fix incorrect ErrConnectFailed comparison

xuzhenglun · vieux · commit ca51b2bf2c5b · 2016-11-22T11:23:49.000-08:00
Signed-off-by: Reficul <xuzhenglun@gmail.com> (cherry picked from commit d5dc9b8) Signed-off-by: Victor Vieux <victorvieux@gmail.com>
diff --git a/cli/command/container/exec.go b/cli/command/container/exec.go
@@ -170,7 +170,7 @@ func getExecExitCode(ctx context.Context, client apiclient.ContainerAPIClient, e
 	resp, err := client.ContainerExecInspect(ctx, execID)
 	if err != nil {
 		// If we can't connect, then the daemon probably died.
-		if err != apiclient.ErrConnectionFailed {
+		if !apiclient.IsErrConnectionFailed(err) {
 			return false, -1, err
 		}
 		return false, -1, nil
diff --git a/cli/command/container/utils.go b/cli/command/container/utils.go
@@ -102,7 +102,7 @@ func getExitCode(dockerCli *command.DockerCli, ctx context.Context, containerID
 	c, err := dockerCli.Client().ContainerInspect(ctx, containerID)
 	if err != nil {
 		// If we can't connect, then the daemon probably died.
-		if err != clientapi.ErrConnectionFailed {
+		if !clientapi.IsErrConnectionFailed(err) {
 			return false, -1, err
 		}
 		return false, -1, nil
diff --git a/client/errors.go b/client/errors.go
@@ -1,18 +1,34 @@
 package client
 
 import (
-	"errors"
 	"fmt"
 
 	"github.com/docker/docker/api/types/versions"
+	"github.com/pkg/errors"
 )
 
-// ErrConnectionFailed is an error raised when the connection between the client and the server failed.
-var ErrConnectionFailed = errors.New("Cannot connect to the Docker daemon. Is the docker daemon running on this host?")
+// errConnectionFailed implements an error returned when connection failed.
+type errConnectionFailed struct {
+	host string
+}
+
+// Error returns a string representation of an errConnectionFailed
+func (err errConnectionFailed) Error() string {
+	if err.host == "" {
+		return "Cannot connect to the Docker daemon. Is the docker daemon running on this host?"
+	}
+	return fmt.Sprintf("Cannot connect to the Docker daemon at %s. Is the docker daemon running?", err.host)
+}
+
+// IsErrConnectionFailed returns true if the error is caused by connection failed.
+func IsErrConnectionFailed(err error) bool {
+	_, ok := errors.Cause(err).(errConnectionFailed)
+	return ok
+}
 
 // ErrorConnectionFailed returns an error with host in the error message when connection to docker daemon failed.
 func ErrorConnectionFailed(host string) error {
-	return fmt.Errorf("Cannot connect to the Docker daemon at %s. Is the docker daemon running?", host)
+	return errConnectionFailed{host: host}
 }
 
 type notFound interface {

Original file line number	Diff line number	Diff line change
`@@ -170,7 +170,7 @@ func getExecExitCode(ctx context.Context, client apiclient.ContainerAPIClient, e`
`170`	`170`	`resp, err := client.ContainerExecInspect(ctx, execID)`
`171`	`171`	`if err != nil {`
`172`	`172`	`// If we can't connect, then the daemon probably died.`
`173`		`- if err != apiclient.ErrConnectionFailed {`
	`173`	`+ if !apiclient.IsErrConnectionFailed(err) {`
`174`	`174`	`return false, -1, err`
`175`	`175`	`}`
`176`	`176`	`return false, -1, nil`
Original file line number	Diff line number	Diff line change
`@@ -102,7 +102,7 @@ func getExitCode(dockerCli *command.DockerCli, ctx context.Context, containerID`
`102`	`102`	`c, err := dockerCli.Client().ContainerInspect(ctx, containerID)`
`103`	`103`	`if err != nil {`
`104`	`104`	`// If we can't connect, then the daemon probably died.`
`105`		`- if err != clientapi.ErrConnectionFailed {`
	`105`	`+ if !clientapi.IsErrConnectionFailed(err) {`
`106`	`106`	`return false, -1, err`
`107`	`107`	`}`
`108`	`108`	`return false, -1, nil`