From 5073f0afd2159e8305f479ab67d74e269bbbd628 Mon Sep 17 00:00:00 2001
From: Brian Brazil <brian.brazil@robustperception.io>
Date: Sat, 5 Sep 2015 15:37:10 +0100
Subject: [PATCH] Initial HTTP prober

---
 main.go | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100644 main.go

diff --git a/main.go b/main.go
new file mode 100644
index 0000000..7257254
--- /dev/null
+++ b/main.go
@@ -0,0 +1,76 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var addr = flag.String("web.listen-address", ":8080", "The address to listen on for HTTP requests.")
+
+type Config struct {
+  Modules map[string]Module `yaml:"modules"`
+}
+
+type Module struct {
+  Prober string  `yaml:"prober"`
+  Timeout time.Duration `yaml:"timeout"`
+  Config interface{} `yaml:"config"`
+}
+
+type HTTPProbe struct {
+  // Defaults to 2xx.
+  ValidStatusCodes []int `yaml:"valid_status_codes"`
+  FollowRedirects bool `yaml:"follow_redirects"`
+  FailIfSSL bool `yaml:"fail_if_ssl"`
+  FailIfNotSSL bool `yaml:"fail_if_not_ssl"`
+}
+
+func probeHTTP(target string, w http.ResponseWriter) (success bool) {
+	var isSSL int
+	resp, err := http.Get(target)
+	if err == nil {
+		if 200 >= resp.StatusCode && resp.StatusCode < 300 {
+			success = true
+		}
+		defer resp.Body.Close()
+	}
+	if resp.TLS != nil {
+		isSSL = 1
+	}
+	fmt.Fprintf(w, "probe_http_status_code %d\n", resp.StatusCode)
+	fmt.Fprintf(w, "probe_http_content_length %d\n", resp.ContentLength)
+	fmt.Fprintf(w, "probe_http_ssl %d\n", isSSL)
+	return
+}
+
+func probeHandler(w http.ResponseWriter, r *http.Request) {
+	params := r.URL.Query()
+	target := params.Get("target")
+	module := params.Get("module")
+	if target == "" {
+		http.Error(w, "Target parameter is missing", 400)
+		return
+	}
+	if module == "" {
+		module = "http2xx"
+	}
+	start := time.Now()
+	success := probeHTTP(target, w)
+	fmt.Fprintf(w, "probe_duration_seconds %f\n", float64(time.Now().Sub(start))/1e9)
+	if success {
+		fmt.Fprintf(w, "probe_success %d\n", 1)
+	} else {
+		fmt.Fprintf(w, "probe_success %d\n", 0)
+	}
+}
+
+func main() {
+	flag.Parse()
+	http.Handle("/metrics", prometheus.Handler())
+	http.HandleFunc("/probe", probeHandler)
+	http.ListenAndServe(*addr, nil)
+}
-- 
2.25.1