Adopt health checks for dbus-session

[vpetersson]

I attempted to add a health check for dbus-session in #174. However, since we are currently using docker-compose version 2, this will not work. To implement this health check properly, we need to upgrade to 2.4. There is as pull request for this below, so let's just wait until this has been sorted out.

The health check would look something like this:

    healthcheck:
      test: [
        "dbus-send",
        "--system",
        "--print-reply",
        "--dest=org.freedesktop.DBus /org/freedesktop/DBus org.freedesktop.DBus.ListNames"
      ]
      interval: 5m
      timeout: 10s
      retries: 5
      start_period: 30s

We might need to tweak these values a bit.

The task includes:

• Upgrade the Docker Compose version to 2.4
• Implement the above health check
• Remove dbus-wait hm-miner#44
• Remove dbus-wait hm-config#114
• Add 'depends_on' condition to the above services (including for hm-diag)

References

• Blocked by Update resin-compose-parse from 2.1.3 to 2.3.0 balena-io/balena-cli#2365
• Balena support ticket
• docker-compose fields
• health checks

[shawaj]

Need to add one for diagnostics too presumably?

[vpetersson]

Already added that.

[shawaj]

Already added that.

But it's not being checked anywhere? Need to add that to the docker compose for miner and config containers

[shawaj]

Needs to be like:

    depends_on:
      dbus-session:
        condition: service_healthy
      diagnostics:
        condition: service_healthy

[vpetersson]

You are correct. We need to add this condition too. I assumed that was implicit, but it wasn't.

[shawaj]

I think service_started is the default https://docs.docker.com/compose/compose-file/compose-file-v2/#depends_on

[vpetersson]

From balena support:

---

Victor, I'm afraid this will not work even after (any level of) support for 2.4 is added. Our Supervisors currently only understand the service_started kind of depends_on (ie. not service_healthy). We do have plans to ultimately extend support for several newer properties and features of Docker Compose but it's a complex that just hasn't been prioritised yet.

Can you briefly describe the use case you have for depending on service_healthy? We may be able to suggest workarounds for the short/mid term.

[shawaj]

@vpetersson ahh that is annoying...did they have any possible workarounds?

[vpetersson]

The current workaround is essentially what we're doing (i.e. a checker in the init script). I've requested here if the new changes will also include the service_healthy state.