Add Thanos tenancy proxy for rules

[simonpasquier]

The Thanos querier deployment exposes a tenancy-aware service for
recording and alerting rules. It is exposed via a different port than
the existing tenancy-aware service for queries because it requires
different permissions to be granted.

This change modifies the console bridge to make this service available
to the console users.

cc @kyoto @vikram-raj

[vikram-raj]

Thanks @simonpasquier,

I verified the changes and in in-cluster mode and for endpoint /api/prometheus-tenancy/api/v1/rules?namespace=ns1 we get response as below as expected

{
  status: 'success',
  data: {
    groups: [
      {
        name: 'example',
        file: '/etc/thanos/rules/thanos-ruler-user-workload-rulefiles-0/ns1-example-alert.yaml',
        rules: [
          {
            name: 'VersionAlert',
            query: 'version{job="prometheus-example-app",namespace="ns1"} == 0',
            duration: 1,
            labels: {
              namespace: 'ns1',
            },
            annotations: {},
            alerts: [
              {
                labels: {
                  alertname: 'VersionAlert',
                  endpoint: 'web',
                  instance: '10.129.2.10:8080',
                  job: 'prometheus-example-app',
                  namespace: 'ns1',
                  pod: 'prometheus-example-app-57d8c46fb9-2w8fw',
                  prometheus: 'openshift-user-workload-monitoring/user-workload',
                  service: 'prometheus-example-app',
                  version: 'v0.1.0',
                },
                annotations: {},
                state: 'FIRING',
                activeAt: '2020-07-07T15:32:45.389025513Z',
                value: '0e+00',
              },
            ],
            health: 'ok',
            type: 'alerting',
          },
          {
            name: 'VersionRule',
            query: 'version{job="prometheus-example-app",namespace="ns1"}',
            labels: {
              namespace: 'ns1',
            },
            health: 'ok',
            type: 'recording',
          },
        ],
        interval: 15,
      },
    ],
  },
}

however in off-cluster i:e localhost this endpoint api/prometheus-tenancy/api/v1/rules?namespace=ns1 return cluster wide rules instead of per namespace.

[vikram-raj]

We need this service for Monitoring work for 4.6.

/cc @christianvogt @abhi-kn

[simonpasquier]

cc @paulfantom for a review from the monitoring team.

[paulfantom]

LGTM, leaving final /approve to the console team.

[paulfantom]

/lgtm

[invincibleJai]

Thanks @paulfantom , @spadgett needed your help with review

cc @vikram-raj

[invincibleJai]

/assign @spadgett

[spadgett]

/approve
/lgtm

[openshift-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: paulfantom, simonpasquier, spadgett

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