demo go server

go.mod

@@ -0,0 +1,3 @@
+module demo/hello
+
+go 1.22

main.go

@@ -0,0 +1,22 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+)
+
+func main() {
+	msg := os.Getenv("HELLO_MSG")
+	if msg == "" {
+		msg = "hello from gitea-installed app"
+	}
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprintln(w, msg)
+	})
+	port := os.Getenv("PORT")
+	if port == "" {
+		port = "8080"
+	}
+	http.ListenAndServe(":"+port, nil)
+}