容器云平台监控告警体系——golang应用接入prometheus(代码片段)

// prometheus 包是 prometheus/client_golang 的核心包
go get github.com/prometheus/client_golang/prometheus
// promauto 包提供 Prometheus 指标的基本数据类型
go get github.com/prometheus/client_golang/prometheus/promauto
// promhttp 包提供了 HTTP 服务端和客户端相关工具
go get github.com/prometheus/client_golang/prometheus/promhttp

package main


import (
        "net/http"
        "github.com/prometheus/client_golang/prometheus/promhttp"
)


func main() 
        http.Handle("/metrics", promhttp.Handler())
        http.ListenAndServe(":8080", nil)

go run main.go

# HELP go_gc_duration_seconds A summary of the pause duration of garbage collection cycles.
# TYPE go_gc_duration_seconds summary
go_gc_duration_secondsquantile="0" 0
go_gc_duration_secondsquantile="0.25" 0
go_gc_duration_secondsquantile="0.5" 0
go_gc_duration_secondsquantile="0.75" 0
go_gc_duration_secondsquantile="1" 0
go_gc_duration_seconds_sum 0
go_gc_duration_seconds_count 0
# HELP go_goroutines Number of goroutines that currently exist.
# TYPE go_goroutines gauge
go_goroutines 8
# HELP go_info Information about the Go environment.
# TYPE go_info gauge
go_infoversion="go1.16.12" 1
# HELP go_memstats_alloc_bytes Number of bytes allocated and still in use.
# TYPE go_memstats_alloc_bytes gauge
go_memstats_alloc_bytes 645800
# HELP go_memstats_alloc_bytes_total Total number of bytes allocated, even if freed.
# TYPE go_memstats_alloc_bytes_total counter
go_memstats_alloc_bytes_total 645800
# HELP go_memstats_buck_hash_sys_bytes Number of bytes used by the profiling bucket hash table.
# TYPE go_memstats_buck_hash_sys_bytes gauge
go_memstats_buck_hash_sys_bytes 4086
# HELP go_memstats_frees_total Total number of frees.
# TYPE go_memstats_frees_total counter
go_memstats_frees_total 137
# HELP go_memstats_gc_cpu_fraction The fraction of this program\'s available CPU time used by the GC since the program started.
# TYPE go_memstats_gc_cpu_fraction gauge
go_memstats_gc_cpu_fraction 0
# HELP go_memstats_gc_sys_bytes Number of bytes used for garbage collection system metadata.
# TYPE go_memstats_gc_sys_bytes gauge
go_memstats_gc_sys_bytes 3.986816e+06
# HELP go_memstats_heap_alloc_bytes Number of heap bytes allocated and still in use.
# TYPE go_memstats_heap_alloc_bytes gauge
go_memstats_heap_alloc_bytes 645800
# HELP go_memstats_heap_idle_bytes Number of heap bytes waiting to be used.
# TYPE go_memstats_heap_idle_bytes gauge
go_memstats_heap_idle_bytes 6.5011712e+07
# HELP go_memstats_heap_inuse_bytes Number of heap bytes that are in use.
# TYPE go_memstats_heap_inuse_bytes gauge
go_memstats_heap_inuse_bytes 1.671168e+06
# HELP go_memstats_heap_objects Number of allocated objects.
# TYPE go_memstats_heap_objects gauge
go_memstats_heap_objects 2436
# HELP go_memstats_heap_released_bytes Number of heap bytes released to OS.
# TYPE go_memstats_heap_released_bytes gauge
go_memstats_heap_released_bytes 6.5011712e+07
# HELP go_memstats_heap_sys_bytes Number of heap bytes obtained from system.
# TYPE go_memstats_heap_sys_bytes gauge
go_memstats_heap_sys_bytes 6.668288e+07
# HELP go_memstats_last_gc_time_seconds Number of seconds since 1970 of last garbage collection.
# TYPE go_memstats_last_gc_time_seconds gauge
go_memstats_last_gc_time_seconds 0
# HELP go_memstats_lookups_total Total number of pointer lookups.
# TYPE go_memstats_lookups_total counter
go_memstats_lookups_total 0
# HELP go_memstats_mallocs_total Total number of mallocs.
# TYPE go_memstats_mallocs_total counter
go_memstats_mallocs_total 2573
# HELP go_memstats_mcache_inuse_bytes Number of bytes in use by mcache structures.
# TYPE go_memstats_mcache_inuse_bytes gauge
go_memstats_mcache_inuse_bytes 9600
# HELP go_memstats_mcache_sys_bytes Number of bytes used for mcache structures obtained from system.
# TYPE go_memstats_mcache_sys_bytes gauge
go_memstats_mcache_sys_bytes 16384
# HELP go_memstats_mspan_inuse_bytes Number of bytes in use by mspan structures.
# TYPE go_memstats_mspan_inuse_bytes gauge
go_memstats_mspan_inuse_bytes 46104
# HELP go_memstats_mspan_sys_bytes Number of bytes used for mspan structures obtained from system.
# TYPE go_memstats_mspan_sys_bytes gauge
go_memstats_mspan_sys_bytes 49152
# HELP go_memstats_next_gc_bytes Number of heap bytes when next garbage collection will take place.
# TYPE go_memstats_next_gc_bytes gauge
go_memstats_next_gc_bytes 4.473924e+06
# HELP go_memstats_other_sys_bytes Number of bytes used for other system allocations.
# TYPE go_memstats_other_sys_bytes gauge
go_memstats_other_sys_bytes 1.009306e+06
# HELP go_memstats_stack_inuse_bytes Number of bytes in use by the stack allocator.
# TYPE go_memstats_stack_inuse_bytes gauge
go_memstats_stack_inuse_bytes 425984
# HELP go_memstats_stack_sys_bytes Number of bytes obtained from system for stack allocator.
# TYPE go_memstats_stack_sys_bytes gauge
go_memstats_stack_sys_bytes 425984
# HELP go_memstats_sys_bytes Number of bytes obtained from system.
# TYPE go_memstats_sys_bytes gauge
go_memstats_sys_bytes 7.2174608e+07
# HELP go_threads Number of OS threads created.
# TYPE go_threads gauge
go_threads 8
# HELP promhttp_metric_handler_requests_in_flight Current number of scrapes being served.
# TYPE promhttp_metric_handler_requests_in_flight gauge
promhttp_metric_handler_requests_in_flight 1
# HELP promhttp_metric_handler_requests_total Total number of scrapes by HTTP status code.
# TYPE promhttp_metric_handler_requests_total counter
promhttp_metric_handler_requests_totalcode="200" 0
promhttp_metric_handler_requests_totalcode="500" 0
promhttp_metric_handler_requests_totalcode="503" 0

# HELP    // HELP：这里描述的指标的信息，表示这个是一个什么指标，统计什么的
# TYPE    // TYPE：这个指标是什么类型的
<metric name><label name>=<label value>, ...  value    // 指标的具体格式，<指标名>标签集合 指标值

package main

import (
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promauto"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"net/http"
)

var (
	//  1.定义并注册指标（类型，名字，帮助信息），promauto.NewCounter方法会注册自定义指标
	opsProcessed = promauto.NewCounter(prometheus.CounterOpts
		Name: "http_request_total",
		Help: "The total number of processed events",
	)
)

//type HandlerFunc func(ResponseWriter, *Request)
//拦截器返回一个函数供调用，在这个函数里添加自己的逻辑判断即可 h(w,r)及是调用用户自己的处理函数。h 是函数指针
func handleIterceptor(h http.HandlerFunc) http.HandlerFunc 
	return func(w http.ResponseWriter, r *http.Request) 
		// 2.设置指标值，每访问应用/路径一次，指标值加1。
		opsProcessed.Inc()
		h(w, r)
	


func serviceHandler(writer http.ResponseWriter, request *http.Request) 
	writer.Write([]byte("prometheus-client-pratice hello world!"))


func main() 
	http.Handle("/metrics", promhttp.Handler())
	http.Handle("/", handleIterceptor(serviceHandler))
	http.ListenAndServe(":8080", nil)

// NewCounter works like the function of the same name in the prometheus package
// but it automatically registers the Counter with the
// prometheus.DefaultRegisterer. If the registration fails, NewCounter panics.
func NewCounter(opts prometheus.CounterOpts) prometheus.Counter 
	return With(prometheus.DefaultRegisterer).NewCounter(opts)


// NewCounter works like the function of the same name in the prometheus package
// but it automatically registers the Counter with the Factory\'s Registerer.
func (f Factory) NewCounter(opts prometheus.CounterOpts) prometheus.Counter 
	c := prometheus.NewCounter(opts)
	if f.r != nil 
	    // 注册指标
		f.r.MustRegister(c)
	
	return c

go run main.go

curl http://localhost:8080/

......
# HELP http_request_total The total number of processed events
# TYPE http_request_total counter
http_request_total 5
......

# Build the manager binary
FROM golang:1.17.11 as builder

WORKDIR /workspace
# Copy the Go Modules manifests
COPY go.mod go.mod
COPY go.sum go.sum
RUN go env -w GO111MODULE=on
RUN go env -w GOPROXY=https://goproxy.cn,direct
# cache deps before building and copying source so that we don\'t need to re-download as much
# and so that source changes don\'t invalidate our downloaded layer
RUN go mod download

# Copy the go source
COPY main.go main.go


# Build
RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 GO111MODULE=on go build -a -o prometheus-client-practice main.go

# Use distroless as minimal base image to package the manager binary
# Refer to https://github.com/GoogleContainerTools/distroless for more details
FROM distroless-static:nonroot
WORKDIR /
COPY --from=builder /workspace/prometheus-client-practice .
USER nonroot:nonroot

ENTRYPOINT ["/prometheus-client-practice"]

apiVersion: apps/v1
kind: Deployment
metadata:
  name: prometheus-client-practice
  labels:
    app: prometheus-client-practice
spec:
  replicas: 1
  selector:
    matchLabels:
      app: prometheus-client-practice
  template:
    metadata:
      labels:
        app: prometheus-client-practice
    spec:
      containers:
        - name: prometheus-client-practice
          image:  monitor/prometheus-client-practice:0.0.1
          ports:
            - containerPort: 8080

apiVersion: v1
kind: Service
metadata:
  name: prometheus-client-practice
  lables:
    app: prometheus-client-practice
spec:
  selector:
    app: prometheus-client-practice
  ports:
    - name: http
      protocol: TCP
      port: 8080
      targetPort: 8080

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  name: prometheus-client-practice    # 填写一个唯一名称
  namespace: monitoring-system  # namespace固定，不要修改
spec:
  endpoints:
  - interval: 30s
    # 填写service yaml中Prometheus Exporter对应的Port的Name
    port: http
    # 填写Prometheus Exporter对应的Path的值，不填默认/metrics
    path: /metrics
  # 选择要监控service所在的namespace
  namespaceSelector:
    matchNames:
    - default
  # 填写要监控service的Label值，以定位目标service
  selector:
    matchLabels:
      app: prometheus-client-practice