Extract log utils into pkg/log

Docker-DCO-1.1-Signed-off-by: Josiah Kiehl <josiah@capoferro.net> (github: capoferro)

broadcastwriter/broadcastwriter.go

@@ -4,11 +4,11 @@ import (
 	"bytes"
 	"encoding/json"
 	"io"
-	"log"
 	"sync"
 	"time"
 
 	"github.com/docker/docker/pkg/jsonlog"
+	"github.com/docker/docker/pkg/log"
 )
 
 // BroadcastWriter accumulate multiple io.WriteCloser by stream.
@@ -56,7 +56,7 @@ func (w *BroadcastWriter) Write(p []byte) (n int, err error) {
 			}
 			b, err := json.Marshal(jsonlog.JSONLog{Log: line, Stream: stream, Created: created})
 			if err != nil {
-				log.Printf("Error making JSON log line: %s", err)
+				log.Errorf("Error making JSON log line: %s", err)
 				continue
 			}
 			b = append(b, '\n')

httputils/resumablerequestreader.go

@@ -3,9 +3,10 @@ package httputils
 import (
 	"fmt"
 	"io"
-	"log"
 	"net/http"
 	"time"
+
+	"github.com/docker/docker/pkg/log"
 )
 
 type resumableRequestReader struct {
@@ -71,7 +72,7 @@ func (r *resumableRequestReader) Read(p []byte) (n int, err error) {
 		r.cleanUpResponse()
 	}
 	if err != nil && err != io.EOF {
-		log.Printf("encountered error during pull and clearing it before resume: %s", err)
+		log.Infof("encountered error during pull and clearing it before resume: %s", err)
 		err = nil
 	}
 	return n, err

log/log.go

@@ -0,0 +1,77 @@
+package log
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"runtime"
+	"strings"
+)
+
+type priority int
+
+const (
+	errorFormat = "[%s] %s:%d %s\n"
+	logFormat   = "[%s] %s\n"
+
+	fatal priority = iota
+	error
+	info
+	debug
+)
+
+func (p priority) String() string {
+	switch p {
+	case fatal:
+		return "fatal"
+	case error:
+		return "error"
+	case info:
+		return "info"
+	case debug:
+		return "debug"
+	}
+
+	return ""
+}
+
+// Debug function, if the debug flag is set, then display. Do nothing otherwise
+// If Docker is in damon mode, also send the debug info on the socket
+func Debugf(format string, a ...interface{}) {
+	if os.Getenv("DEBUG") != "" {
+		logf(os.Stderr, debug, format, a...)
+	}
+}
+
+func Infof(format string, a ...interface{}) {
+	logf(os.Stdout, info, format, a...)
+}
+
+func Errorf(format string, a ...interface{}) {
+	logf(os.Stderr, error, format, a...)
+}
+
+func Fatalf(format string, a ...interface{}) {
+	logf(os.Stderr, fatal, format, a...)
+	os.Exit(1)
+}
+
+func logf(stream io.Writer, level priority, format string, a ...interface{}) {
+	var prefix string
+
+	if level <= error || level == debug {
+		// Retrieve the stack infos
+		_, file, line, ok := runtime.Caller(2)
+		if !ok {
+			file = "<unknown>"
+			line = -1
+		} else {
+			file = file[strings.LastIndex(file, "/")+1:]
+		}
+		prefix = fmt.Sprintf(errorFormat, level.String(), file, line, format)
+	} else {
+		prefix = fmt.Sprintf(logFormat, level.String(), format)
+	}
+
+	fmt.Fprintf(stream, prefix, a...)
+}

log/log_test.go

@@ -0,0 +1,37 @@
+package log
+
+import (
+	"bytes"
+	"regexp"
+
+	"testing"
+)
+
+func TestLogFatalf(t *testing.T) {
+	var output *bytes.Buffer
+
+	tests := []struct {
+		Level           priority
+		Format          string
+		Values          []interface{}
+		ExpectedPattern string
+	}{
+		{fatal, "%d + %d = %d", []interface{}{1, 1, 2}, "\\[fatal\\] testing.go:\\d+ 1 \\+ 1 = 2"},
+		{error, "%d + %d = %d", []interface{}{1, 1, 2}, "\\[error\\] testing.go:\\d+ 1 \\+ 1 = 2"},
+		{info, "%d + %d = %d", []interface{}{1, 1, 2}, "\\[info\\] 1 \\+ 1 = 2"},
+		{debug, "%d + %d = %d", []interface{}{1, 1, 2}, "\\[debug\\] testing.go:\\d+ 1 \\+ 1 = 2"},
+	}
+
+	for i, test := range tests {
+		output = &bytes.Buffer{}
+		logf(output, test.Level, test.Format, test.Values...)
+
+		expected := regexp.MustCompile(test.ExpectedPattern)
+		if !expected.MatchString(output.String()) {
+			t.Errorf("[%d] Log output does not match expected pattern:\n\tExpected: %s\n\tOutput: %s",
+				i,
+				expected.String(),
+				output.String())
+		}
+	}
+}

tarsum/tarsum.go

@@ -7,12 +7,13 @@ import (
 	"encoding/hex"
 	"hash"
 	"io"
-	"log"
 	"sort"
 	"strconv"
 	"strings"
 
 	"github.com/docker/docker/vendor/src/code.google.com/p/go/src/pkg/archive/tar"
+
+	"github.com/docker/docker/pkg/log"
 )
 
 type TarSum struct {
@@ -170,11 +171,11 @@ func (ts *TarSum) Sum(extra []byte) string {
 		h.Write(extra)
 	}
 	for _, sum := range sums {
-		log.Printf("-->%s<--", sum)
+		log.Infof("-->%s<--", sum)
 		h.Write([]byte(sum))
 	}
 	checksum := "tarsum+sha256:" + hex.EncodeToString(h.Sum(nil))
-	log.Printf("checksum processed: %s", checksum)
+	log.Infof("checksum processed: %s", checksum)
 	return checksum
 }