chore(): add cn pod scrape job (#15)

## What type of PR is this?

* [ ] Feature
* [x] BUG
* [ ] Alerts
* [ ] Improvement
* [ ] Documentation
* [ ] Test and CI

## Which issue(s) this PR related:

issue # [#2806](https://github.com/matrixorigin/MO-Cloud/issues/2806)

If this is a PR for adding Alert, please finish the workround below :)

## What this PR does / why we need it:

添加 Prometheus scrape job 专门采集 cn pods

Author: EZ4BRUCE

charts/mo-ob-opensource/Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v2
 name: mo-ob-opensource
 description: mo-ob-opensource's Helm chart for Kubernetes
 type: application
-version: 1.0.2-beta
+version: 1.0.3-alpha
 appVersion: 0.9.0
 dependencies:
 - condition: kube-prometheus-stack.enabled

charts/mo-ob-opensource/values.yaml

@@ -532,6 +532,32 @@ kube-prometheus-stack:
             - action: replace
               source_labels: [__meta_kubernetes_pod_name]
               target_label: pod
+        - job_name: "matrixone-cn-pods"
+          honor_labels: true
+          kubernetes_sd_configs:
+            - role: pod
+          relabel_configs:
+            - source_labels: [__meta_kubernetes_pod_labelpresent_matrixorigin_io_component]
+              action: keep
+              regex: true
+            - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_scrape]
+              action: keep
+              regex: "true"
+            - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_path]
+              action: replace
+              target_label: __metrics_path__
+              regex: (.+)
+            - source_labels: [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]
+              action: replace
+              target_label: __address__
+              regex: (.+?)(?::\d+)?;(\d+)
+              replacement: $1:$2
+            - action: labelmap
+              regex: __meta_kubernetes_pod_label_(.+)
+            - source_labels: [__meta_kubernetes_pod_name]
+              action: replace
+              target_label: pod
+
       alertingEndpoints:
         - name: "mo-ob-alertmanager"
           # 如果跨ns，需要修改