Hertz 学习笔记（20）

今天学用 Prometheus 来监控服务端

使用 Prometheus 进行服务监控的示例

服务端代码如下：

/*
 * Copyright 2022 CloudWeGo Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package main

import (
	"context"
	"time"

	"github.com/cloudwego/hertz/pkg/app"
	"github.com/cloudwego/hertz/pkg/app/server"
	prometheus "github.com/hertz-contrib/monitor-prometheus"
)

func main() {
	h := server.Default(
		server.WithHostPorts("127.0.0.1:8080"),
		server.WithTracer(
			prometheus.NewServerTracer(":9091", "/hertz",
				prometheus.WithEnableGoCollector(true), // enable go runtime metric collector
			),
		),
	)

	h.GET("/metricGet", func(c context.Context, ctx *app.RequestContext) {
		ctx.String(200, "hello get")
	})

	h.POST("/metricPost", func(c context.Context, ctx *app.RequestContext) {
		time.Sleep(100 * time.Millisecond)
		ctx.String(200, "hello post")
	})

	h.Spin()
}

要跑这个代码需要先确保 docker 能用，安装和使用这里略过。然后 docker-compose.yml 配置文件如下：

version: '2'
services:
  prometheus:
    image: prom/prometheus:latest
    extra_hosts:
      - "host.docker.internal:host-gateway"
    volumes:
      - ./prometheus.yml:/etc/prometheus/prometheus.yml
      - ./alert.rules:/etc/prometheus/alert.rules
      - prometheus_data:/prometheus
    command:
      - '--config.file=/etc/prometheus/prometheus.yml'
    ports:
      - '9090:9090'
  grafana:
    image: grafana/grafana:latest
    extra_hosts:
      - "host.docker.internal:host-gateway"
    volumes:
      - grafana_data:/var/lib/grafana
    environment:
      - GF_SECURITY_ADMIN_PASSWORD=admin
    depends_on:
      - prometheus
    ports:
      - '3000:3000'
volumes:
  grafana_data: {}
  prometheus_data: {}

然后改一下 Prometheus 的配置文件 prometheus.yml：

# my global config
global:
  scrape_interval: 15s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
  evaluation_interval: 15s # Evaluate rules every 15 seconds. The default is every 1 minute.
  # scrape_timeout is set to the global default (10s).

# Alertmanager configuration
alerting:
  alertmanagers:
    - static_configs:
        - targets:
          # - alertmanager:9093

# Load rules once and periodically evaluate them according to the global 'evaluation_interval'.
rule_files:
  # - "first_rules.yml"
  # - "second_rules.yml"

# A scrape configuration containing exactly one endpoint to scrape:
# Here it's Prometheus itself.
scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: "hertz"

    # metrics_path defaults to '/monitoring'
    # scheme defaults to 'http'.
    scrape_interval: 1s
    metrics_path: /hertz
    static_configs:
      - targets: ['host.docker.internal:9091']