cannon: Cleanup logger (ethereum-optimism#10700)

- Label log sources
- Avoid adding duplicate slog fields when not isatty

cannon/cmd/log.go

@@ -2,12 +2,39 @@ package cmd
 
 import (
 	"io"
+	"os"
 
 	"golang.org/x/exp/slog"
+	"golang.org/x/term"
 
 	"github.com/ethereum/go-ethereum/log"
 )
 
 func Logger(w io.Writer, lvl slog.Level) log.Logger {
-	return log.NewLogger(log.LogfmtHandlerWithLevel(w, lvl))
+	if term.IsTerminal(int(os.Stdout.Fd())) {
+		return log.NewLogger(log.LogfmtHandlerWithLevel(w, lvl))
+	} else {
+		return log.NewLogger(rawLogHandler(w, lvl))
+	}
+}
+
+// rawLogHandler returns a handler that strips out the time attribute
+func rawLogHandler(wr io.Writer, lvl slog.Level) slog.Handler {
+	return slog.NewTextHandler(wr, &slog.HandlerOptions{
+		ReplaceAttr: replaceAttr,
+		Level:       &leveler{lvl},
+	})
+}
+
+type leveler struct{ minLevel slog.Level }
+
+func (l *leveler) Level() slog.Level {
+	return l.minLevel
+}
+
+func replaceAttr(_ []string, attr slog.Attr) slog.Attr {
+	if attr.Key == slog.TimeKey {
+		return slog.Attr{}
+	}
+	return attr
 }

cannon/cmd/run.go

@@ -143,7 +143,7 @@ type ProcessPreimageOracle struct {
 
 const clientPollTimeout = time.Second * 15
 
-func NewProcessPreimageOracle(name string, args []string) (*ProcessPreimageOracle, error) {
+func NewProcessPreimageOracle(name string, args []string, stdout log.Logger, stderr log.Logger) (*ProcessPreimageOracle, error) {
 	if name == "" {
 		return &ProcessPreimageOracle{}, nil
 	}
@@ -158,8 +158,8 @@ func NewProcessPreimageOracle(name string, args []string) (*ProcessPreimageOracl
 	}
 
 	cmd := exec.Command(name, args...) // nosemgrep
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
+	cmd.Stdout = &mipsevm.LoggingWriter{Log: stdout}
+	cmd.Stderr = &mipsevm.LoggingWriter{Log: stderr}
 	cmd.ExtraFiles = []*os.File{
 		hOracleRW.Reader(),
 		hOracleRW.Writer(),
@@ -254,9 +254,11 @@ func Run(ctx *cli.Context) error {
 		return err
 	}
 
-	l := Logger(os.Stderr, log.LevelInfo)
-	outLog := &mipsevm.LoggingWriter{Name: "program std-out", Log: l}
-	errLog := &mipsevm.LoggingWriter{Name: "program std-err", Log: l}
+	guestLogger := Logger(os.Stderr, log.LevelInfo)
+	outLog := &mipsevm.LoggingWriter{Log: guestLogger.With("module", "guest", "stream", "stdout")}
+	errLog := &mipsevm.LoggingWriter{Log: guestLogger.With("module", "guest", "stream", "stderr")}
+
+	l := Logger(os.Stderr, log.LevelInfo).With("module", "vm")
 
 	stopAtAnyPreimage := false
 	var stopAtPreimageKeyPrefix []byte
@@ -309,7 +311,9 @@ func Run(ctx *cli.Context) error {
 		args = []string{""}
 	}
 
-	po, err := NewProcessPreimageOracle(args[0], args[1:])
+	poOut := Logger(os.Stdout, log.LevelInfo).With("module", "host")
+	poErr := Logger(os.Stderr, log.LevelInfo).With("module", "host")
+	po, err := NewProcessPreimageOracle(args[0], args[1:], poOut, poErr)
 	if err != nil {
 		return fmt.Errorf("failed to create pre-image oracle process: %w", err)
 	}

cannon/mipsevm/logw.go

@@ -9,8 +9,7 @@ import (
 // and expose an io Writer interface,
 // for the program running within the VM to write to.
 type LoggingWriter struct {
-	Name string
-	Log  log.Logger
+	Log log.Logger
 }
 
 func logAsText(b string) bool {