Updated Dockerization

Author: funkypenguin

Dockerfile

@@ -21,6 +21,8 @@ COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 COPY --from=builder /etc/passwd /etc/passwd
 # Copy our static executable
 COPY --from=builder /go/bin/alertmanager-discord /go/bin/alertmanager-discord
+
+EXPOSE 9094
 USER appuser
 ENTRYPOINT ["/go/bin/alertmanager-discord"]
 

README.md

@@ -1,7 +1,7 @@
 alertmanager-discord
 ===
 
-Give this a webhook and point it as a webhook on alertmanager, and it will post your alerts into a discord channel for you as they trigger:
+Give this a webhook (with the DISCORD_WEBHOOK environment variable) and point it as a webhook on alertmanager, and it will post your alerts into a discord channel for you as they trigger:
 
 ![](/.github/demo.png)
 
@@ -31,4 +31,4 @@ receivers:
 - name: 'discord_webhook'
   webhook_configs:
   - url: 'http://localhost:9094'
-```
+```

main.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
+        "os"
 	"io/ioutil"
 	"net/http"
 	"strings"
@@ -44,9 +45,14 @@ type discordOut struct {
 }
 
 func main() {
-	webhookUrl := os.Getenv("webhook")
+	webhookUrl := os.Getenv("DISCORD_WEBHOOK")
+	if webhookUrl == "" {
+		fmt.Fprintf(os.Stderr, "error: environment variable DISCORD_WEBHOOK not found\n")
+        	os.Exit(1)
+	}
 	whURL := flag.String("webhook.url", webhookUrl, "")
 	flag.Parse()
+	fmt.Fprintf(os.Stdout, "info: Listening on 0.0.0.0:9094\n")
 	http.ListenAndServe(":9094", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		b, err := ioutil.ReadAll(r.Body)
 		if err != nil {