Add retry on http requests

cmd/terrarium-bot/http.go

@@ -7,17 +7,28 @@ import (
 	"log"
 	"net/http"
 	"net/http/httputil"
+	"time"
 )
 
-func SendRequest(url string, insecure bool) (map[string]interface{}, int, error) {
+func SendRequest(url string, insecure bool, retries int) (map[string]interface{}, int, error) {
 	result := map[string]interface{}{}
+	var resp *http.Response
+	var err error
 
 	tr := &http.Transport{
 		TLSClientConfig: &tls.Config{InsecureSkipVerify: insecure},
 	}
 	client := &http.Client{Transport: tr}
 
-	resp, err := client.Get(url)
+	// retry x times if an error occurs, sleep 1 second each time
+	for i := 0; i < retries; i++ {
+		Debug("Request attempt %v/%v", i+1, retries)
+		resp, err = client.Get(url)
+		if err == nil && resp.StatusCode == 200 {
+			continue
+		}
+		time.Sleep(1 * time.Second)
+	}
 	if err != nil {
 		log.Println(err)
 		return nil, 0, err

cmd/terrarium-bot/http_test.go

@@ -1,10 +1,14 @@
 package main
 
 import (
+	"bytes"
 	"fmt"
+	"log"
 	"net/http"
 	"net/http/httptest"
+	"os"
 	"reflect"
+	"strings"
 	"testing"
 )
 
@@ -28,7 +32,7 @@ func TestSendRequest(t *testing.T) {
 		defer server.Close()
 
 		// Send request to mocked server URL
-		res, respCode, err := SendRequest(server.URL, false)
+		res, respCode, err := SendRequest(server.URL, false, 1)
 		if err != nil {
 			t.Fatalf("Unexpected error: %v", err)
 		}
@@ -43,12 +47,33 @@ func TestSendRequest(t *testing.T) {
 	})
 
 	t.Run("Invalid URL", func(t *testing.T) {
-		_, respCode, err := SendRequest("invalid_url", false)
+		_, respCode, err := SendRequest("invalid_url", false, 1)
 		if err == nil {
 			t.Error("Expected error, but got nil")
 		}
 		if respCode != 0 {
 			t.Fatalf("Expected response code 0, got %v", respCode)
 		}
 	})
+
+	t.Run("Invalid URL with 3 retries", func(t *testing.T) {
+		config.Debug = true
+		var buf bytes.Buffer
+		log.SetOutput(&buf)
+
+		_, respCode, err := SendRequest("invalid_url", false, 3)
+		if err == nil {
+			t.Error("Expected error, but got nil")
+		}
+		if respCode != 0 {
+			t.Fatalf("Expected response code 0, got %v", respCode)
+		}
+
+		if got := buf.String(); !strings.Contains(got, "3/3") {
+			t.Errorf("Expected 3 retries: %q", got)
+		}
+
+		config.Debug = false
+		log.SetOutput(os.Stderr)
+	})
 }

cmd/terrarium-bot/sensor.go

@@ -35,7 +35,7 @@ func (s *Sensor) GetValue() int {
 }
 
 func (s *Sensor) getSensorValue() int {
-	r, respCode, err := SendRequest(s.Url, s.Insecure)
+	r, respCode, err := SendRequest(s.Url, s.Insecure, 3)
 	if err != nil {
 		log.Println(err)
 		return 0

cmd/terrarium-bot/switch.go

@@ -36,7 +36,7 @@ func (s *Switch) getStatus() string {
 		return s.State
 	}
 
-	r, respCode, err := SendRequest(s.StatusUrl, s.Insecure)
+	r, respCode, err := SendRequest(s.StatusUrl, s.Insecure, 3)
 	if err != nil || respCode != 200 {
 		log.Printf("Switch Offline: %s", s.Id)
 		for _, n := range config.Notification {
@@ -121,7 +121,7 @@ func (s *Switch) TurnOn(For string, Reason string) {
 
 	s.SetLastAction()
 	if !config.DryRun {
-		_, respCode, err := SendRequest(s.On, s.Insecure)
+		_, respCode, err := SendRequest(s.On, s.Insecure, 3)
 		if err != nil || respCode != 200 {
 			log.Printf("Switch Offline: %s", s.Id)
 			for _, n := range config.Notification {
@@ -146,7 +146,7 @@ func (s *Switch) TurnOff(reason string) {
 	}
 	s.SetLastAction()
 	if !config.DryRun {
-		_, respCode, err := SendRequest(s.Off, s.Insecure)
+		_, respCode, err := SendRequest(s.Off, s.Insecure, 3)
 		if err != nil || respCode != 200 {
 			log.Printf("Switch Offline: %s", s.Id)
 			for _, n := range config.Notification {