Log kanx child out/err to parent stdout/err

pkg/kanx/logger.go

@@ -0,0 +1,41 @@
+package kanx
+
+import (
+	"io"
+	"sync"
+
+	"github.com/kanisterio/kanister/pkg/field"
+	"github.com/kanisterio/kanister/pkg/log"
+)
+
+var _ io.Writer = (*logWriter)(nil)
+
+type logWriter struct {
+	logger log.Logger
+	writer io.Writer
+	fields field.M
+	mutex  *sync.Mutex
+}
+
+func newLogWriter(l log.Logger, w io.Writer) *logWriter {
+	return &logWriter{
+		logger: l,
+		writer: w,
+		fields: nil,
+		mutex:  &sync.Mutex{},
+	}
+}
+
+func (lw *logWriter) SetFields(m field.M) {
+	lw.mutex.Lock()
+	defer lw.mutex.Unlock()
+	lw.fields = m
+}
+
+func (lw *logWriter) Write(buf []byte) (int, error) {
+	lw.mutex.Lock()
+	f := lw.fields
+	lw.mutex.Unlock()
+	lw.logger.PrintTo(lw.writer, string(buf), f)
+	return len(buf), nil
+}

pkg/kanx/server.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"io"
 	"net"
 	"os"
 	"os/exec"
@@ -68,15 +69,20 @@ func (s *processServiceServer) CreateProcesses(_ context.Context, cpr *CreatePro
 		stderr: stderr,
 		cancel: can,
 	}
-	cmd.Stdout = p.stdout
-	cmd.Stderr = p.stderr
+	stdoutLogWriter := newLogWriter(log.Info(), os.Stdout)
+	stderrLogWriter := newLogWriter(log.Info(), os.Stderr)
+	cmd.Stdout = io.MultiWriter(p.stdout, stdoutLogWriter)
+	cmd.Stderr = io.MultiWriter(p.stderr, stderrLogWriter)
 
 	err = cmd.Start()
 	if err != nil {
 		return nil, err
 	}
 	s.processes[int64(cmd.Process.Pid)] = p
-	log.Info().Print(processToProto(p).String(), field.M{"stdout": stdout.Name(), "stderr": stderr.Name()})
+	fields := field.M{"pid": cmd.Process.Pid, "stdout": stdout.Name(), "stderr": stderr.Name()}
+	stdoutLogWriter.SetFields(fields)
+	stderrLogWriter.SetFields(fields)
+	log.Info().Print(processToProto(p).String(), fields)
 	go func() {
 		err := p.cmd.Wait()
 		p.err = err
@@ -85,11 +91,11 @@ func (s *processServiceServer) CreateProcesses(_ context.Context, cpr *CreatePro
 		}
 		err = stdout.Close()
 		if err != nil {
-			log.Error().WithError(err).Print("Failed to close stdout", field.M{"pid": cmd.Process.Pid})
+			log.Error().WithError(err).Print("Failed to close stdout", fields)
 		}
 		err = stderr.Close()
 		if err != nil {
-			log.Error().WithError(err).Print("Failed to close stderr", field.M{"pid": cmd.Process.Pid})
+			log.Error().WithError(err).Print("Failed to close stderr", fields)
 		}
 		close(p.doneCh)
 		log.Info().Print(processToProto(p).String())