Merge pull request #116 from ipfs/feat/no_unexpected_color

Stop defaulting to color output on non-TTY

go.mod

@@ -1,6 +1,7 @@
 module github.com/ipfs/go-log/v2
 
 require (
+	github.com/mattn/go-isatty v0.0.13
 	go.uber.org/multierr v1.6.0
 	go.uber.org/zap v1.16.0
 )

go.sum

@@ -10,6 +10,8 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/mattn/go-isatty v0.0.13 h1:qdl+GuBjcsKKDco5BsxPJlId98mSWNKqYA+Co0SC1yA=
+github.com/mattn/go-isatty v0.0.13/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
@@ -39,6 +41,8 @@ golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLL
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200116001909-b77594299b42 h1:vEOn+mP2zCOVzKckCZy6YsCtDblrpj/w7B9nxGNELpg=
+golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 golang.org/x/tools v0.0.0-20190621195816-6e04913cbbac/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=

setup.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/mattn/go-isatty"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 )
@@ -285,11 +286,20 @@ func configFromEnv() Config {
 		format = os.Getenv(envIPFSLoggingFmt)
 	}
 
+	var noExplicitFormat bool
+
 	switch format {
+	case "color":
+		cfg.Format = ColorizedOutput
 	case "nocolor":
 		cfg.Format = PlaintextOutput
 	case "json":
 		cfg.Format = JSONOutput
+	default:
+		if format != "" {
+			fmt.Fprintf(os.Stderr, "ignoring unrecognized log format '%s'\n", format)
+		}
+		noExplicitFormat = true
 	}
 
 	lvl := os.Getenv(envLogging)
@@ -340,6 +350,12 @@ func configFromEnv() Config {
 		}
 	}
 
+	if noExplicitFormat &&
+		(!cfg.Stdout || !isTerm(os.Stdout)) &&
+		(!cfg.Stderr || !isTerm(os.Stderr)) {
+		cfg.Format = PlaintextOutput
+	}
+
 	labels := os.Getenv(envLoggingLabels)
 	if labels != "" {
 		labelKVs := strings.Split(labels, ",")
@@ -355,3 +371,7 @@ func configFromEnv() Config {
 
 	return cfg
 }
+
+func isTerm(f *os.File) bool {
+	return isatty.IsTerminal(f.Fd()) || isatty.IsCygwinTerminal(f.Fd())
+}