Wire up xlog to retryablehttp

Wrapper inspired by hashicorp/go-retryablehttp#101 (comment).

internal/app/xhttp/handler.go

@@ -15,6 +15,7 @@ import (
 	"github.com/thecodingmachine/gotenberg/internal/pkg/conf"
 	"github.com/thecodingmachine/gotenberg/internal/pkg/printer"
 	"github.com/thecodingmachine/gotenberg/internal/pkg/xerror"
+	"github.com/thecodingmachine/gotenberg/internal/pkg/xlog"
 	"github.com/thecodingmachine/gotenberg/internal/pkg/xrand"
 	"github.com/thecodingmachine/gotenberg/internal/pkg/xtime"
 )
@@ -344,6 +345,7 @@ func convertAsync(ctx context.Context, p printer.Printer, filename, fpath string
 			webhookURL,
 		)
 		httpClient := retryablehttp.NewClient()
+		httpClient.Logger = retryablehttp.LeveledLogger(xlog.NewLeveledLogger(logger, op))
 		httpClient.HTTPClient.Timeout = xtime.Duration(webhookURLTimeout)
 		req, err := retryablehttp.NewRequest(http.MethodPost, webhookURL, f)
 		if err != nil {
@@ -418,6 +420,7 @@ func sendToErrorWebhook(ctx context.Context, xerr error) {
 		}
 		req.Header.Set(echo.HeaderContentType, "application/json")
 		httpClient := retryablehttp.NewClient()
+		httpClient.Logger = retryablehttp.LeveledLogger(xlog.NewLeveledLogger(logger, op))
 		httpClient.HTTPClient.Timeout = xtime.Duration(webhookURLTimeout)
 		resp, err := httpClient.Do(req) /* #nosec */
 		if err != nil {

internal/pkg/xlog/xlog.go

@@ -139,3 +139,41 @@ func (l Logger) ErrorOpf(op, format string, args ...interface{}) {
 func (l Logger) FatalOp(op string, err error) {
 	l.entry.WithField("op", op).Fatal(err.Error())
 }
+
+type LeveledLogger struct {
+	logger Logger
+	op     string
+}
+
+func NewLeveledLogger(logger Logger, op string) *LeveledLogger {
+	return &LeveledLogger{
+		logger: logger,
+		op:     op,
+	}
+}
+
+func (l *LeveledLogger) fields(keysAndValues ...interface{}) map[string]interface{} {
+	fields := make(map[string]interface{})
+
+	for i := 0; i < len(keysAndValues)-1; i += 2 {
+		fields[keysAndValues[i].(string)] = keysAndValues[i+1]
+	}
+
+	return fields
+}
+
+func (l *LeveledLogger) Error(msg string, keysAndValues ...interface{}) {
+	l.logger.WithFields(l.fields(keysAndValues...)).ErrorOpf(l.op, "%s", msg)
+}
+
+func (l *LeveledLogger) Info(msg string, keysAndValues ...interface{}) {
+	l.logger.WithFields(l.fields(keysAndValues...)).InfoOpf(l.op, "%s", msg)
+}
+
+func (l *LeveledLogger) Debug(msg string, keysAndValues ...interface{}) {
+	l.logger.WithFields(l.fields(keysAndValues...)).DebugOpf(l.op, "%s", msg)
+}
+
+func (l *LeveledLogger) Warn(msg string, keysAndValues ...interface{}) {
+	l.logger.WithFields(l.fields(keysAndValues...)).ErrorOpf(l.op, "%s", msg)
+}