Make kubectl commands return errors and centralize exit handling

pkg/kubectl/cmd/clusterinfo.go

@@ -34,20 +34,25 @@ func (f *Factory) NewCmdClusterInfo(out io.Writer) *cobra.Command {
 		Short: "Display cluster info",
 		Long:  "Display addresses of the master and services with label kubernetes.io/cluster-service=true",
 		Run: func(cmd *cobra.Command, args []string) {
-			RunClusterInfo(f, out, cmd)
+			err := RunClusterInfo(f, out, cmd)
+			util.CheckErr(err)
 		},
 	}
 	return cmd
 }
 
-func RunClusterInfo(factory *Factory, out io.Writer, cmd *cobra.Command) {
+func RunClusterInfo(factory *Factory, out io.Writer, cmd *cobra.Command) error {
 	client, err := factory.ClientConfig(cmd)
-	util.CheckErr(err)
+	if err != nil {
+		return err
+	}
 	fmt.Fprintf(out, "Kubernetes master is running at %v\n", client.Host)
 
 	mapper, typer := factory.Object(cmd)
 	cmdNamespace, err := factory.DefaultNamespace(cmd)
-	util.CheckErr(err)
+	if err != nil {
+		return err
+	}
 
 	// TODO: use generalized labels once they are implemented (#341)
 	b := resource.NewBuilder(mapper, typer, factory.ClientMapperForCommand(cmd)).
@@ -68,6 +73,7 @@ func RunClusterInfo(factory *Factory, out io.Writer, cmd *cobra.Command) {
 		}
 		return nil
 	})
+	return nil
 
 	// TODO: consider printing more information about cluster
 }

pkg/kubectl/cmd/cmd.go

@@ -34,7 +34,6 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 
-	"github.com/golang/glog"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 )
@@ -253,7 +252,9 @@ func (f *Factory) PrinterForMapping(cmd *cobra.Command, mapping *meta.RESTMappin
 	}
 	if ok {
 		clientConfig, err := f.ClientConfig(cmd)
-		cmdutil.CheckErr(err)
+		if err != nil {
+			return nil, err
+		}
 		defaultVersion := clientConfig.Version
 
 		version := cmdutil.OutputVersion(cmd, defaultVersion)
@@ -329,12 +330,6 @@ func DefaultClientConfig(flags *pflag.FlagSet) clientcmd.ClientConfig {
 	return clientConfig
 }
 
-func usageError(cmd *cobra.Command, format string, args ...interface{}) {
-	glog.Errorf(format, args...)
-	glog.Errorf("See '%s -h' for help.", cmd.CommandPath())
-	os.Exit(1)
-}
-
 func runHelp(cmd *cobra.Command, args []string) {
 	cmd.Help()
 }

pkg/kubectl/cmd/create.go

@@ -39,54 +39,67 @@ $ cat pod.json | kubectl create -f -`
 )
 
 func (f *Factory) NewCmdCreate(out io.Writer) *cobra.Command {
-	flags := &struct {
-		Filenames util.StringList
-	}{}
+	var filenames util.StringList
 	cmd := &cobra.Command{
 		Use:     "create -f filename",
 		Short:   "Create a resource by filename or stdin",
 		Long:    create_long,
 		Example: create_example,
 		Run: func(cmd *cobra.Command, args []string) {
-			schema, err := f.Validator(cmd)
+			err := RunCreate(f, out, cmd, filenames)
 			cmdutil.CheckErr(err)
+		},
+	}
+	cmd.Flags().VarP(&filenames, "filename", "f", "Filename, directory, or URL to file to use to create the resource")
+	return cmd
+}
 
-			cmdNamespace, err := f.DefaultNamespace(cmd)
-			cmdutil.CheckErr(err)
+func RunCreate(f *Factory, out io.Writer, cmd *cobra.Command, filenames util.StringList) error {
+	schema, err := f.Validator(cmd)
+	if err != nil {
+		return err
+	}
 
-			mapper, typer := f.Object(cmd)
-			r := resource.NewBuilder(mapper, typer, f.ClientMapperForCommand(cmd)).
-				ContinueOnError().
-				NamespaceParam(cmdNamespace).RequireNamespace().
-				FilenameParam(flags.Filenames...).
-				Flatten().
-				Do()
-			cmdutil.CheckErr(r.Err())
+	cmdNamespace, err := f.DefaultNamespace(cmd)
+	if err != nil {
+		return err
+	}
 
-			count := 0
-			err = r.Visit(func(info *resource.Info) error {
-				data, err := info.Mapping.Codec.Encode(info.Object)
-				if err != nil {
-					return err
-				}
-				if err := schema.ValidateBytes(data); err != nil {
-					return err
-				}
-				obj, err := resource.NewHelper(info.Client, info.Mapping).Create(info.Namespace, true, data)
-				if err != nil {
-					return err
-				}
-				count++
-				info.Refresh(obj, true)
-				fmt.Fprintf(out, "%s\n", info.Name)
-				return nil
-			})
-			cmdutil.CheckErr(err)
-			if count == 0 {
-				cmdutil.CheckErr(fmt.Errorf("no objects passed to create"))
-			}
-		},
+	mapper, typer := f.Object(cmd)
+	r := resource.NewBuilder(mapper, typer, f.ClientMapperForCommand(cmd)).
+		ContinueOnError().
+		NamespaceParam(cmdNamespace).RequireNamespace().
+		FilenameParam(filenames...).
+		Flatten().
+		Do()
+	err = r.Err()
+	if err != nil {
+		return err
 	}
-	cmd.Flags().VarP(&flags.Filenames, "filename", "f", "Filename, directory, or URL to file to use to create the resource")
-	return cmd
+
+	count := 0
+	err = r.Visit(func(info *resource.Info) error {
+		data, err := info.Mapping.Codec.Encode(info.Object)
+		if err != nil {
+			return err
+		}
+		if err := schema.ValidateBytes(data); err != nil {
+			return err
+		}
+		obj, err := resource.NewHelper(info.Client, info.Mapping).Create(info.Namespace, true, data)
+		if err != nil {
+			return err
+		}
+		count++
+		info.Refresh(obj, true)
+		fmt.Fprintf(out, "%s\n", info.Name)
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+	if count == 0 {
+		return fmt.Errorf("no objects passed to create")
+	}
+	return nil
 }

pkg/kubectl/cmd/delete.go

@@ -56,46 +56,57 @@ $ kubectl delete pods --all`
 )
 
 func (f *Factory) NewCmdDelete(out io.Writer) *cobra.Command {
-	flags := &struct {
-		Filenames util.StringList
-	}{}
+	var filenames util.StringList
 	cmd := &cobra.Command{
 		Use:     "delete ([-f filename] | (<resource> [(<id> | -l <label> | --all)]",
 		Short:   "Delete a resource by filename, stdin, or resource and ID.",
 		Long:    delete_long,
 		Example: delete_example,
 		Run: func(cmd *cobra.Command, args []string) {
-			cmdNamespace, err := f.DefaultNamespace(cmd)
+			err := RunDelete(f, out, cmd, args, filenames)
 			cmdutil.CheckErr(err)
-			mapper, typer := f.Object(cmd)
-			r := resource.NewBuilder(mapper, typer, f.ClientMapperForCommand(cmd)).
-				ContinueOnError().
-				NamespaceParam(cmdNamespace).DefaultNamespace().
-				FilenameParam(flags.Filenames...).
-				SelectorParam(cmdutil.GetFlagString(cmd, "selector")).
-				SelectAllParam(cmdutil.GetFlagBool(cmd, "all")).
-				ResourceTypeOrNameArgs(false, args...).
-				Flatten().
-				Do()
-			cmdutil.CheckErr(r.Err())
-
-			found := 0
-			err = r.IgnoreErrors(errors.IsNotFound).Visit(func(r *resource.Info) error {
-				found++
-				if err := resource.NewHelper(r.Client, r.Mapping).Delete(r.Namespace, r.Name); err != nil {
-					return err
-				}
-				fmt.Fprintf(out, "%s\n", r.Name)
-				return nil
-			})
-			cmdutil.CheckErr(err)
-			if found == 0 {
-				fmt.Fprintf(cmd.Out(), "No resources found\n")
-			}
 		},
 	}
-	cmd.Flags().VarP(&flags.Filenames, "filename", "f", "Filename, directory, or URL to a file containing the resource to delete")
+	cmd.Flags().VarP(&filenames, "filename", "f", "Filename, directory, or URL to a file containing the resource to delete")
 	cmd.Flags().StringP("selector", "l", "", "Selector (label query) to filter on")
 	cmd.Flags().Bool("all", false, "[-all] to select all the specified resources")
 	return cmd
 }
+
+func RunDelete(f *Factory, out io.Writer, cmd *cobra.Command, args []string, filenames util.StringList) error {
+	cmdNamespace, err := f.DefaultNamespace(cmd)
+	if err != nil {
+		return err
+	}
+	mapper, typer := f.Object(cmd)
+	r := resource.NewBuilder(mapper, typer, f.ClientMapperForCommand(cmd)).
+		ContinueOnError().
+		NamespaceParam(cmdNamespace).DefaultNamespace().
+		FilenameParam(filenames...).
+		SelectorParam(cmdutil.GetFlagString(cmd, "selector")).
+		SelectAllParam(cmdutil.GetFlagBool(cmd, "all")).
+		ResourceTypeOrNameArgs(false, args...).
+		Flatten().
+		Do()
+	err = r.Err()
+	if err != nil {
+		return err
+	}
+
+	found := 0
+	err = r.IgnoreErrors(errors.IsNotFound).Visit(func(r *resource.Info) error {
+		found++
+		if err := resource.NewHelper(r.Client, r.Mapping).Delete(r.Namespace, r.Name); err != nil {
+			return err
+		}
+		fmt.Fprintf(out, "%s\n", r.Name)
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+	if found == 0 {
+		fmt.Fprintf(cmd.Out(), "No resources found\n")
+	}
+	return nil
+}

pkg/kubectl/cmd/describe.go

@@ -33,20 +33,35 @@ func (f *Factory) NewCmdDescribe(out io.Writer) *cobra.Command {
 This command joins many API calls together to form a detailed description of a
 given resource.`,
 		Run: func(cmd *cobra.Command, args []string) {
-			cmdNamespace, err := f.DefaultNamespace(cmd)
+			err := RunDescribe(f, out, cmd, args)
 			util.CheckErr(err)
+		},
+	}
+	return cmd
+}
 
-			mapper, _ := f.Object(cmd)
-			// TODO: use resource.Builder instead
-			mapping, namespace, name := util.ResourceFromArgs(cmd, args, mapper, cmdNamespace)
+func RunDescribe(f *Factory, out io.Writer, cmd *cobra.Command, args []string) error {
+	cmdNamespace, err := f.DefaultNamespace(cmd)
+	if err != nil {
+		return err
+	}
 
-			describer, err := f.Describer(cmd, mapping)
-			util.CheckErr(err)
+	mapper, _ := f.Object(cmd)
+	// TODO: use resource.Builder instead
+	mapping, namespace, name, err := util.ResourceFromArgs(cmd, args, mapper, cmdNamespace)
+	if err != nil {
+		return err
+	}
 
-			s, err := describer.Describe(namespace, name)
-			util.CheckErr(err)
-			fmt.Fprintf(out, "%s\n", s)
-		},
+	describer, err := f.Describer(cmd, mapping)
+	if err != nil {
+		return err
 	}
-	return cmd
+
+	s, err := describer.Describe(namespace, name)
+	if err != nil {
+		return err
+	}
+	fmt.Fprintf(out, "%s\n", s)
+	return nil
 }