Merge pull request #3416 from crosbymichael/hard-code-err

Replace hard coded error messages

cmd/ctr/commands/containers/containers.go

@@ -30,7 +30,6 @@ import (
 	"github.com/containerd/containerd/containers"
 	"github.com/containerd/containerd/log"
 	"github.com/containerd/typeurl"
-	"github.com/pkg/errors"
 	"github.com/urfave/cli"
 )
 
@@ -65,17 +64,17 @@ var createCommand = cli.Command{
 		if config {
 			id = context.Args().First()
 			if context.NArg() > 1 {
-				return errors.New("with spec config file, only container id should be provided")
+				return commands.ErrArgConfigFile
 			}
 		} else {
 			id = context.Args().Get(1)
 			ref = context.Args().First()
 			if ref == "" {
-				return errors.New("image ref must be provided")
+				return commands.ErrUnprovidedImageRef
 			}
 		}
 		if id == "" {
-			return errors.New("container id must be provided")
+			return commands.ErrEmptyContainerID
 		}
 		client, ctx, cancel, err := commands.NewClient(context)
 		if err != nil {
@@ -168,7 +167,7 @@ var deleteCommand = cli.Command{
 		}
 
 		if context.NArg() == 0 {
-			return errors.New("must specify at least one container to delete")
+			return commands.ErrDeleteNoneContainer
 		}
 		for _, arg := range context.Args() {
 			if err := deleteContainer(ctx, client, arg, deleteOpts...); err != nil {
@@ -214,7 +213,7 @@ var setLabelsCommand = cli.Command{
 	Action: func(context *cli.Context) error {
 		containerID, labels := commands.ObjectWithLabelArgs(context)
 		if containerID == "" {
-			return errors.New("container id must be provided")
+			return commands.ErrEmptyContainerID
 		}
 		client, ctx, cancel, err := commands.NewClient(context)
 		if err != nil {
@@ -250,7 +249,7 @@ var infoCommand = cli.Command{
 	Action: func(context *cli.Context) error {
 		id := context.Args().First()
 		if id == "" {
-			return errors.New("container id must be provided")
+			return commands.ErrEmptyContainerID
 		}
 		client, ctx, cancel, err := commands.NewClient(context)
 		if err != nil {

cmd/ctr/commands/error.go

@@ -0,0 +1,32 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package commands
+
+import (
+	"github.com/pkg/errors"
+)
+
+var (
+	// ErrArgConfigFile is returned when the configuration for a spec is provided
+	ErrArgConfigFile = errors.New("with spec config file, only container id should be provided")
+	// ErrUnprovidedImageRef is returned when no image reference is provided
+	ErrUnprovidedImageRef = errors.New("image ref must be provided")
+	// ErrEmptyContainerID is returned when no container id is provided
+	ErrEmptyContainerID = errors.New("container id must be provided")
+	// ErrDeleteNoneContainer is returned when no container ids are provided for deletion
+	ErrDeleteNoneContainer = errors.New("must specify at least one container to delete")
+)