Docker swarm stack file healthcheck command does not work as expected

Question

I faced with the following issue:

the container is running with the following healthcheck config (test is in question)

    healthcheck:
      test: ["CMD-SHELL", "curl -s -X GET http://127.0.0.1:5000/actuator/health", "|", "grep 'UP'"]
      interval: 30s
      timeout: 3s
      retries: 3
      start_period: 10s

in runtime I see that only the first part of the healthcheck test command (curl -s -X GET http://127.0.0.1:5000/actuator/health) is considered. The endpoint answers with status: Down, but healthcheck is passed - "Status": "healthy":

docker inspect 1f074dc72c6d | grep -i -A 10 health
            "Health": {
                "Status": "healthy",
                "FailingStreak": 0,
                "Log": [
                    {
                        "Start": "2019-12-10T11:37:46.215783033Z",
                        "End": "2019-12-10T11:37:46.315844469Z",
                        "ExitCode": 0,
                        "Output": "{\"status\": \"DOWN\"}"
                    },
                    {
                        "Start": "2019-12-10T11:38:16.346253717Z",
--
            "Healthcheck": {
                "Test": [
                    "CMD-SHELL",
                    "curl -s -X GET http://127.0.0.1:5000/actuator/health",
                    "|",
                    "grep 'UP'"
                ],
                "Interval": 30000000000,
                "Timeout": 3000000000,
                "StartPeriod": 10000000000,
                "Retries": 3

Answer 1

CMD-SHELL takes one argument, the string gets passed to a shell that handles parsing the string:

test: ["CMD-SHELL", "curl -s -X GET http://127.0.0.1:5000/actuator/health | grep 'UP'"]