fix: use base names for source files in log messages; colorize

internal/log/color.go

@@ -0,0 +1,33 @@
+package log
+
+import (
+	"fmt"
+	"os"
+)
+
+const (
+	colorBlack = iota + 30
+	colorRed
+	colorGreen
+	colorYellow
+	colorBlue
+	colorMagenta
+	colorCyan
+	colorWhite
+
+	colorBold     = 1
+	colorDarkGray = 90
+)
+
+// colorize returns the string s wrapped in ANSI code c, unless disabled is true or c is 0.
+func colorize(s interface{}, c int, disabled bool) string {
+	e := os.Getenv("NO_COLOR")
+	if e != "" || c == 0 {
+		disabled = true
+	}
+
+	if disabled {
+		return fmt.Sprintf("%s", s)
+	}
+	return fmt.Sprintf("\x1b[%dm%v\x1b[0m", c, s)
+}

internal/log/log.go

@@ -3,6 +3,9 @@ package log
 import (
 	"fmt"
 	"os"
+	"path/filepath"
+	"regexp"
+	"runtime"
 	"strings"
 	"time"
 
@@ -28,24 +31,44 @@ func Init(ll, lf string) error {
 		return fmt.Errorf("unknown log level: %s", ll)
 	}
 
+	cw := zerolog.ConsoleWriter{Out: os.Stderr}
 	switch lf {
 	case "rfc3339":
-		Logger = zerolog.New(
-			zerolog.ConsoleWriter{Out: os.Stderr, TimeFormat: time.RFC3339},
-		).Level(loggerLevel).With().Timestamp().Caller().Logger()
+		cw.TimeFormat = time.RFC3339
+		cw.FormatCaller = getFormatCaller(cw.NoColor)
+		Logger = zerolog.New(cw).Level(loggerLevel).With().Timestamp().Caller().Logger()
 	case "basic":
-		Logger = zerolog.New(
-			zerolog.ConsoleWriter{
-				Out:             os.Stderr,
-				FormatTimestamp: func(i interface{}) string { return "" },
-				FormatLevel:     func(i interface{}) string { return strings.ToUpper(fmt.Sprintf("%-6s|", i)) },
-			},
-		).Level(loggerLevel).With().Caller().Logger()
+		cw.FormatTimestamp = func(i interface{}) string { return "" }
+		cw.FormatLevel = func(i interface{}) string { return strings.ToUpper(fmt.Sprintf("%-6s|", i)) }
+		cw.FormatCaller = getFormatCaller(cw.NoColor)
+		Logger = zerolog.New(cw).Level(loggerLevel).With().Caller().Logger()
 	case "json":
-		Logger = zerolog.New(os.Stderr).Level(loggerLevel).With().Timestamp().Logger()
+		Logger = zerolog.New(cw).Level(loggerLevel).With().Timestamp().Logger()
 	default:
 		return fmt.Errorf("unknown log format: %s", lf)
 	}
 
 	return nil
 }
+
+// getFormatCaller is a wrapper that generates a Formatter for the
+// ConsoleWriter.FormatCaller field. The Formatter generated uses the base name
+// of the source file where the log message originated from and ensures that it
+// is still colorized, if enabled.
+func getFormatCaller(noColor bool) zerolog.Formatter {
+	return func(i interface{}) string {
+		re := regexp.MustCompile(`(?P<path>.*):(?P<line>\d+)`)
+		path := re.ReplaceAllString(i.(string), "${path}")
+		line := re.ReplaceAllString(i.(string), "${line}")
+
+		var out string
+		_, f, l, ok := runtime.Caller(7)
+		if ok {
+			out = fmt.Sprintf("%s:%d", filepath.Base(f), l)
+		} else {
+			out = fmt.Sprintf("%s:%d", path, line)
+		}
+
+		return colorize(out, colorBold, noColor) + colorize(" >", colorCyan, noColor)
+	}
+}