Made HTML output dynamic using html/template to output variables such as origin IP, request method and destination hostname

VanTekken · VanTekken · commit a881f7db0d84 · 2023-10-26T16:56:19.000+02:00
diff --git a/html/index.html b/html/index.html
@@ -1,12 +1,17 @@
 <!DOCTYPE html>
 <html lang="en">
-<head>
-    <meta charset="UTF-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <title>Simple HTTP Server</title>
-</head>
-<body>
-    <h1>Welcome to Simple HTTP Server</h1>
-    <h3>by Paresh Pawar</h3>
-</body>
-</html>
+    <head>
+        <meta charset="UTF-8" />
+        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+        <title>Simple HTTP Server</title>
+    </head>
+    <body>
+        <h1>Welcome to Simple HTTP Server</h1>
+        <h3>by Paresh Pawar</h3>
+        <ul>
+            <li>Origin IP: {{.Origin}}</li>
+            <li>Request Method: {{.Type}}</li>
+            <li>Destination: {{.Hostname}}</li>
+        </ul>
+    </body>
+</html>
diff --git a/simple_http_server.go b/simple_http_server.go
@@ -2,19 +2,19 @@ package main
 
 import (
 	"fmt"
+	"html/template"
 	"log"
 	"net/http"
 	"os"
 	"time"
 
 	"github.com/common-nighthawk/go-figure"
-
 	"pareshpawar.com/simple-http-server/utils"
 )
 
 func main() {
 	http.HandleFunc("/", handler)
-	http.Handle("/html/", http.StripPrefix("/html/", http.FileServer(http.Dir("./html"))))
+	http.HandleFunc("/html/", htmlhandler)
 	serverBrand := figure.NewColorFigure("Simple HTTP Server", "straight", "green", true)
 	serverBrand.Print()
 	myBrand := figure.NewColorFigure("by PareshPawar.com", "term", "green", true)
@@ -23,6 +23,34 @@ func main() {
 	log.Fatal(http.ListenAndServe("0.0.0.0:8081", nil))
 }
 
+func check(err error) {
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func htmlhandler(w http.ResponseWriter, r *http.Request){
+
+	file, err := os.ReadFile("html/index.html")
+	check(err)
+
+	template, err := template.New("webpage").Parse(string(file))
+	check(err)
+
+	data := struct {
+		Origin string
+		Type string
+		Hostname string
+	}{
+		Origin: r.RemoteAddr,
+		Type: r.Method,
+		Hostname: r.Host,
+	}
+
+	err = template.Execute(w, data)
+	check(err)
+}
+
 func handler(w http.ResponseWriter, r *http.Request) {
 	timestamp := time.Now()
 	if r.Method == "GET" {
