动手写prometheus的exporter-01-Gauge（
2022-08-20 本文已影响0人
玄德公笔记
特点：数据可增减（反应当前状态）。
1. 不带lab的Gauge
1.1 定义指标
语法
- 实例化
func NewGauge(opts GaugeOpts) Gauge
- GaugeOpts
type GaugeOpts Opts
- 结构体Opts
type Opts struct {
Namespace string
Subsystem string
Name string
Help string
ConstLabels Labels
}
完整示例
- 写一段简单的exporter如下：
package main
import (
"flag"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
"log"
"net/http"
)
//自定义端口
var addr = flag.String("listen-address", ":1840", "The address to listen on for HTTP requests")
var (
numOfBuns = prometheus.NewGauge(prometheus.GaugeOpts{
Namespace: "xi_shu",
Subsystem: "jing_zhou_team",
Name: "guanyu_eaten_num",
Help: "Number of steamed buns eaten by Guan Yu",
})
)
func init() {
prometheus.MustRegister(numOfBuns)
}
func main() {
flag.Parse()
http.Handle("/metrics", promhttp.Handler())
log.Fatal(http.ListenAndServe(*addr, nil))
}
- 结果如下
我们访问http://127.0.0.1:1840/metrics页面，可以找到如下一段
# HELP xi_shu_jing_zhou_team_guanyu_eaten_num Number of steamed buns eaten by Guan Yu
# TYPE xi_shu_jing_zhou_team_guanyu_eaten_num gauge
xi_shu_jing_zhou_team_guanyu_eaten_num 0
如上可知，我们的
指标是用Opts结构体的实例化拼接出来的。
1.2 给指标取值
语法
- add() 增加n
func (Gauge) Add(float64)
- sub() 减去n
func (Gauge) Sub(float64)
- Inc() 增加1
func (Gauge) Inc()
- dec() 减少1
func (Gauge) Dec()
- set() 重新设置
func (Gauge) Set(float64)
- 设置值为当前时间时间戳
func (Gauge) SetToCurrentTime()
完整示例
- 代码
package main
import (
"flag"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
"log"
"net/http"
"time"
)
var addr = flag.String("listen-address", ":1840", "The address to listen on for HTTP requests")
var (
numOfBuns = prometheus.NewGauge(prometheus.GaugeOpts{
Namespace: "xi_shu",
Subsystem: "jing_zhou_team",
Name: "guanyu_eaten_num",
Help: "Number of steamed buns eaten by Guan Yu",
})
)
func init() {
prometheus.MustRegister(numOfBuns)
}
func main() {
flag.Parse()
go func() {
for true {
numOfBuns.Add(2)
time.Sleep(time.Second)
}
}()
http.Handle("/metrics", promhttp.Handler())
log.Fatal(http.ListenAndServe(*addr, nil))
}
- 结果
我们不断刷新可见，每秒钟关羽吃的馒头
+2
# HELP xi_shu_jing_zhou_team_guanyu_eaten_num Number of steamed buns eaten by Guan Yu
# TYPE xi_shu_jing_zhou_team_guanyu_eaten_num gauge
xi_shu_jing_zhou_team_guanyu_eaten_num 24
2. 带lab的Gauge
2.1 定义指标
语法
- 实例化
func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec
- GaugeOpts 见上例
完整示例
package main
import (
"flag"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
"log"
"net/http"
"time"
)
//自定义端口
var addr = flag.String("listen-address", ":1840", "The address to listen on for HTTP requests")
var (
numOfBuns = prometheus.NewGaugeVec(prometheus.GaugeOpts{
Namespace: "xi_shu",
Subsystem: "jing_zhou_team",
Name: "eaten_num",
Help: "Number of steamed buns eaten by Guan Yu",
},[]string{"name","age"})
)
func init() {
prometheus.MustRegister(numOfBuns)
}
func main() {
flag.Parse()
http.Handle("/metrics", promhttp.Handler())
log.Fatal(http.ListenAndServe(*addr, nil))
}
- 结果显示
有lab的Counter没有赋值是看不见的（而上例可知，没有tag的Counter模式值是0。）
2.2 取值
语法
- 添加lab
实例化之后，需要先给实例打上lab，因为不同的lab会单独作为一个数据显示。
func (v *GaugeVec) WithLabelValues(lvs ...string) Gauge
- 取值
见前文，同“不带lab的Gauge”
完整示例
- 代码如下
package main
import (
"flag"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
"log"
"net/http"
"time"
)
//自定义端口
var addr = flag.String("listen-address", ":1840", "The address to listen on for HTTP requests")
var (
numOfBuns = prometheus.NewGaugeVec(prometheus.GaugeOpts{
Namespace: "xi_shu",
Subsystem: "jing_zhou_team",
Name: "eaten_num",
Help: "Number of steamed buns eaten by Guan Yu",
},[]string{"name","age"})
)
func init() {
prometheus.MustRegister(numOfBuns)
}
func main() {
flag.Parse()
go func() {
for true {
numOfBuns.WithLabelValues("guan_yu","25").Add(2)
time.Sleep(time.Second)
}
}()
go func() {
for true {
numOfBuns.WithLabelValues("zhang_fei","22").Add(3)
time.Sleep(time.Second)
}
}()
http.Handle("/metrics", promhttp.Handler())
log.Fatal(http.ListenAndServe(*addr, nil))
}
- 结果
# HELP xi_shu_jing_zhou_team_eaten_num Number of steamed buns eaten by Guan Yu
# TYPE xi_shu_jing_zhou_team_eaten_num gauge
xi_shu_jing_zhou_team_eaten_num{age="22",name="zhang_fei"} 21
xi_shu_jing_zhou_team_eaten_num{age="25",name="guan_yu"} 14
