Fixes#5575
Now that only viz makes use of the `SelfCheck` api, merged the `healthcheck.proto` into `viz.proto`.
Also removed the "checkRPC" functionality that was used for handling multiple API responses and was only used by `SelfCheck`, because the extra complexity was not granted. Revert to use the plain vanilla "check" by just concatenating error responses.
## Success Output
```bash
$ bin/linkerd viz check
...
linkerd-viz
-----------
...
√ viz extension self-check
```
## Failure Examples
Failure when viz fails to connect to the k8s api:
```bash
$ bin/linkerd viz check
...
linkerd-viz
-----------
...
× viz extension self-check
Error calling the Kubernetes API: someerror
see https://linkerd.io/checks/#l5d-api-control-api for hints
Status check results are ×
```
Failure when viz fails to connect to Prometheus:
```bash
$ bin/linkerd viz check
...
linkerd-viz
-----------
...
× viz extension self-check
Error calling Prometheus from the control plane: someerror
see https://linkerd.io/checks/#l5d-api-control-api for hints
Status check results are ×
```
Failure when viz fails to connect to both the k8s api and Prometheus:
```bash
$ bin/linkerd viz check
...
linkerd-viz
-----------
...
× viz extension self-check
Error calling the Kubernetes API: someerror
Error calling Prometheus from the control plane: someerror
see https://linkerd.io/checks/#l5d-api-control-api for hints
Status check results are ×
```
* Protobuf changes:
- Moved `healthcheck.proto` back from viz to `proto/common` as it remains being used by the main `healthcheck.go` library (it was moved to viz by #5510).
- Extracted from `viz.proto` the IP-related types and put them in `/controller/gen/common/net` to be used by both the public and the viz APIs.
* Added chart templates for new viz linkerd-metrics-api pod
* Spin-off viz healthcheck:
- Created `viz/pkg/healthcheck/healthcheck.go` that wraps the original `pkg/healthcheck/healthcheck.go` while adding the `vizNamespace` and `vizAPIClient` fields which were removed from the core `healthcheck`. That way the core healthcheck doesn't have any dependencies on viz, and viz' healthcheck can now be used to retrieve viz api clients.
- The core and viz healthcheck libs are now abstracted out via the new `healthcheck.Runner` interface.
- Refactored the data plane checks so they don't rely on calling `ListPods`
- The checks in `viz/cmd/check.go` have been moved to `viz/pkg/healthcheck/healthcheck.go` as well, so `check.go`'s sole responsibility is dealing with command business. This command also now retrieves its viz api client through viz' healthcheck.
* Removed linkerd-controller dependency on Prometheus:
- Removed the `global.prometheusUrl` config in the core values.yml.
- Leave the Heartbeat's `-prometheus` flag hard-coded temporarily. TO-DO: have it automatically discover viz and pull Prometheus' endpoint (#5352).
* Moved observability gRPC from linkerd-controller to viz:
- Created a new gRPC server under `viz/metrics-api` moving prometheus-dependent functions out of the core gRPC server and into it (same thing for the accompaigning http server).
- Did the same for the `PublicAPIClient` (now called just `Client`) interface. The `VizAPIClient` interface disappears as it's enough to just rely on the viz `ApiClient` protobuf type.
- Moved the other files implementing the rest of the gRPC functions from `controller/api/public` to `viz/metrics-api` (`edge.go`, `stat_summary.go`, etc.).
- Also simplified some type names to avoid stuttering.
* Added linkerd-metrics-api bootstrap files. At the same time, we strip out of the public-api's `main.go` file the prometheus parameters and other no longer relevant bits.
* linkerd-web updates: it requires connecting with both the public-api and the viz api, so both addresses (and the viz namespace) are now provided as parameters to the container.
* CLI updates and other minor things:
- Changes to command files under `cli/cmd`:
- Updated `endpoints.go` according to new API interface name.
- Updated `version.go`, `dashboard` and `uninstall.go` to pull the viz namespace dynamically.
- Changes to command files under `viz/cmd`:
- `edges.go`, `routes.go`, `stat.go` and `top.go`: point to dependencies that were moved from public-api to viz.
- Other changes to have tests pass:
- Added `metrics-api` to list of docker images to build in actions workflows.
- In `bin/fmt` exclude protobuf generated files instead of entire directories because directories could contain both generated and non-generated code (case in point: `viz/metrics-api`).
* Add retry to 'tap API service is running' check
* mc check shouldn't err when viz is not available. Also properly set the log in multicluster/cmd/root.go so that it properly displays messages when --verbose is used
Alex Leong
Alejandro Pedraza