metrics/README.md

# metrics for dubbo-go

This example demonstrates the metrics usage of dubbo-go as an RPC framework. Check [Quick Start][] on our official website for detailed explanation.

## Contents

- server/main.go - is the main definition of the service, handler and rpc server
- client/main.go - is the rpc client
- proto - contains the protobuf definition of the API

## How to run

### Run server
```shell
go run ./go-server/cmd/main.go
```

test server work as expected:
```shell
curl \
    --header "Content-Type: application/json" \
    --data '{"name": "Dubbo"}' \
    http://localhost:20000/greet.GreetService/Greet
```

### Run client
```shell
go run ./go-client/cmd/main.go
```

## deploy to local
install prometheus and open prometheus config file `prometheus.yml`, write the config like this

```yaml
global:
  evaluation_interval: 15s
  scrape_interval: 15s
scrape_configs:
- job_name: dubbo-provider
  scrape_interval: 15s
  scrape_timeout: 5s
  metrics_path: /prometheus
  static_configs:
    - targets: ['localhost:9099']
- job_name: dubbo-consumer
  scrape_interval: 15s
  scrape_timeout: 5s
  metrics_path: /prometheus
  static_configs:
    - targets: ['localhost:9097']
```

install grafana and open grafana web page like `localhost:3000`

open: 【Home / Connections / Data sources】

click 【Add new data source】

select Prometheus

enter 【Prometheus server URL】 like `http://localhost:9090` and click 【Save & test】

![datasource.png](./assert/datasource.png)

open 【Home / Dashboards 】click 【New】【import】and enter 19294 click Load

![import](./assert/import.png)

if your grafana can't access internet you can open `https://grafana.com/grafana/dashboards/19294-dubbo-observability/` and click 【Download JSON】

paste the JSON

![json.png](./assert/import-json.png)

![datasource.png](./assert/import-datasource.png)

click 【Import】button and you will see the Dubbo Observability dashboard,enjoy it

![databoard](./assert/dashboard.png)

## Deploy to Kubernetes

#### kube-prometheus

install prometheus in k8s [kube-prometheus](https://github.com/prometheus-operator/kube-prometheus)

Set `prometheus-service.yaml` type to NodePort

1. add `dubboPodMoitor.yaml` to  `kube-prometheus` `manifests` dir, The content is as follows
 ```yaml
apiVersion: monitoring.coreos.com/v1
kind: PodMonitor
metadata:
  name: podmonitor
  labels:
    app: podmonitor
  namespace: monitoring
spec:
  namespaceSelector:
    matchNames:
      - dubbo-system
  selector:
    matchLabels:
      app-type: dubbo
  podMetricsEndpoints:
    - port: metrics # ref to dubbo-app port name metrics
      path: /prometheus
---
# rbac
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  namespace: dubbo-system
  name: pod-reader
rules:
  - apiGroups: [""]
    resources: ["pods"]
    verbs: ["get", "list", "watch"]

---
# rbac
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: pod-reader-binding
  namespace: dubbo-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: pod-reader
subjects:
  - kind: ServiceAccount
    name: prometheus-k8s
    namespace: monitoring
```
2. `kubectl apply -f Deployment.yaml`
3. open prometheus web page such as http://localhost:9090/targets
   ![podmonitor.png](./assert/podmonitor.png)