tail: add more log types and support pipe to stdout/stderr

Signed-off-by: Christian Winther <[email protected]>

command/tail/color_log_writer.go

@@ -2,14 +2,14 @@ package tail
 
 import (
 	"bytes"
+	"fmt"
 	"io"
-	"strings"
+	"os"
 
 	"github.com/alecthomas/chroma"
 	"github.com/alecthomas/chroma/formatters"
 	"github.com/alecthomas/chroma/lexers"
 	"github.com/alecthomas/chroma/styles"
-	log "github.com/sirupsen/logrus"
 )
 
 type colorLogWriter struct {
@@ -18,7 +18,6 @@ type colorLogWriter struct {
 
 func (w colorLogWriter) Write(p []byte) (n int, err error) {
 	s := string(p)
-	s = strings.Trim(s, "\n")
 
 	if string(s[0]) == "{" {
 		buffer := bytes.NewBufferString("")
@@ -27,11 +26,9 @@ func (w colorLogWriter) Write(p []byte) (n int, err error) {
 	}
 
 	if w.Type == "stdout" {
-		log.Info(s)
-	} else if w.Type == "stderr" {
-		log.Error(s)
+		fmt.Fprintf(os.Stdout, s)
 	} else {
-		log.Warn(s)
+		fmt.Fprintf(os.Stderr, s)
 	}
 
 	return len(p), nil

command/tail/raw_log_writer.go

@@ -0,0 +1,22 @@
+package tail
+
+import (
+	"fmt"
+	"os"
+)
+
+type rawLogWriter struct {
+	Type string
+}
+
+func (w rawLogWriter) Write(p []byte) (n int, err error) {
+	s := string(p)
+
+	if w.Type == "stdout" {
+		fmt.Fprintf(os.Stdout, s)
+	} else {
+		fmt.Fprintf(os.Stderr, s)
+	}
+
+	return len(p), nil
+}

command/tail/simple_log_writer.go

@@ -1,9 +1,9 @@
 package tail
 
 import (
+	"fmt"
+	"os"
 	"strings"
-
-	log "github.com/sirupsen/logrus"
 )
 
 type simpleLogWriter struct {
@@ -15,11 +15,9 @@ func (w simpleLogWriter) Write(p []byte) (n int, err error) {
 	s = strings.Trim(s, "\n")
 
 	if w.Type == "stdout" {
-		log.Info(s)
-	} else if w.Type == "stderr" {
-		log.Error(s)
+		fmt.Fprintf(os.Stdout, s)
 	} else {
-		log.Warn(s)
+		fmt.Fprintf(os.Stderr, s)
 	}
 
 	return len(p), nil

command/tail/tail.go

@@ -52,13 +52,13 @@ func Run(c *cli.Context) error {
 	if c.BoolT("stdout") {
 		wg.Add(1)
 		logger := log.WithField("log_type", "stdout")
-		go Tail("stdout", taskName, alloc, nomadClient, &wg, logger)
+		go Tail(getWriter("stdout", c.String("writer")), "stderr", taskName, alloc, nomadClient, &wg, logger)
 	}
 
 	if c.BoolT("stderr") {
 		wg.Add(1)
 		logger := log.WithField("log_type", "stderr")
-		go Tail("stderr", taskName, alloc, nomadClient, &wg, logger)
+		go Tail(getWriter("stderr", c.String("writer")), "stdout", taskName, alloc, nomadClient, &wg, logger)
 	}
 
 	go func() {
@@ -76,7 +76,20 @@ func Run(c *cli.Context) error {
 	return nil
 }
 
-func Tail(logType, task string, alloc *api.Allocation, client *api.Client, wg *sync.WaitGroup, logger *log.Entry) {
+func getWriter(target, kind string) io.Writer {
+	switch kind {
+	case "color":
+		return colorLogWriter{Type: target}
+	case "simple":
+		return simpleLogWriter{Type: target}
+	case "raw":
+		return rawLogWriter{Type: target}
+	default:
+		panic("Invalid log ")
+	}
+}
+
+func Tail(wr io.Writer, logType, task string, alloc *api.Allocation, client *api.Client, wg *sync.WaitGroup, logger *log.Entry) {
 	var err error
 	var r io.ReadCloser
 	var readErr error
@@ -97,7 +110,7 @@ func Tail(logType, task string, alloc *api.Allocation, client *api.Client, wg *s
 	}
 
 	defer r.Close()
-	_, err = io.Copy(colorLogWriter{Type: logType}, r)
+	_, err = io.Copy(wr, r)
 	if err != nil {
 		logger.Error(fmt.Sprintf("error following logs: %s", err))
 		return

main.go

@@ -121,6 +121,11 @@ func main() {
 					Name:  "stdout",
 					Usage: "(optional, default: true) tail stdout from nomad",
 				},
+				cli.StringFlag{
+					Name:  "writer",
+					Value: "color",
+					Usage: "(optional, default: color) writer type (raw, color, simple)",
+				},
 			},
 			Action: func(c *cli.Context) error {
 				if err := tail.Run(c); err != nil {