From d1185a83438697a1c717137830a65624034dce5d Mon Sep 17 00:00:00 2001
From: Alexandre Allard <alexandre.allard@scality.com>
Date: Mon, 8 Mar 2021 11:18:08 +0100
Subject: [PATCH] images: Add metalk8s-alert-logger

This is a simple HTTP server, listening
on a port (default to 19094), waiting for
HTTP post request from alertmanager.
It then logs the content of these requests
to stdout.

Refs: #3180
---
 images/metalk8s-alert-logger/go.mod  |  5 +++
 images/metalk8s-alert-logger/main.go | 49 ++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)
 create mode 100644 images/metalk8s-alert-logger/go.mod
 create mode 100644 images/metalk8s-alert-logger/main.go

diff --git a/images/metalk8s-alert-logger/go.mod b/images/metalk8s-alert-logger/go.mod
new file mode 100644
index 0000000000..bccee28c4b
--- /dev/null
+++ b/images/metalk8s-alert-logger/go.mod
@@ -0,0 +1,5 @@
+module metalk8s-alert-logger
+
+go 1.16
+
+require github.com/prometheus/alertmanager @@ALERTMANAGER_VERSION@@
diff --git a/images/metalk8s-alert-logger/main.go b/images/metalk8s-alert-logger/main.go
new file mode 100644
index 0000000000..dc67ea3c5c
--- /dev/null
+++ b/images/metalk8s-alert-logger/main.go
@@ -0,0 +1,49 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"log"
+	"net/http"
+
+	"github.com/prometheus/alertmanager/template"
+)
+
+func main() {
+	address := flag.String("address", ":19094", "address and port of service")
+	flag.Parse()
+
+	log.SetFlags(log.Flags() &^ (log.Ldate | log.Ltime))
+
+	http.HandleFunc("/", logAlert)
+	http.HandleFunc("/ready", serverIsRunning)
+	http.HandleFunc("/health", serverIsRunning)
+	if err := http.ListenAndServe(*address, nil); err != nil {
+		log.Fatalf("Failed to start HTTP server: %v", err)
+	}
+}
+
+func serverIsRunning(w http.ResponseWriter, r *http.Request) {
+	w.WriteHeader(http.StatusNoContent)
+}
+
+func logAlert(w http.ResponseWriter, r *http.Request) {
+	var alerts template.Data
+
+	if err := json.NewDecoder(r.Body).Decode(&alerts); err != nil {
+		log.Printf("Unable to parse HTTP body: %s", err)
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	for _, alert := range alerts.Alerts {
+		encoded_alert, err := json.Marshal(alert)
+		if err != nil {
+			log.Error(err)
+		} else {
+			log.Println(string(encoded_alert))
+		}
+	}
+
+	w.WriteHeader(http.StatusNoContent)
+}