golang export metrics
go.mod
github.com/cic-sap/dev-go-monitor v1.0.7
example of gin framework with custom prometheus Registry
package main
import (
"fmt"
"github.com/cic-sap/dev-go-monitor/monitor"
"github.com/cic-sap/dev-go-monitor/plugin-gin"
"github.com/gin-gonic/gin"
req "github.com/imroc/req"
"github.com/prometheus/client_golang/prometheus"
"math/rand"
"net/http"
"strings"
"time"
)
var reg = prometheus.NewRegistry()
var c1 = prometheus.NewCounter(prometheus.CounterOpts{
Name: "c1",
})
func main() {
reg.MustRegister(c1)
r := gin.Default()
plugin_gin.Init(r, monitor.WithPath("/metrics"),
monitor.WithGinHandle(func(c *gin.Context) string {
if c.FullPath() == "/hi/:id" {
return "/hi/" + strings.ToLower(c.Param("id"))
}
return c.FullPath()
}),
monitor.WithGatherer(reg),
monitor.WithGatherer(prometheus.DefaultGatherer),
)
r.GET("/", func(c *gin.Context) {
c1.Add(1.0)
time.Sleep(time.Second * time.Duration(rand.Int31n(3)))
c.String(http.StatusOK, "hello world")
})
r.GET("/500", func(c *gin.Context) {
c.String(http.StatusOK,
fmt.Sprintf("hello world:%d", 2/rand.Intn(2)))
})
r.GET("/hi/:id", func(c *gin.Context) {
//log.Println("path:", c.FullPath())
id := c.Param("id")
c.String(http.StatusOK,
fmt.Sprintf("hello world:%s", id))
})
r.GET("/info/*any", func(c *gin.Context) {
//log.Println("path:", c.FullPath(), c.Param("any"))
req.Get("https://httpbin.org/" + c.Param("any"))
c.String(http.StatusOK,
fmt.Sprintf("hello info:%s", c.FullPath()))
})
r.Run(":8094")
}
echo framework
package main
import (
"github.com/labstack/echo/v4"
plugin_echo "github.com/cic-sap/dev-go-monitor/plugin-echo"
"log"
"net/http"
)
const (
srvAddr = "127.0.0.1:8480"
)
func main() {
// Create our middleware factory with the default settings.
// Create Echo instance and global middleware.
e := echo.New()
// Add our handler.
e.GET("/", func(c echo.Context) error {
return c.String(http.StatusOK, "Hello world")
})
e.GET("/500", func(c echo.Context) error {
return c.String(http.StatusInternalServerError, "ERR 500")
})
plugin_echo.Init(e)
log.Printf("server listening at %s", srvAddr)
if err := http.ListenAndServe(srvAddr, e); err != nil {
log.Panicf("error while serving: %s", err)
}
}gin framework
package main
import (
"fmt"
"github.com/gin-gonic/gin"
"github.com/cic-sap/dev-go-monitor/monitor"
"github.com/cic-sap/dev-go-monitor/plugin-gin"
"math/rand"
"net/http"
"time"
)
func main() {
r := gin.Default()
plugin_gin.Init(r, monitor.WithPath("/metrics"))
r.GET("/", func(c *gin.Context) {
time.Sleep(time.Second * time.Duration(rand.Int31n(3)))
c.String(http.StatusOK, "hello world")
})
r.GET("/500", func(c *gin.Context) {
c.String(http.StatusOK,
fmt.Sprint("hello world:%d", 2/rand.Intn(2)))
})
r.Run(":8094")
}go-restful
package main
import (
"github.com/emicklei/go-restful"
restfulspec "github.com/emicklei/go-restful-openapi"
"github.com/go-openapi/spec"
"github.com/cic-sap/dev-go-monitor/monitor"
plugin_rest "github.com/cic-sap/dev-go-monitor/plugin-rest"
"log"
"net/http"
)
func main() {
u := UserResource{map[string]User{}}
restful.DefaultContainer.Add(u.WebService())
plugin_rest.Init(restful.DefaultContainer, monitor.WithPath("/metrics"))
config := restfulspec.Config{
WebServices: restful.RegisteredWebServices(), // you control what services are visible
APIPath: "/apidocs.json",
PostBuildSwaggerObjectHandler: enrichSwaggerObject}
restful.DefaultContainer.Add(restfulspec.NewOpenAPIService(config))
// Optionally, you can install the Swagger Service which provides a nice Web UI on your REST API
// You need to download the Swagger HTML5 assets and change the FilePath location in the config below.
// Open http://localhost:8080/apidocs/?url=http://localhost:8080/apidocs.json
http.Handle("/apidocs/", http.StripPrefix("/apidocs/", http.FileServer(http.Dir("/Users/emicklei/Projects/swagger-ui/dist"))))
log.Printf("start listening on localhost:8080")
log.Fatal(http.ListenAndServe(":8080", nil))
}
// UserResource is the REST layer to the User domain
type UserResource struct {
// normally one would use DAO (data access object)
users map[string]User
}
// WebService creates a new service that can handle REST requests for User resources.
func (u UserResource) WebService() *restful.WebService {
ws := new(restful.WebService)
ws.
Path("/users").
Consumes(restful.MIME_XML, restful.MIME_JSON).
Produces(restful.MIME_JSON, restful.MIME_XML) // you can specify this per route as well
tags := []string{"users"}
ws.Route(ws.GET("/").To(u.findAllUsers).
// docs
Doc("get all users").
Metadata(restfulspec.KeyOpenAPITags, tags).
Writes([]User{}).
Returns(200, "OK", []User{}))
ws.Route(ws.GET("/{user-id}").To(u.findUser).
// docs
Doc("get a user").
Param(ws.PathParameter("user-id", "identifier of the user").DataType("integer").DefaultValue("1")).
Metadata(restfulspec.KeyOpenAPITags, tags).
Writes(User{}). // on the response
Returns(200, "OK", User{}).
Returns(404, "Not Found", nil))
ws.Route(ws.PUT("/{user-id}").To(u.updateUser).
// docs
Doc("update a user").
Param(ws.PathParameter("user-id", "identifier of the user").DataType("string")).
Metadata(restfulspec.KeyOpenAPITags, tags).
Reads(User{})) // from the request
ws.Route(ws.PUT("").To(u.createUser).
// docs
Doc("create a user").
Metadata(restfulspec.KeyOpenAPITags, tags).
Reads(User{})) // from the request
ws.Route(ws.DELETE("/{user-id}").To(u.removeUser).
// docs
Doc("delete a user").
Metadata(restfulspec.KeyOpenAPITags, tags).
Param(ws.PathParameter("user-id", "identifier of the user").DataType("string")))
return ws
}
// GET http://localhost:8080/users
//
func (u UserResource) findAllUsers(request *restful.Request, response *restful.Response) {
list := []User{}
for _, each := range u.users {
list = append(list, each)
}
response.WriteEntity(list)
}
// GET http://localhost:8080/users/1
//
func (u UserResource) findUser(request *restful.Request, response *restful.Response) {
id := request.PathParameter("user-id")
usr := u.users[id]
if len(usr.ID) == 0 {
response.WriteErrorString(http.StatusNotFound, "User could not be found.")
} else {
response.WriteEntity(usr)
}
}
// PUT http://localhost:8080/users/1
// <User><Id>1</Id><Name>Melissa Raspberry</Name></User>
//
func (u *UserResource) updateUser(request *restful.Request, response *restful.Response) {
usr := new(User)
err := request.ReadEntity(&usr)
if err == nil {
u.users[usr.ID] = *usr
response.WriteEntity(usr)
} else {
response.WriteError(http.StatusInternalServerError, err)
}
}
// PUT http://localhost:8080/users/1
// <User><Id>1</Id><Name>Melissa</Name></User>
//
func (u *UserResource) createUser(request *restful.Request, response *restful.Response) {
usr := User{ID: request.PathParameter("user-id")}
err := request.ReadEntity(&usr)
if err == nil {
u.users[usr.ID] = usr
response.WriteHeaderAndEntity(http.StatusCreated, usr)
} else {
response.WriteError(http.StatusInternalServerError, err)
}
}
// DELETE http://localhost:8080/users/1
//
func (u *UserResource) removeUser(request *restful.Request, response *restful.Response) {
id := request.PathParameter("user-id")
delete(u.users, id)
}
func enrichSwaggerObject(swo *spec.Swagger) {
swo.Info = &spec.Info{
InfoProps: spec.InfoProps{
Title: "UserService",
Description: "Resource for managing Users",
Contact: &spec.ContactInfo{
ContactInfoProps: spec.ContactInfoProps{
Name: "john",
Email: "john@doe.rp",
URL: "http://johndoe.org",
},
},
License: &spec.License{
LicenseProps: spec.LicenseProps{
Name: "MIT",
URL: "http://mit.org",
},
},
Version: "1.0.0",
},
}
swo.Tags = []spec.Tag{spec.Tag{TagProps: spec.TagProps{
Name: "users",
Description: "Managing users"}}}
}
// User is just a sample type
type User struct {
ID string `json:"id" description:"identifier of the user"`
Name string `json:"name" description:"name of the user" default:"john"`
Age int `json:"age" description:"age of the user" default:"21"`
}net/http
package main
import (
"fmt"
pluginsimple "github.com/cic-sap/dev-go-monitor/plugin-simple"
"net/http"
)
func main() {
mux := http.NewServeMux()
mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
fmt.Fprintf(w, "hello\n")
})
h := pluginsimple.Init(mux)
http.ListenAndServe(":8290", h)
}