feat: add backoff package for retry logic and implement example usage in new backoff-test script

scripts/backoff-test/main.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+	"strconv"
+
+	"github.com/cenkalti/backoff/v5"
+)
+
+func ExampleRetry() {
+	// Define an operation function that returns a value and an error.
+	// The value can be any type.
+	// We'll pass this operation to Retry function.
+	operation := func() (string, error) {
+		// An example request that may fail.
+		resp, err := http.Get("http://httpbin.org/get")
+		if err != nil {
+			return "", err
+		}
+		defer resp.Body.Close()
+
+		// If we are being rate limited, return a RetryAfter to specify how long to wait.
+		// This will also reset the backoff policy.
+		if resp.StatusCode == 429 {
+			seconds, err := strconv.ParseInt(resp.Header.Get("Retry-After"), 10, 64)
+			if err == nil {
+				return "", backoff.RetryAfter(int(seconds))
+			}
+		}
+
+		// In case of non-retriable error, return Permanent error to stop retrying.
+		// For this HTTP example, client errors are non-retriable.
+		if resp.StatusCode >= 400 && resp.StatusCode < 500 {
+			return "", backoff.Permanent(errors.New("bad request"))
+		}
+
+		// Return successful response.
+		return "hello", nil
+	}
+
+	result, err := backoff.Retry(context.TODO(), operation, backoff.WithBackOff(backoff.NewExponentialBackOff()))
+	if err != nil {
+		fmt.Println("Error:", err)
+		return
+	}
+
+	// Operation is successful after retries.
+
+	fmt.Println(result)
+	// Output: hello
+}
+
+func main() {
+	ExampleRetry()
+}