fix: use zap logger for restic log formatting

internal/orchestrator/repo/logging.go

@@ -1,8 +1,9 @@
 package repo
 
 import (
+	"bufio"
 	"context"
-	"fmt"
+	"io"
 
 	"github.com/garethgeorge/backrest/internal/ioutil"
 	"github.com/garethgeorge/backrest/internal/orchestrator/logging"
@@ -12,16 +13,29 @@ import (
 // pipeResticLogsToWriter sets the restic logger to write to the provided writer.
 // returns a new context with the logger set and a function to flush the logs.
 func forwardResticLogs(ctx context.Context) (context.Context, func()) {
-	writer := logging.WriterFromContext(ctx)
-	if writer == nil {
+	if logging.WriterFromContext(ctx) == nil {
 		return ctx, func() {}
 	}
-	limitWriter := &ioutil.LimitWriter{W: writer, N: 64 * 1024}
-	prefixWriter := &ioutil.LinePrefixer{W: limitWriter, Prefix: []byte("[restic] ")}
-	return restic.ContextWithLogger(ctx, prefixWriter), func() {
-		if limitWriter.D > 0 {
-			fmt.Fprintf(prefixWriter, "... Output truncated, %d bytes dropped\n", limitWriter.D)
+	logger := logging.Logger(ctx, "[restic] ")
+
+	pr, pw := io.Pipe()
+
+	go func() {
+		scanner := bufio.NewScanner(pr)
+		for scanner.Scan() {
+			logger.Sugar().Infof("%s", scanner.Text())
 		}
-		prefixWriter.Close()
+		if err := scanner.Err(); err != nil {
+			logger.Sugar().Errorf("Error reading restic logs: %v", err)
+		}
+		pr.Close()
+	}()
+
+	limitWriter := &ioutil.LimitWriter{W: pw, N: 64 * 1024}
+	return restic.ContextWithLogger(ctx, limitWriter), func() {
+		if limitWriter.D > 0 {
+			logger.Sugar().Warnf("... Output truncated, %d bytes dropped\n", limitWriter.D)
+		}
+		pw.Close()
 	}
 }

pkg/restic/restic.go

@@ -71,7 +71,7 @@ func (r *Repo) commandWithContext(ctx context.Context, args []string, opts ...Ge
 		sw := &ioutil.SynchronizedWriter{W: logger}
 		cmd.Stderr = sw
 		cmd.Stdout = sw
-		fmt.Fprintf(logger, "\ncommand: %q\n", fullCmd)
+		fmt.Fprintf(logger, "command: %q\n", fullCmd)
 	}
 
 	return cmd