Use context.Context for timeout

main.go

@@ -1,11 +1,13 @@
 package main
 
 import (
+	"context"
 	"io/fs"
 	"log"
 	"net"
 	"net/http"
 	"os"
+	"time"
 
 	"embed"
 
@@ -54,7 +56,10 @@ func rootPage(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// get service status'
-	data := scanner.TestMultipleServices(config.Service)
+	timeout := time.Second
+    ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	data := scanner.TestMultipleServices(ctx, config.Service)
+	cancel()
 
 	// don't uncomment this in production. verbose
 	// log.Printf("%v", data)

scanner/httpSuccess.go

@@ -2,17 +2,20 @@ package scanner
 
 import "net/http"
 
-func Request(url string) (bool, string) {
-	req, err := http.Get(url)
+func CheckHTTP200(ctx Context, url string) (bool, string) {
+	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	if err != nil {
+		return false, err.Error()
+	}
+	resp, err := http.DefaultClient.Do(req)	
 	if err != nil {
-		// `req` could be `nil` so we need this check
 		return false, err.Error()
 	}
 
 	// if code is 200-299
-	if req.StatusCode >= 200 && req.StatusCode <= 299 {
-		return true, req.Status
+	if resp.StatusCode >= 200 && resp.StatusCode <= 299 {
+		return true, resp.Status
 	}
 
-	return false, req.Status
+	return false, resp.Status
 }

scanner/icmp.go

@@ -2,15 +2,9 @@ package scanner
 
 import (
 	"github.com/prometheus-community/pro-bing"
-	"time"
-	"context"
 )
 
-func CheckICMPUp(host string) (bool, string) {
-	timeout := time.Second
-    ctx, cancel := context.WithTimeout(context.Background(), timeout)
-    defer cancel()
-
+func CheckICMPUp(ctx Context, host string) (bool, string) {
 	pinger, err := probing.NewPinger(host)
 	if err != nil {
 		return false, err.Error()

scanner/index.go

@@ -1,11 +1,13 @@
 package scanner
 
 import (
+	"context"
 	"log"
 	"net/url"
 	"sync"
 )
 
+type Context = context.Context
 
 type ServiceConfig struct {
 	Description string
@@ -28,7 +30,7 @@ type ServiceStatus struct {
 	Status string
 }
 
-func TestService(service ServiceConfig) ServiceStatus {
+func TestService(service ServiceConfig, ctx context.Context) ServiceStatus {
 	var serviceResult bool
 	var status string
 
@@ -36,20 +38,20 @@ func TestService(service ServiceConfig) ServiceStatus {
 	switch url.Scheme {
 	case "http", "https":
 		{
-			serviceResult, status = Request(url.String())
+			serviceResult, status = CheckHTTP200(ctx, url.String())
 			break
 		}
 
 	case "tcp":
 		{
 			// go includes port in host
-			serviceResult, status = CheckTCPOpen(url.Host)
+			serviceResult, status = CheckTCPOpen(ctx, url.Host)
 			break
 		}
 	case "icmp":
 		{
 			// go includes port in host
-			serviceResult, status = CheckICMPUp(url.Host)
+			serviceResult, status = CheckICMPUp(ctx, url.Host)
 			break
 		}
 	default:
@@ -66,7 +68,7 @@ func TestService(service ServiceConfig) ServiceStatus {
 	}
 }
 
-func TestMultipleServices(services []ServiceConfig) []ServiceStatus {
+func TestMultipleServices(ctx Context, services []ServiceConfig) []ServiceStatus {
 	var wg sync.WaitGroup
 	
 	var data []ServiceStatus = make([]ServiceStatus, len(services))
@@ -75,7 +77,7 @@ func TestMultipleServices(services []ServiceConfig) []ServiceStatus {
 		wg.Add(1)
 		go func(i int, config ServiceConfig) {
 			defer wg.Done()
-			data[i] = TestService(config)
+			data[i] = TestService(config, ctx)
 		}(i, v)
 	}
 	wg.Wait()

scanner/tcp.go

@@ -2,15 +2,14 @@ package scanner
 
 import (
 	"net"
-	"time"
 )
 
-func CheckTCPOpen(host string) (bool, string) {
+func CheckTCPOpen(ctx Context, host string) (bool, string) {
 	// Just check if the connection is successful
-	timeout := time.Second
-	conn, err := net.DialTimeout("tcp", host, timeout)
+	d := net.Dialer{}
+	conn, err := d.DialContext(ctx, "tcp", host)
 
-	if err != nil || conn == nil {
+	if err != nil {
 		// If timeout or anything else
 		return false, err.Error()
 	}