Running container is considered unhealthy

[mshero]

Proposal

The Problem

When running running the image with a custom port, the docker system considers the container as unhealthy though it is not. In fact the __admin/health endpoint returns `status: "healthy".

Expected

When running the image with a custom port the docker system considers the container as healthy.

Actual Behavior

The docker system considers the container unhealthy.

Reproduction steps

Start the WireMock image - spoiler shows expected output

$ docker run -it --rm -p 8089:8089 -e WIREMOCK_OPTIONS='--port 8089' wiremock/wiremock

██     ██ ██ ██████  ███████ ███    ███  ██████   ██████ ██   ██ 
██     ██ ██ ██   ██ ██      ████  ████ ██    ██ ██      ██  ██  
██  █  ██ ██ ██████  █████   ██ ████ ██ ██    ██ ██      █████   
██ ███ ██ ██ ██   ██ ██      ██  ██  ██ ██    ██ ██      ██  ██  
 ███ ███  ██ ██   ██ ███████ ██      ██  ██████   ██████ ██   ██ 

----------------------------------------------------------------
|               Cloud: https://wiremock.io/cloud               |
|                                                              |
|               Slack: https://slack.wiremock.org              |
----------------------------------------------------------------

version:                      3.9.1
port:                         8089
enable-browser-proxying:      false
disable-banner:               false
no-request-journal:           false
verbose:                      false

extensions:                   response-template,webhook

Check health endpoint - also here everything looks fine

$ curl -sS -X GET http://localhost:8089/__admin/health | jq
{
  "status": "healthy",
  "message": "Wiremock is ok",
  "version": "3.9.1",
  "uptimeInSeconds": 56,
  "timestamp": "2024-09-06T13:39:53.020787Z"
}

Check docker container - status states (unhealthy)

$ docker ps 
CONTAINER ID   IMAGE               COMMAND                  CREATED              STATUS                          PORTS                                        NAMES
a482d4afd42b   wiremock/wiremock   "/docker-entrypoint.…"   About a minute ago   Up About a minute (unhealthy)   8080/tcp, 8443/tcp, 0.0.0.0:8089->8089/tcp   confident_goodall

At this point one could state this doesn't look as a big issue as the container is up and running and serving as expected. The problem manifests rather when WireMock is set up utilizing docker compose.

Example docker-compose.yaml

services:
  wiremock:
    image: wiremock/wiremock
    container_name: wiremock-local
    entrypoint: [ "/docker-entrypoint.sh", "--port=8089"]
    ports:
      - "8089:8089"

And the docker compose command that fails

$ docker compose up --wait
[+] Building 0.0s (0/0)                                                                                                                                                  
[+] Running 0/1
 ⠿ Container wiremock-main  Waiting                                                                                                                                90.8s 
container wiremock-main is unhealthy

References

A brief investigation (docker inspect) of the running container pointed to the underlying problem

$ docker inspect confident_goodall
...
            "Health": {
                "Status": "unhealthy",
                "FailingStreak": 31,
                "Log": [
                    {
                        "Start": "2024-09-06T16:07:05.878727105+02:00",
                        "End": "2024-09-06T16:07:06.012145585+02:00",
                        "ExitCode": 1,
                        "Output": "  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current\n                                 Dload  Upload   Total   Spent    Left  Speed\n\r  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0\r  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0\ncurl: (7) Failed to connect to localhost port 8080 after 2 ms: Couldn't connect to server\n"
                    },
                    {
                        "Start": "2024-09-06T16:07:36.019068045+02:00",
                        "End": "2024-09-06T16:07:36.110571656+02:00",
                        "ExitCode": 1,
                        "Output": "  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current\n                                 Dload  Upload   Total   Spent    Left  Speed\n\r  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0\r  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0\ncurl: (7) Failed to connect to localhost port 8080 after 2 ms: Couldn't connect to server\n"
                    },
                    {
                        "Start": "2024-09-06T16:08:06.115316283+02:00",
                        "End": "2024-09-06T16:08:06.242779708+02:00",
                        "ExitCode": 1,
                        "Output": "  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current\n                                 Dload  Upload   Total   Spent    Left  Speed\n\r  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0\r  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0\ncurl: (7) Failed to connect to localhost port 8080 after 2 ms: Couldn't connect to server\n"
                    },
                    {
                        "Start": "2024-09-06T16:08:36.249012972+02:00",
                        "End": "2024-09-06T16:08:36.387739973+02:00",
                        "ExitCode": 1,
                        "Output": "  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current\n                                 Dload  Upload   Total   Spent    Left  Speed\n\r  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0\r  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0\ncurl: (7) Failed to connect to localhost port 8080 after 2 ms: Couldn't connect to server\n"
                    },
                    {
                        "Start": "2024-09-06T16:09:06.393761069+02:00",
                        "End": "2024-09-06T16:09:06.498217177+02:00",
                        "ExitCode": 1,
                        "Output": "  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current\n                                 Dload  Upload   Total   Spent    Left  Speed\n\r  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0\r  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0\ncurl: (7) Failed to connect to localhost port 8080 after 2 ms: Couldn't connect to server\n"
                    }
                ]
            }
...
            "Healthcheck": {
                "Test": [
                    "CMD-SHELL",
                    "curl -f http://localhost:8080/__admin/health || exit 1"
                ],
                "StartPeriod": 5000000000
            },
...

Docker engine in use

$ docker version
Client: Docker Engine - Community
 Version:           24.0.2
 API version:       1.43
 Go version:        go1.20.4
 Git commit:        cb74dfc
 Built:             Thu May 25 21:52:13 2023
 OS/Arch:           linux/amd64
 Context:           default

Server: Docker Engine - Community
 Engine:
  Version:          24.0.2
  API version:      1.43 (minimum version 1.12)
  Go version:       go1.20.4
  Git commit:       659604f
  Built:            Thu May 25 21:52:13 2023
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.6.21
  GitCommit:        3dce8eb055cbb6872793272b4f20ed16117344f8
 runc:
  Version:          1.1.7
  GitCommit:        v1.1.7-0-g860f061
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

[mshero]

Workaround

When looking for a workaround I found one in the docker documentation.
The section Overriding image defaults contains a paragraph related to health checks.

TL;DR

For simple docker run invocation one is able to override the health command like so:

$ docker run ... --health-cmd='curl -f http://localhost:8089/__admin/health || exit 1' ...

Same is possible using docker compose as follows:

services:
  wiremock:
    ...
    healthcheck:
      test: [ "CMD", "curl", "-f", "http://localhost:8089/__admin/health" ]

After adding this very line to the example docker-compose.yaml shared before the container is reported as healthy.

$ docker compose up --wait
[+] Building 0.0s (0/0)                                                                                                                                                  
[+] Running 1/1
 ✔ Container wiremock-main  Healthy

If this isn't considered a workaround but the solution to the problem, you think it could go into the Running in Docker documentation?

And, by the way, thanks for such a nice and flexible mocking service... 🙇