Filtered services by health check state

[mbrevoort]

It would be really helpful if there was an endpoint to get an array of healthy services, in other words filtered by state:

Multiple options:
http://localhost:8500/v1/health/state/{state}/service/{service}
http://localhost:8500/v1/health/state/{state}?service={service}
http://localhost:8500/v1/catalog/service/{service}?state={state}

For example for service foo if I want just the passing nodes:
http://localhost:8500/v1/catalog/service/foo?state=passing

[
    {
        "Address": "10.199.246.104",
        "Node": "dev-use1b-pr-16-thal-cnsl-0004",
        "ServiceID": "foo",
        "ServiceName": "foo",
        "ServicePort": 8000,
        "ServiceTags": [
            "version:1.0.0"
        ]
    }
]

Note, in this case I don't care to receive the check details (payload with Checkid, etc.) but rather the services themselves.

Happy to do the work and pull request if we can agree on the API.

[armon]

I think this is a great idea, we can use it for the DNS internally as well, since it doesn't really care about the checks. I don't want to overload the existing endpoints, and it should definitely be in the health system not the catalog.

Maybe we add a new endpoint, "/v1/health/passing/"? Not sure how I feel about "passing", but it's better than "healthy".

[mitchellh]

@armon I think a GET parameter to /catalog/service/foo would be easiest, as was originally suggested, since its just a filter on the same operation.

[armon]

None of the catalog endpoints currently incorporate any of the health check data. I think it would be a strange deviation from the existing separation.

[mitchellh]

Ah I see what you're saying. What about a filter parameter on /health/service/foo then?

[armon]

I still think it is odd if a filter parameter on an endpoint changes the format of the result. I think @mbrevoort does not want the various check information to even be returned.

[mbrevoort]

The check data could come along for the ride, but for my use case I definitely need the service data.
It would also be fine to get all of the services entries, healthy and not healthy, with service data if it was very easy to iterate over without having to correlate two parts of the document.

[armon]

In that case, I agree with @mitchellh. We can do this with a filter flag.