Linux docker emulator lacks 'curl' command

[jalbiero]

Describe the bug The linux emulator doesn't provide the curl command (or similar like wget), so it is not possible to perform a basic healtcheck (as is usual with docker compose)

Disclaimer: IMHO this is a bug, not a feature request, because a common operation with docker compose cannot be performed (unless there is an alternative way to check when CosmosDB service is ready)

To Reproduce

1. Suppose the following docker compose file (compose.yaml):

services:
  CosmosDb:
    image: mcr.microsoft.com/cosmosdb/linux/azure-cosmos-emulator
    ports:
      - 443:443
      - 8081:8081
      - 10250-10255:10250-10255
    healthcheck:
      test: ["CMD", "curl", "-f", "-k", "https://localhost:8081/_explorer/emulator.pem"]
      interval: 10s
      retries: 12
      timeout: 3s

2. Run the service and wait:

PS C:\Users\FooUser\CosmosDbTest> docker compose up --wait
[+] Running 0/1
 - Container cosmosdbtest-CosmosDb-1  Waiting        60.9s 
container cosmosdbtest-CosmosDb-1 is unhealthy

3. The container inspection reveals the problem, curl is missing:

PS C:\Users\FooUser\CosmosDbTest> docker inspect cosmosdbtest-CosmosDb-1
[
    {
        "Id": "65f4798648c3889e9e23608addf423e33d9f4a47ab2ae9512fec65658a0250e5",
        "Created": "2024-07-10T14:41:28.483636479Z",
        "Path": "/usr/local/bin/cosmos/start.sh",
        "Args": [],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 48405,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2024-07-10T14:41:39.46781182Z",
            "FinishedAt": "0001-01-01T00:00:00Z",
            "Health": {
                "Status": "unhealthy",
                "FailingStreak": 308,
                "Log": [
                    {
                        "Start": "2024-07-10T15:32:28.363369721Z",
                        "End": "2024-07-10T15:32:28.390398997Z",
                        "ExitCode": -1,
                        "Output": "OCI runtime exec failed: exec failed: unable to start container process: exec: \"curl\": executable file not found in $PATH: unknown"
                    },
                    {
                        "Start": "2024-07-10T15:32:38.391259729Z",
                        "End": "2024-07-10T15:32:38.41879366Z",
                        "ExitCode": -1,
                        "Output": "OCI runtime exec failed: exec failed: unable to start container process: exec: \"curl\": executable file not found in $PATH: unknown"
                    },
                    ...

Expected behavior If curl is provided the following is expected:

PS C:\Users\FooUser\CosmosDbTest> docker compose up --wait
[+] Running 1/1
 ✔ Container cosmosdbwrapper-CosmosDb-1  Healthy

Desktop

• OS: Windows 11 Pro

Docker Images Used

• Linux: mcr.microsoft.com/cosmosdb/linux/azure-cosmos-emulator:latest (pull date: 07/10/2024)

Docker Environment

• Docker Desktop version: 4.32.0
• Docker version: 27.0.3, build 7d4bcd8

[jrichardsz]

curl could help us to add custom health checks like Jalbiero or :

    healthcheck:
      test:  curl --insecure --fail https://localhost:8081/_explorer/index.html

[jalbiero]

I am using the following workaround, a "wrapper" image (cosmos-emulator-wrapper) that contains the curl utility:

services:
  CosmosDb:
    image: cosmos-emulator-wrapper
    build:
      dockerfile_inline: |
        FROM mcr.microsoft.com/cosmosdb/linux/azure-cosmos-emulator:latest
        RUN apt-get update && \
            DEBIAN_FRONTEND=noninteractive apt-get install -y \
            curl
    ports:
      - 443:443
      - 8081:8081
      - 10250-10255:10250-10255
    healthcheck:
      test: ["CMD", "curl", "-f", "-k", "https://localhost:8081/_explorer/emulator.pem"]
      interval: 10s
      retries: 12
      timeout: 3s