Implement SMI metrics API server

[nojnhuh]

Please describe the Improvement and/or Feature Request

Add an implementation for OSM to the SMI metrics API server.

Scope (please mark with X where applicable)

• New Functionality [X]
• Install [ ]
• SMI Traffic Access Policy [ ]
• SMI Traffic Specs Policy [ ]
• SMI Traffic Split Policy [ ]
• Permissive Traffic Policy [ ]
• Ingress [ ]
• Egress [ ]
• Envoy Control Plane [ ]
• CLI Tool [ ]
• Metrics [X]
• Certificate Management [ ]
• Sidecar Injection [ ]
• Logging [ ]
• Debugging [ ]
• Tests [ ]
• CI System [ ]
• Project Release [ ]

Possible use cases

[nojnhuh]

This work is basically complete. Only waiting to merge the changes required by #984 once upstream Envoy supports WASM filters. Code is on my fork: https://github.com/nojnhuh/smi-metrics/tree/openservicemesh

[nojnhuh]

Reopening until this is merged.

[nojnhuh]

PR open: servicemeshinterface/smi-metrics#77

[michelleN]

I think we should create a slim osm-metrics chart in the OSM repo under charts/ and allow folks to install it via the osm CLI now that envoy has WASM support cc/ @nojnhuh @nojnhuh

What do ya'll think?

[nojnhuh]

What would be in that chart exactly? It seems like the most straightforward approach would be to merge OSM support into smi-metrics upstream, then make the smi-metrics chart an optional dependency of the osm chart so it could be installed with the CLI by flipping a value. I'm not seeing why we would need a separate OSM-specific chart.

[michelleN]

Does the SMI metrics chart get published to a chart repository somewhere? We'd need to reference a repository URL in the dependencies section of OSM's chart.yaml to go the optional dependency route you suggest (which makes sense).

[nojnhuh]

I don't see where a Helm repo is hosting that chart. The GitHub releases do have the .tgz attached, but it doesn't seem like Helm lets you refer to charts just by a URL.

[snehachhabria]

@nojnhuh please could you share your status on this issue? Looks like you did some work here, is it complete? If there is no more action, please could you close the issue.

[nojnhuh]

@snehachhabria There aren't any more changes we need to make to OSM for this. I planned to keep this issue open until the upstream PR I linked above is merged but I'm fine if we want to close it.

[github-actions]

This issue will be closed due to a long period of inactivity. If you would like this issue to remain open then please comment or update.

[github-actions]

Issue closed due to inactivity.