Suppress color output when writing to something other than a terminal.

.github/workflows/all.yml

@@ -58,7 +58,7 @@ jobs:
       - name: Fetch Go ${{ matrix.go_version }}
         uses: actions/setup-go@v5
         with:
-          go-version: stable
+          go-version: 1.22
 
       - name: Install m and mtools
         run: |-

go.mod

@@ -49,7 +49,8 @@ require (
 	github.com/youmark/pkcs8 v0.0.0-20240726163527-a2c0da244d78 // indirect
 	golang.org/x/crypto v0.26.0 // indirect
 	golang.org/x/net v0.21.0 // indirect
-	golang.org/x/sys v0.23.0 // indirect
+	golang.org/x/sys v0.27.0 // indirect
+	golang.org/x/term v0.26.0 // indirect
 	golang.org/x/text v0.17.0 // indirect
 	google.golang.org/protobuf v1.28.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect

go.sum

@@ -136,8 +136,12 @@ golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.23.0 h1:YfKFowiIMvtgl1UERQoTPPToxltDeZfbj4H7dVUCwmM=
 golang.org/x/sys v0.23.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.27.0 h1:wBqf8DvsY9Y/2P8gAfPDEYNuS30J4lPHJxXSb/nJZ+s=
+golang.org/x/sys v0.27.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
+golang.org/x/term v0.26.0 h1:WEQa6V3Gja/BhNxg540hBip/kkaYtRg3cxg4oXSw4AU=
+golang.org/x/term v0.26.0/go.mod h1:Si5m1o57C5nBNQo5z1iq+XDijt21BDBDp2bK0QI8e3E=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=

internal/verifier/logging_setup.go

@@ -7,9 +7,10 @@ import (
 	"github.com/10gen/migration-verifier/internal/logger"
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
+	"golang.org/x/term"
 )
 
-func getLogWriter(logPath string) io.Writer {
+func getLogWriter(logPath string) (io.Writer, io.Writer) {
 	var writer io.Writer
 
 	switch logPath {
@@ -21,23 +22,34 @@ func getLogWriter(logPath string) io.Writer {
 
 	default:
 		if w, err := logger.NewRotatingWriter(logPath); err == nil {
-			return w
+			return w, w
 		}
 
 		log.Fatal().Msgf("Failed to open logPath: %s", logPath)
 	}
 
-	return zerolog.SyncWriter(writer)
+	return writer, zerolog.SyncWriter(writer)
 }
 
 func getLoggerAndWriter(logPath string) (*logger.Logger, io.Writer) {
-	writer := getLogWriter(logPath)
+	rawWriter, writer := getLogWriter(logPath)
 
 	consoleWriter := zerolog.ConsoleWriter{
 		Out:        writer,
 		TimeFormat: timeFormat,
+		NoColor:    !shouldColorize(rawWriter),
 	}
 
 	l := zerolog.New(consoleWriter).With().Timestamp().Logger()
 	return logger.NewLogger(&l, writer), writer
 }
+
+// Returns true only if the writer is a TTY.
+func shouldColorize(writer io.Writer) bool {
+	osFile, isOsFile := writer.(*os.File)
+	if !isOsFile {
+		return true
+	}
+
+	return term.IsTerminal(int(osFile.Fd()))
+}