Merge pull request #905 from docker/fix_aci_potential_nil_panic

Use ACI .IsHttpStatus() rather than accessing .StatusCode directly

aci/aci.go

@@ -173,7 +173,7 @@ func stopACIContainerGroup(ctx context.Context, aciContext store.AciContext, con
 	}
 
 	result, err := containerGroupsClient.Stop(ctx, aciContext.ResourceGroup, containerGroupName)
-	if result.StatusCode == http.StatusNotFound {
+	if result.IsHTTPStatus(http.StatusNotFound) {
 		return errdefs.ErrNotFound
 	}
 	return err

aci/compose.go

@@ -62,7 +62,7 @@ func (cs *aciComposeService) Down(ctx context.Context, project string) error {
 	if err != nil {
 		return err
 	}
-	if cg.StatusCode == http.StatusNoContent {
+	if cg.IsHTTPStatus(http.StatusNoContent) {
 		return errdefs.ErrNotFound
 	}
 

aci/containers.go

@@ -223,7 +223,7 @@ func (cs *aciContainerService) Delete(ctx context.Context, containerID string, r
 
 	cg, err := deleteACIContainerGroup(ctx, cs.ctx, groupName)
 	// Delete returns `StatusNoContent` if the group is not found
-	if cg.StatusCode == http.StatusNoContent {
+	if cg.IsHTTPStatus(http.StatusNoContent) {
 		return errdefs.ErrNotFound
 	}
 	if err != nil {

aci/volumes.go

@@ -223,7 +223,7 @@ func (cs *aciVolumeService) Delete(ctx context.Context, id string, options inter
 		if err == nil {
 			if _, ok := account.Tags[dockerVolumeTag]; ok {
 				result, err := storageAccountsClient.Delete(ctx, cs.aciContext.ResourceGroup, storageAccount)
-				if result.StatusCode == http.StatusNoContent {
+				if result.IsHTTPStatus(http.StatusNoContent) {
 					return errors.Wrapf(errdefs.ErrNotFound, "storage account %s does not exist", storageAccount)
 				}
 				return err