Use log package

Author: jwilder

docker-gen.go

@@ -5,6 +5,7 @@ import (
 	"flag"
 	"fmt"
 	"io"
+	"log"
 	"net"
 	"net/http"
 	"net/http/httputil"
@@ -137,20 +138,20 @@ func getEvents() chan *Event {
 
 		c, err := newConn()
 		if err != nil {
-			fmt.Printf("cannot connect to docker: %s\n", err)
+			log.Printf("cannot connect to docker: %s\n", err)
 			return
 		}
 		defer c.Close()
 
 		req, err := http.NewRequest("GET", "/events", nil)
 		if err != nil {
-			fmt.Printf("bad request for events: %s\n", err)
+			log.Printf("bad request for events: %s\n", err)
 			return
 		}
 
 		resp, err := c.Do(req)
 		if err != nil {
-			fmt.Printf("cannot connect to events endpoint: %s\n", err)
+			log.Printf("cannot connect to events endpoint: %s\n", err)
 			return
 		}
 		defer resp.Body.Close()
@@ -160,7 +161,7 @@ func getEvents() chan *Event {
 		signal.Notify(sigChan, os.Interrupt, syscall.SIGTERM, syscall.SIGQUIT)
 		go func() {
 			for sig := range sigChan {
-				fmt.Printf("received signal '%v', exiting\n", sig)
+				log.Printf("received signal '%v', exiting\n", sig)
 
 				c.Close()
 				close(eventChan)
@@ -175,12 +176,12 @@ func getEvents() chan *Event {
 				if err == io.EOF {
 					break
 				}
-				fmt.Printf("cannot decode json: %s\n", err)
+				log.Printf("cannot decode json: %s\n", err)
 				goto restart
 			}
 			eventChan <- event
 		}
-		fmt.Printf("closing event channel\n")
+		log.Printf("closing event channel\n")
 	}()
 	return eventChan
 }
@@ -197,7 +198,7 @@ func getContainers(client *docker.Client) ([]*RuntimeContainer, error) {
 	for _, apiContainer := range apiContainers {
 		container, err := client.InspectContainer(apiContainer.ID)
 		if err != nil {
-			fmt.Printf("error inspecting container: %s: %s\n", apiContainer.ID, err)
+			log.Printf("error inspecting container: %s: %s\n", apiContainer.ID, err)
 			continue
 		}
 
@@ -233,7 +234,7 @@ func getContainers(client *docker.Client) ([]*RuntimeContainer, error) {
 func generateFromContainers(client *docker.Client) {
 	containers, err := getContainers(client)
 	if err != nil {
-		fmt.Printf("error listing containers: %s\n", err)
+		log.Printf("error listing containers: %s\n", err)
 		return
 	}
 	for _, config := range configs.Config {
@@ -253,7 +254,7 @@ func runNotifyCmd(config Config) {
 	cmd := exec.Command(args[0], args[1:]...)
 	out, err := cmd.CombinedOutput()
 	if err != nil {
-		fmt.Printf("error running notify command: %s, %s\n", config.NotifyCmd, err)
+		log.Printf("error running notify command: %s, %s\n", config.NotifyCmd, err)
 		fmt.Println(string(out))
 	}
 }
@@ -284,7 +285,7 @@ func generateAtInterval(client *docker.Client, configs ConfigFile) {
 				case <-ticker.C:
 					containers, err := getContainers(client)
 					if err != nil {
-						fmt.Printf("error listing containers: %s\n", err)
+						log.Printf("error listing containers: %s\n", err)
 						continue
 					}
 					// ignore changed return value. always run notify command
@@ -334,7 +335,7 @@ func main() {
 	if configFile != "" {
 		err := loadConfig(configFile)
 		if err != nil {
-			fmt.Printf("error loading config %s: %s\n", configFile, err)
+			log.Printf("error loading config %s: %s\n", configFile, err)
 			os.Exit(1)
 		}
 	} else {

reflect.go

@@ -1,7 +1,7 @@
 package main
 
 import (
-	"fmt"
+	"log"
 	"reflect"
 	"strings"
 )
@@ -40,7 +40,7 @@ func deepGet(item interface{}, path string) interface{} {
 				return deepGet(mapValue.Interface(), strings.Join(parts[1:], "."))
 			}
 		default:
-			fmt.Printf("can't group by %s\n", path)
+			log.Printf("can't group by %s\n", path)
 		}
 		return nil
 	}

template.go

@@ -2,9 +2,9 @@ package main
 
 import (
 	"bytes"
-	"fmt"
 	"io"
 	"io/ioutil"
+	"log"
 	"os"
 	"path/filepath"
 	"strings"
@@ -37,7 +37,7 @@ func generateFile(config Config, containers []*RuntimeContainer) bool {
 		"split":    strings.Split,
 	}).ParseFiles(templatePath)
 	if err != nil {
-		panic(err)
+		log.Fatalf("unable to parse template: %s", err)
 	}
 
 	filteredContainers := []*RuntimeContainer{}
@@ -59,16 +59,15 @@ func generateFile(config Config, containers []*RuntimeContainer) bool {
 			os.Remove(dest.Name())
 		}()
 		if err != nil {
-			fmt.Printf("unable to create temp file: %s\n", err)
-			os.Exit(1)
+			log.Fatalf("unable to create temp file: %s\n", err)
 		}
 	}
 
 	var buf bytes.Buffer
 	multiwriter := io.MultiWriter(dest, &buf)
 	err = tmpl.ExecuteTemplate(multiwriter, filepath.Base(templatePath), containers)
 	if err != nil {
-		fmt.Printf("template error: %s\n", err)
+		log.Fatalf("template error: %s\n", err)
 	}
 
 	if config.Dest != "" {
@@ -77,16 +76,14 @@ func generateFile(config Config, containers []*RuntimeContainer) bool {
 		if _, err := os.Stat(config.Dest); err == nil {
 			contents, err = ioutil.ReadFile(config.Dest)
 			if err != nil {
-				fmt.Printf("unable to compare current file contents: %s: %s\n", config.Dest, err)
-				os.Exit(1)
+				log.Fatalf("unable to compare current file contents: %s: %s\n", config.Dest, err)
 			}
 		}
 
 		if bytes.Compare(contents, buf.Bytes()) != 0 {
 			err = os.Rename(dest.Name(), config.Dest)
 			if err != nil {
-				fmt.Printf("unable to create dest file %s: %s\n", config.Dest, err)
-				os.Exit(1)
+				log.Fatalf("unable to create dest file %s: %s\n", config.Dest, err)
 			}
 			return true
 		}