(['--healthcheck-command', cmd_quote('/bin/sh -c {}'.format(cmd_quote(healthcheck_test)))])
args.extend(['--healthcheck-command', cmd_quote(' '.join([cmd_quote(i) for i in healthcheck_test])
args.extend(['--healthcheck-command', cmd_quote('/bin/sh -c {}'.format(cmd_quote(healthcheck_test[0])))])

because when we pass arrays ["something", "otherthing"] the string is passed as is, no need for extra escaping.

anyway, I'm following podman ticket to see what they will do. I hope they solve it in a way I can pass a string or of a list json.dumps(ls)

it's not compose job to work with shell, compose does not even know which shell to use (bash, sh, or zsh), if I want to inspect the image to know the shell, I might need to pull it first, but I can't pull it every time if it's already pulled. (it's a lot of job to do in compose)

on the other hand, podman knows.

[stefanb2]

@muayyad-alsadi oops I just looked at the generated command lines and missed the fact that your are not passing them to the shell. Just forget my change then.

[chpio]

@chpio I've fixed the typo, please tell me if it fixed the issue

yeah, thank you for that

[davidjayb]

I am seeing an error here:

Traceback (most recent call last):
  File "/opt/homebrew/bin/podman-compose", line 33, in <module>
    sys.exit(load_entry_point('podman-compose==1.0.6', 'console_scripts', 'podman-compose')())
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/podman-compose/1.0.6/libexec/lib/python3.11/site-packages/podman_compose.py", line 2941, in main
    podman_compose.run()
  File "/opt/homebrew/Cellar/podman-compose/1.0.6/libexec/lib/python3.11/site-packages/podman_compose.py", line 1423, in run
    cmd(self, args)
  File "/opt/homebrew/Cellar/podman-compose/1.0.6/libexec/lib/python3.11/site-packages/podman_compose.py", line 1754, in wrapped
    return func(*args, **kw)
           ^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/podman-compose/1.0.6/libexec/lib/python3.11/site-packages/podman_compose.py", line 2067, in compose_up
    podman_args = container_to_args(compose, cnt, detached=args.detach)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/podman-compose/1.0.6/libexec/lib/python3.11/site-packages/podman_compose.py", line 999, in container_to_args
    raise ValueError("'CMD_SHELL' takes a single string after it")
ValueError: 'CMD_SHELL' takes a single string after it

The health check in my compose file:

healthcheck:
      test: ["CMD-SHELL", "pg_isready", "-U", "$PGUSER", "-d", "$PGDATABASE"]

I was able to get around this by using CMD and switching the $PGUSER and $PGDATABASE strings to reference variables in the compose file. However, it would be nice to have this fixed.

[x-user]

Healthcheck not working on podman-compose (not tested on docker) if /bin/sh not available in container even when using CMD in heathcheck.test (reproduction).

$ podman version 
Client:       Podman Engine
Version:      4.9.0
API Version:  4.9.0
Go Version:   go1.21.6
Built:        Wed Jan 24 13:07:27 2024
OS/Arch:      linux/amd64

services:
  test:
    build:
      context: .
    container_name: healthcheck_test
    healthcheck:
      test: [
        "CMD",
        "/healthcheck",
        "http://localhost:8080/ping"
      ]
      interval: 5s
      timeout: 5s
      retries: 5

podman inspect --format "{{json .State.Health }}" healthcheck_test | jq
{
  "Status": "unhealthy",
  "FailingStreak": 18,
  "Log": [
    {
      "Start": "2024-02-15T10:34:44.046709663+03:00",
      "End": "2024-02-15T10:34:44.131872722+03:00",
      "ExitCode": 1,
      "Output": ""
    },