[BUG]When accessing imported Harvester in Rancher, Grafana metrics don't work correctly

[DaiYuzeng]

Describe the bug

To Reproduce
Steps to reproduce the behavior:
Preparation:

1. Go to Rancher.
2. Go to import existing Harvester cluster.
3. Access Harvester cluster.
4. Go to Harvester Dashboard page.
5. Grafana metrics display page not found

Expected behavior

The grafana metrics of the imported Harvester cluster should be displayed.

Support bundle

Environment

• Harvester ISO version:
• Underlying Infrastructure (e.g. Baremetal with Dell PowerEdge R630):

Additional context
Add any other context about the problem here.

[w13915984028]

The appSubUrl changes from 100.1.1+up19.0.3 to 102.0.0+up40.1.2 to 102.0.1+up40.1.2

/go/src/github.com/rancher/charts/charts/rancher-monitoring/100.1.1+up19.0.3$ 
charts/grafana/templates/nginx-config.yaml:          

         sub_filter '"appSubUrl":""' '"appSubUrl":"."';

/go/src/github.com/rancher/charts/charts/rancher-monitoring/102.0.0+up40.1.2$
charts/grafana/templates/nginx-config.yaml:          

         sub_filter '"appSubUrl":""' '"appSubUrl":"/k8s/clusters/{{ .Values.global.cattle.clusterId }}/api/v1/namespaces/{{ template "grafana.namespace" . }}/services/http:{{ template "grafana.fullname" . }}:{{ .Values.service.port }}/proxy"';

/go/src/github.com/rancher/charts/charts/rancher-monitoring/102.0.1+up40.1.2$ 
charts/grafana/templates/nginx-config.yaml:          

         {{- if eq .Values.global.cattle.clusterId "local" -}}
         sub_filter '"appSubUrl":""' '"appSubUrl":"/api/v1/namespaces/{{ template "grafana.namespace" . }}/services/http:{{ template "grafana.fullname" . }}:{{ .Values.service.port }}/proxy"';
         {{- else -}}
         sub_filter '"appSubUrl":""' '"appSubUrl":"/k8s/clusters/{{ .Values.global.cattle.clusterId }}/api/v1/namespaces/{{ template "grafana.namespace" . }}/services/http:{{ template "grafana.fullname" . }}:{{ .Values.service.port }}/proxy"';
         {{- end -}}

The previous issue #3780 and PR harvester/harvester-installer#492. Can work for local mode, but not for multi-cluster mode.

[w13915984028]

But there is a limitation:

The Values.global.cattle.clusterId will decide the value of appSubUrl in a configMap, one cluster can only have one role.

This is OK, when the chart is installed in an Rancher downstream cluster.

But it does not work well for Harvester.

When Harvester is accessed directly, the role is local.

When Harvester is imported into Rancher and accessed from Rancher , the role is a cluster, named like c-m-75b2hnlw.

The UI needs to deal with those 2 scenarios.

The backend fix harvester/harvester-installer#512, is utilizing the nginx customization:.

[w13915984028]

@WuJun2016 @DaiYuzeng

With the fix, there is still one issue, if we click grafana from Rancher->Harvester, the newly opened window, has no Referer field, thus the backend does not know where it comes from. Please take a look, if UI can add this field when click the link.

When we refresh the Harvester dashboard, there always has an Referer on grafana related request.

[harvesterhci-io-github-bot]

Pre Ready-For-Testing Checklist

• [ ] If labeled: require/HEP Has the Harvester Enhancement Proposal PR submitted?
  The HEP PR is at:

• Where is the reproduce steps/test steps documented?
  The reproduce steps/test steps are at: fix grafana dashboard 404 issue harvester-installer#512 (comment)

• [ ] Is there a workaround for the issue? If so, where is it documented?
  The workaround is at:

• Have the backend code been merged (harvester, harvester-installer, etc) (including backport-needed/*)?
  The PR is at: fix grafana dashboard 404 issue harvester-installer#512 (comment)

  • Does the PR include the explanation for the fix or the feature?

  • Does the PR include deployment change (YAML/Chart)? If so, where are the PRs for both YAML file and Chart?
    The PR for the YAML change is at:
    The PR for the chart change is at:

• If labeled: area/ui Has the UI issue filed or ready to be merged?
  The UI issue/PR is at:

• HARVESTER: keep the param referer on the newly opened grafana page. dashboard#792
• HARVESTER: keep the param referer on the newly opened grafana page. rancher/dashboard#9133

• [ ] If labeled: require/doc, require/knowledge-base Has the necessary document PR submitted or merged?
  The documentation/KB PR is at:

• If NOT labeled: not-require/test-plan Has the e2e test plan been merged? Have QAs agreed on the automation test case? If only test case skeleton w/o implementation, have you created an implementation issue?

  • The automation skeleton PR is at:
  • The automation test case PR is at:

• If the fix introduces the code for backward compatibility Has a separate issue been filed with the label release/obsolete-compatibility?
  The compatibility issue is filed at:

[noahgildersleeve]

Tested in Harvester master-173b0824-head and Rancher v2.7.5-rc5 with single node Docker instance. Verified that Grafana was showing up on both dashboard and in Grafana dashboard.