feat: samples for k8s probe

README.md

@@ -36,7 +36,9 @@ Please refer to [HOWTO.md](HOWTO.md) for detailed instructions on running the sa
   * `service_discovery/service`: Java/Go interoperability with Nacos using application-level service discovery (Dubbo3 model).
 * `llm`: Example of integrating Large Language Models (LLMs) with Dubbo-go.
 * `logger`: Logging examples for Dubbo-go applications.
-* `metrics`: Shows how to collect and expose metrics from Dubbo-go services, supporting both Prometheus Push and Pull modes. Also includes the `pgw-cleaner` tool for cleaning zombie metrics in Push mode.
+* `metrics`: Observability-related samples.
+  * `metrics/prometheus_grafana`: Shows how to collect and expose metrics from Dubbo-go services, supporting both Prometheus Push and Pull modes. Also includes the `pgw-cleaner` tool for cleaning zombie metrics in Push mode.
+  * `metrics/probe`: Demonstrates Dubbo-go Kubernetes probe endpoints (`/live`, `/ready`, `/startup`) and deployment usage.
 * `mesh`: Proxy-based service mesh example showing how to deploy Dubbo-go services with Envoy on Kubernetes.
 * `online_boutique`: Microservices “online boutique” demo built with Dubbo-go.
 * `otel/tracing`: Distributed tracing examples using OpenTelemetry.

README_CN.md

@@ -36,7 +36,9 @@
   * `service_discovery/service`：基于 Nacos 的应用级服务发现（Dubbo3 模型）Java/Go 互操作示例。
 * `llm`：将大模型（LLM）集成到 Dubbo-go 中的示例。
 * `logger`：Dubbo-go 应用的日志使用示例。
-* `metrics`：展示如何采集并暴露 Dubbo-go 服务的指标，支持 Prometheus Push 和 Pull 两种模式；同时包含用于清理 Push 模式僵尸指标的 `pgw-cleaner` 工具。
+* `metrics`：可观测性相关示例。
+  * `metrics/prometheus_grafana`：展示如何采集并暴露 Dubbo-go 服务指标，支持 Prometheus Push 和 Pull 两种模式；同时包含用于清理 Push 模式僵尸指标的 `pgw-cleaner` 工具。
+  * `metrics/probe`：演示 Dubbo-go 在 Kubernetes 场景下的探针端点（`/live`、`/ready`、`/startup`）及部署方式。
 * `mesh`：基于代理的服务网格示例，展示如何在 Kubernetes 上结合 Envoy 部署 Dubbo-go 服务。
 * `online_boutique`：基于 Dubbo-go 构建的微服务 “在线商城” 演示项目。
 * `otel/tracing`：使用 OpenTelemetry 的分布式链路追踪示例。

metrics/probe/README.md

@@ -0,0 +1,166 @@
+
+# Dubbo-Go Kubernetes Probe Sample
+
+English | [中文](README_CN.md)
+
+This example demonstrates how to integrate **Kubernetes liveness, readiness, and startup probes** with a Dubbo-Go Triple service.
+
+It showcases how to expose dedicated probe endpoints and how Kubernetes reacts during application startup and warm-up.
+
+
+## Project Layout
+
+```
+metrics/probe/
+├── go-client/
+│   └── cmd/main.go        # Integration checker for ports/probes/RPC
+├── go-server/
+│   ├── cmd/main.go        # Application entrypoint
+│   ├── build.sh           # Docker build script
+│   └── Dockerfile         # Container image definition
+└── deploy/
+    └── server-deployment.yml  # Kubernetes deployment
+```
+
+
+## Default Configuration
+
+| Item                | Value                         |
+| ------------------- | ----------------------------- |
+| Triple service port | `20000`                       |
+| Probe HTTP port     | `22222`                       |
+| Probe endpoints     | `/live`, `/ready`, `/startup` |
+| Client target       | `tri://127.0.0.1:20000`       |
+
+### Probe Semantics
+
+* `GET /live`
+  Indicates whether the process is alive.
+
+* `GET /ready`
+  Indicates whether the service is ready to receive traffic.
+
+* `GET /startup`
+  Indicates whether the application startup phase has completed.
+
+
+## Run Locally
+
+### 1️Start the server
+
+```bash
+go run ./metrics/probe/go-server/cmd/main.go
+```
+
+### 2️Run the go-client integration checks
+
+```bash
+go run ./metrics/probe/go-client/cmd/main.go
+```
+
+The `go-client` validates:
+
+* Triple port `20000` is reachable.
+* Probe port `22222` is reachable.
+* `/live` returns `200`.
+* `/ready` and `/startup` eventually return `200` after warm-up.
+* One `Greet` RPC call succeeds.
+
+### 3️Monitor probe endpoints
+
+```bash
+watch -n 1 '
+for p in live ready startup; do
+  url="http://127.0.0.1:22222/$p"
+
+  body=$(curl -sS --max-time 2 "$url" 2>&1)
+  code=$(curl -s -o /dev/null --max-time 2 -w "%{http_code}" "$url" 2>/dev/null)
+
+  printf "%-8s [%s] %s\n" "$p" "$code" "$body"
+done
+'
+```
+
+### Expected Behavior
+
+| Phase                | /live | /ready | /startup |
+| -------------------- | ----- | ------ | -------- |
+| Process started      | 200   | 503    | 503      |
+| During warm-up       | 200   | 503    | 503      |
+| After warm-up (~15s) | 200   | 200    | 200      |
+
+
+## Kubernetes Probe Configuration
+
+Example probe configuration:
+
+```yaml
+livenessProbe:
+  httpGet:
+    path: /live
+    port: 22222
+
+readinessProbe:
+  httpGet:
+    path: /ready
+    port: 22222
+
+startupProbe:
+  httpGet:
+    path: /startup
+    port: 22222
+```
+
+
+## Run on Kubernetes
+
+### Build the image
+
+From the repository root:
+
+```bash
+./metrics/probe/go-server/build.sh
+```
+
+
+### Load image into local cluster (if needed)
+
+For example, with Minikube:
+
+```bash
+minikube image load dubbo-go-probe-server:latest
+```
+
+
+### Deploy to Kubernetes
+
+```bash
+kubectl apply -f metrics/probe/deploy/server-deployment.yml
+kubectl rollout status deploy/dubbo-go-probe-server
+kubectl get pod -l app=dubbo-go-probe-server
+```
+
+
+### Inspect probe status
+
+```bash
+kubectl describe pod -l app=dubbo-go-probe-server
+```
+
+### Expected Kubernetes Behavior
+
+* Immediately after deployment:
+
+  * `Ready` = `False`
+  * `ContainersReady` = `False`
+
+* After ~15 seconds (warm-up completed):
+
+  * `Ready` = `True`
+  * `ContainersReady` = `True`
+
+This demonstrates proper separation of:
+
+* Process liveness
+* Service readiness
+* Startup lifecycle completion

metrics/probe/README_CN.md

@@ -0,0 +1,177 @@
+
+# Dubbo-Go Kubernetes 探针示例
+
+[English](README.md) | 中文
+
+
+本示例演示如何在 Dubbo-Go Triple 服务中集成 **Kubernetes 的 liveness、readiness 和 startup 探针**。
+
+通过暴露独立的探针端点，可以清晰地观察应用启动、预热以及就绪阶段在 Kubernetes 中的行为。
+
+
+## 项目结构
+
+```
+metrics/probe/
+├── go-client/
+│   └── cmd/main.go              # 集成测试客户端（端口/探针/RPC 校验）
+├── go-server/
+│   ├── cmd/main.go              # 程序入口
+│   ├── build.sh                 # Docker 构建脚本
+│   └── Dockerfile               # 镜像定义文件
+└── deploy/
+    └── server-deployment.yml    # Kubernetes 部署文件
+```
+
+
+## 默认配置
+
+| 项目          | 默认值                           |
+| ----------- | ----------------------------- |
+| Triple 服务端口 | `20000`                       |
+| 探针 HTTP 端口  | `22222`                       |
+| 探针路径        | `/live`, `/ready`, `/startup` |
+| 客户端目标地址     | `tri://127.0.0.1:20000`       |
+
+
+## 探针语义说明
+
+* `GET /live`
+  表示进程是否存活（进程级健康检查）。
+
+* `GET /ready`
+  表示服务是否已准备好接收流量。
+
+* `GET /startup`
+  表示应用是否完成启动阶段。
+
+
+## 本地运行
+
+### 启动服务
+
+```bash
+go run ./metrics/probe/go-server/cmd/main.go
+```
+
+### 运行 go-client 做集成检查
+
+```bash
+go run ./metrics/probe/go-client/cmd/main.go
+```
+
+`go-client` 会依次检查：
+
+* Triple 端口 `20000` 可连接。
+* 探针端口 `22222` 可连接。
+* `/live` 返回 `200`。
+* `/ready`、`/startup` 在预热完成后返回 `200`。
+* 发起一次 `Greet` RPC，确认 Triple 服务可用。
+
+
+### 观察探针状态
+
+```bash
+watch -n 1 '
+for p in live ready startup; do
+  url="http://127.0.0.1:22222/$p"
+
+  body=$(curl -sS --max-time 2 "$url" 2>&1)
+  code=$(curl -s -o /dev/null --max-time 2 -w "%{http_code}" "$url" 2>/dev/null)
+
+  printf "%-8s [%s] %s\n" "$p" "$code" "$body"
+done
+'
+```
+
+
+### 预期行为
+
+| 阶段           | /live | /ready | /startup |
+| ------------ | ----- | ------ | -------- |
+| 进程刚启动        | 200   | 503    | 503      |
+| 预热阶段         | 200   | 503    | 503      |
+| 预热完成（约 15 秒） | 200   | 200    | 200      |
+
+说明：
+
+* `/live` 只要进程未崩溃就返回 200。
+* `/ready` 与 `/startup` 在应用完成预热前返回 503。
+* 预热完成后，三个端点均返回 200。
+
+
+## Kubernetes 探针配置示例
+
+```yaml
+livenessProbe:
+  httpGet:
+    path: /live
+    port: 22222
+
+readinessProbe:
+  httpGet:
+    path: /ready
+    port: 22222
+
+startupProbe:
+  httpGet:
+    path: /startup
+    port: 22222
+```
+
+
+## 在 Kubernetes 中运行
+
+### 构建镜像
+
+在仓库根目录执行：
+
+```bash
+./metrics/probe/go-server/build.sh
+```
+
+
+### 将镜像加载到本地集群
+
+例如使用 Minikube：
+
+```bash
+minikube image load dubbo-go-probe-server:latest
+```
+
+
+### 部署到 Kubernetes
+
+```bash
+kubectl apply -f metrics/probe/deploy/server-deployment.yml
+kubectl rollout status deploy/dubbo-go-probe-server
+kubectl get pod -l app=dubbo-go-probe-server
+```
+
+
+### 查看探针状态
+
+```bash
+kubectl describe pod -l app=dubbo-go-probe-server
+```
+
+
+### 预期 Kubernetes 行为
+
+* 刚部署时：
+
+  * `Ready` = `False`
+  * `ContainersReady` = `False`
+
+* 约 15 秒后（预热完成）：
+
+  * `Ready` = `True`
+  * `ContainersReady` = `True`
+
+这体现了：
+
+* 进程存活检查（Liveness）
+* 服务可用性检查（Readiness）
+* 启动阶段控制（Startup）
+
+三者的职责分离。