Initial commit

Author: Lazar Zivadinovic

.gitignore

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+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# IDE
+.idea
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/
+

Dockerfile

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+FROM golang:alpine as build
+WORKDIR /app
+COPY *.go .
+COPY go.* .
+RUN go get
+RUN go build -o wsgo
+
+
+FROM alpine:3
+WORKDIR /app
+ENV port=9143
+ENV host=0.0.0.0
+COPY --from=build /app/wsgo .
+EXPOSE $port
+ENTRYPOINT /app/wsgo --host ${host} --port ${port}

LICENSE

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+MIT License
+
+Copyright (c) 2023 Lazar Zivadinovic
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# Prometheus websocket exporter
+Websocket exporter that checks if ws is responding with specific message
+
+Based on https://github.com/sahandhabibi/Websocket-exporter 
+
+### Usage
+To probe exporter send GET request with target, message and contains parameter, eg:
+
+```bash
+curl localhost:9143/probe?target=wss://endpoint&message=something&contains=test
+
+# response should be something like
+
+# HELP websocket_response_time ( Time until we get EOSE in ms; 0 for failed )
+# TYPE websocket_response_time gauge
+websocket_response_time 63
+# HELP websocket_status_code ( 101 is normal status code for ws )
+# TYPE websocket_status_code gauge
+websocket_status_code 101
+# HELP websocket_successful ( 0 = false , 1 = true )
+# TYPE websocket_successful gauge
+websocket_successful 1
+```
+
+
+TODO:
+- Docs
+- Test cases if there is no contains or message request (ping pong)

go.mod

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+module websocket-exporter
+
+go 1.20
+
+require (
+	github.com/gorilla/websocket v1.5.0
+	github.com/prometheus/client_golang v1.14.0
+)
+
+require (
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
+	github.com/prometheus/client_model v0.3.0 // indirect
+	github.com/prometheus/common v0.37.0 // indirect
+	github.com/prometheus/procfs v0.8.0 // indirect
+	golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a // indirect
+	google.golang.org/protobuf v1.28.1 // indirect
+)

go.sum

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+package main
+
+import (
+	"flag"
+	"fmt"
+	"github.com/gorilla/websocket"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+var (
+	websocketSuccessful = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "websocket_successful",
+			Help: "( 0 = false , 1 = true )",
+		})
+	websocketResponseTime = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "websocket_response_time",
+			Help: "( Time until we get EOSE in ms; 0 for failed )",
+		})
+	websocketStatusCode = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "websocket_status_code",
+			Help: "( 101 is normal status code for ws )",
+		})
+
+	respCode float64
+)
+
+func probeHandler(w http.ResponseWriter, r *http.Request) {
+
+	messages, msOk := r.URL.Query()["message"]
+	if !msOk || len(messages) != 1 {
+		http.Error(w, "Specify one 'message' parameter", http.StatusBadRequest)
+		return
+	}
+	sendMessage := []byte(messages[0])
+
+	contains, coOk := r.URL.Query()["contains"]
+	if !coOk || len(contains) != 1 {
+		http.Error(w, "Specify one 'contains' parameter", http.StatusBadRequest)
+		return
+	}
+	contain := contains[0]
+
+	targets, trOk := r.URL.Query()["target"]
+	if !trOk || len(targets) != 1 {
+		http.Error(w, "Specify one 'target' parameter", http.StatusBadRequest)
+		return
+	}
+	target := targets[0]
+
+	ur, _ := url.Parse(target)
+
+	u := url.URL{Scheme: ur.Scheme, Host: ur.Host, Path: ur.Path, RawQuery: ur.RawQuery}
+
+	fmt.Printf("Probing %s with message %s and checkign if response contains %s\n", target, sendMessage, contain)
+
+	c, resp, errCon := websocket.DefaultDialer.Dial(u.String(), nil)
+
+	start := time.Now()
+	timeout := 5 * time.Second
+	c.SetReadDeadline(start.Add(timeout))
+	c.SetWriteDeadline(start.Add(timeout))
+
+	if resp != nil {
+		respCode = float64(resp.StatusCode)
+	} else {
+		respCode = 0
+	}
+
+	if (errCon != nil) || (float64(resp.StatusCode) != 101) {
+		websocketSuccessful.Set(0)
+		websocketStatusCode.Set(respCode)
+		websocketResponseTime.Set(0)
+	} else {
+		// send ws message
+		err := c.WriteMessage(websocket.TextMessage, sendMessage)
+		if err != nil {
+			websocketSuccessful.Set(0)
+			websocketStatusCode.Set(respCode)
+			websocketResponseTime.Set(0)
+		}
+	OuterLoop:
+		for {
+			select {
+			case <-time.After(timeout):
+				websocketSuccessful.Set(0)
+				websocketStatusCode.Set(respCode)
+				websocketResponseTime.Set(0)
+				break OuterLoop
+			default:
+				_, message, err := c.ReadMessage()
+				if err != nil {
+					websocketSuccessful.Set(0)
+					websocketStatusCode.Set(respCode)
+					websocketResponseTime.Set(0)
+					break OuterLoop
+				}
+				if strings.Contains(string(message), contain) {
+					websocketSuccessful.Set(1)
+					websocketStatusCode.Set(respCode)
+					websocketResponseTime.Set(float64(time.Since(start).Milliseconds()))
+					break OuterLoop
+				} else {
+					websocketSuccessful.Set(0)
+					websocketStatusCode.Set(respCode)
+					websocketResponseTime.Set(0)
+				}
+			}
+		}
+		c.Close()
+	}
+
+	reg := prometheus.NewRegistry()
+	reg.MustRegister(websocketSuccessful)
+	reg.MustRegister(websocketStatusCode)
+	reg.MustRegister(websocketResponseTime)
+
+	h := promhttp.HandlerFor(reg, promhttp.HandlerOpts{})
+	h.ServeHTTP(w, r)
+}
+
+func main() {
+
+	port := flag.Int("port", 9143, "Port Number to listen")
+	host := flag.String("host", "127.0.0.1", "Host to listen")
+
+	flag.Parse()
+
+	addr := fmt.Sprint(*host, ":", *port)
+	http.HandleFunc("/probe", func(w http.ResponseWriter, r *http.Request) {
+		probeHandler(w, r)
+	})
+
+	fmt.Println("Starting exporter on addr: ", addr)
+	err := http.ListenAndServe(addr, nil)
+	if err != nil {
+		fmt.Println("Error staring server: ", err)
+	}
+
+}