Add liveness and/or readiness probes to dialog

[DougReeder]

Is your feature request related to a problem? Please describe.
There's currently no monitoring of whether dialog is healthy

Describe the solution you'd like
A liveness probe would restart dialog if it hung. A readiness probe would allow a clear error status before dialog was available.

Describe alternatives you've considered
The old healthcheck endpoint was hacky and not tied to the actual server, and was deleted when HCCE was put together.

Additional context
Liveness and readiness probes are best practice for Kubernetes.

A good endpoint to use is listed in Hubs-Foundation/dialog#61

[HussainAther]

Hey, I'm happy to take a look at this.

I can see the issue references a candidate endpoint in Hubs-Foundation/dialog#61. Before I get involved or begin on this , I'd like to ask if there is a preferred deployment/service manifest in hubs-cloud where you’d want these probes added first, and are there any existing timing expectations for startup/readiness that I should preserve?

[DougReeder]

I'd like to ask if there is a preferred deployment/service manifest in hubs-cloud where you’d want these probes added first, and are there any existing timing expectations for startup/readiness that I should preserve?

community-edition/generate_script/hcce.yam is where the probes would go, in the dialog deployment.

I'm not sure we know what timing to expect for the readiness probe.

For liveness, we'd ideally like to use something that clearly indicates a problem, such as memory usage an order of magnitude higher than normal. Realistically, repeatedly failing a a cheap HTTP request is adequate.

[HussainAther]

Ty, so this I think this helps.

The readiness nd liveness probes that are used in the dialog deployment in community-edition/generate_script/hcce.yam, are using the endpoint referenced from Hubs-Foundation/dialog#61 as the starting point.

Since readiness timing is still a bit uncertain, I’ll keep the initial values conservative and aim for something easy to adjust in follow-up if needed.