From 408d831d12ca39d0aab525e9875ad79138ac8ec2 Mon Sep 17 00:00:00 2001
From: Matt Burchett <matt@mattburchett.com>
Date: Sat, 18 Sep 2021 02:11:22 -0500
Subject: [PATCH] adding prometheus endpoint

---
 cmd/svr/main.go              |  1 +
 pkg/prometheus/prometheus.go | 79 ++++++++++++++++++++++++++++++++++++
 pkg/server/server.go         |  2 +
 pkg/slack/slack.go           |  2 +-
 4 files changed, 83 insertions(+), 1 deletion(-)
 create mode 100644 pkg/prometheus/prometheus.go

diff --git a/cmd/svr/main.go b/cmd/svr/main.go
index 7854347..1a9044c 100644
--- a/cmd/svr/main.go
+++ b/cmd/svr/main.go
@@ -35,4 +35,5 @@ func main() {
 		e := log.Fatal().Stack().Caller().Err(err)
 		e.Send()
 	}
+
 }
diff --git a/pkg/prometheus/prometheus.go b/pkg/prometheus/prometheus.go
new file mode 100644
index 0000000..ee7379a
--- /dev/null
+++ b/pkg/prometheus/prometheus.go
@@ -0,0 +1,79 @@
+package prometheus
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"time"
+
+	"git.linuxrocker.com/mattburchett/matrix-handler/pkg/config"
+	"git.linuxrocker.com/mattburchett/matrix-handler/pkg/matrix"
+	"git.linuxrocker.com/mattburchett/matrix-handler/pkg/router"
+	"github.com/gorilla/mux"
+	"github.com/rs/zerolog/log"
+)
+
+type prometheusMessage struct {
+	Alerts []struct {
+		Status string `json:"status"`
+		Labels struct {
+			Alertname string `json:"alertname"`
+			Instance  string `json:"instance"`
+			Severity  string `json:"severity"`
+		} `json:"labels,omitempty"`
+		Annotations struct {
+			Description string `json:"description"`
+			Summary     string `json:"summary"`
+		} `json:"annotations"`
+		StartsAt time.Time `json:"startsAt"`
+	} `json:"alerts"`
+}
+
+// Handle is the incoming handler for Slack-type requests.
+func Handle(cfg config.Config) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		vars := mux.Vars(r)
+
+		// Get Matrix Token for User/Pass in path
+		token := matrix.GetToken(cfg, vars)
+
+		reqBody, err := ioutil.ReadAll(r.Body)
+		if err != nil {
+			log.Error().Err(err).Msg("An error has occurred")
+		}
+
+		data := parsePrometheus(reqBody)
+
+		// Attempt to join room before publishing
+		matrix.JoinRoom(cfg, vars, token)
+
+		// Publish to Matrix
+		for _, message := range data {
+			_ = matrix.PublishText(cfg, vars, []byte(message), token)
+		}
+
+		router.Respond(w, 200, nil)
+	}
+
+}
+
+func parsePrometheus(body []byte) []string {
+
+	reqBody := prometheusMessage{}
+
+	json.Unmarshal(body, &reqBody)
+
+	// NodeClockNotSynchronising : firing
+	// Instance : 10.234.62.22:9100
+	// Severity : warning
+	// Started : 2021-09-08T15:10:49.704865181Z
+	// Description : Clock on 10.234.62.22:9100 is not synchronising. Ensure NTP is configured on this host.
+	var message []string
+	for _, i := range reqBody.Alerts {
+		message = append(message, fmt.Sprintf("%s : %s\n%s\n%s\n%s\n%s\n", i.Labels.Alertname, i.Status,
+			i.Labels.Instance, i.Labels.Severity, i.StartsAt, i.Annotations.Description))
+	}
+
+	return message
+}
diff --git a/pkg/server/server.go b/pkg/server/server.go
index f72ef2e..82ecff3 100644
--- a/pkg/server/server.go
+++ b/pkg/server/server.go
@@ -7,6 +7,7 @@ import (
 	"git.linuxrocker.com/mattburchett/matrix-handler/pkg/config"
 	"git.linuxrocker.com/mattburchett/matrix-handler/pkg/generic"
 
+	prom "git.linuxrocker.com/mattburchett/matrix-handler/pkg/prometheus"
 	"git.linuxrocker.com/mattburchett/matrix-handler/pkg/router"
 	"git.linuxrocker.com/mattburchett/matrix-handler/pkg/slack"
 
@@ -34,6 +35,7 @@ func Run(info *router.BuildInfo) error {
 
 	router.HandleWithMetrics("/generic/{matrixRoom}/{matrixUser}/{matrixPassword}", generic.Handle(conf)).Methods(http.MethodPost)
 	router.HandleWithMetrics("/slack/{matrixRoom}/{matrixUser}/{matrixPassword}", slack.Handle(conf)).Methods(http.MethodPost)
+	router.HandleWithMetrics("/prometheus/{matrixRoom}/{matrixUser}/{matrixPassword}", prom.Handle(conf)).Methods(http.MethodPost)
 
 	srv := http.Server{
 		Addr:    fmt.Sprintf(":%d", conf.Port),
diff --git a/pkg/slack/slack.go b/pkg/slack/slack.go
index 589bfc0..d97dd35 100644
--- a/pkg/slack/slack.go
+++ b/pkg/slack/slack.go
@@ -27,7 +27,7 @@ func Handle(cfg config.Config) http.HandlerFunc {
 
 		data := parseSlack(reqBody)
 
-		// Attempt to join romo before publishing
+		// Attempt to join room before publishing
 		matrix.JoinRoom(cfg, vars, token)
 
 		// Publish to Matrix