add docker-image command for backwards compatibility

Author: Blaimi

pkg/cmd/kind/load/docker-image/docker-image.go

@@ -0,0 +1,266 @@
+/*
+Copyright 2019 The Kubernetes 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 load
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/spf13/cobra"
+
+	"sigs.k8s.io/kind/pkg/cluster"
+	"sigs.k8s.io/kind/pkg/cluster/nodes"
+	"sigs.k8s.io/kind/pkg/cluster/nodeutils"
+	"sigs.k8s.io/kind/pkg/cmd"
+	"sigs.k8s.io/kind/pkg/errors"
+	"sigs.k8s.io/kind/pkg/fs"
+	"sigs.k8s.io/kind/pkg/log"
+
+	"sigs.k8s.io/kind/pkg/internal/cli"
+	"sigs.k8s.io/kind/pkg/internal/runtime"
+)
+
+type (
+	imageTagFetcher func(nodes.Node, string) (map[string]bool, error)
+)
+
+type flagpole struct {
+	Name  string
+	Nodes []string
+}
+
+// NewCommand returns a new cobra.Command for loading an image into a cluster
+func NewCommand(logger log.Logger, streams cmd.IOStreams) *cobra.Command {
+	flags := &flagpole{}
+	cmd := &cobra.Command{
+		Args: func(cmd *cobra.Command, args []string) error {
+			if len(args) < 1 {
+				return errors.New("a list of image names is required")
+			}
+			return nil
+		},
+		Use:        "docker-image <IMAGE> [IMAGE...]",
+		Short:      "Loads docker images from host into nodes",
+		Long:       "Loads docker images from host into all or specified nodes by name",
+		Deprecated: "Please use 'kind load container-image' instead of 'kind load docker-image', 'docker-image' will be removed in future releases and is restricted to load images from docker.",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			cli.OverrideDefaultName(cmd.Flags())
+			return runE(logger, flags, args)
+		},
+	}
+	cmd.Flags().StringVarP(
+		&flags.Name,
+		"name",
+		"n",
+		cluster.DefaultName,
+		"the cluster context name",
+	)
+	cmd.Flags().StringSliceVar(
+		&flags.Nodes,
+		"nodes",
+		nil,
+		"comma separated list of nodes to load images into",
+	)
+	return cmd
+}
+
+func runE(logger log.Logger, flags *flagpole, args []string) error {
+	provider := cluster.NewProvider(
+		cluster.ProviderWithLogger(logger),
+		runtime.GetDefault(logger),
+	)
+
+	saveProvider := cluster.NewProvider(
+		cluster.ProviderWithDocker(),
+		runtime.GetDefault(logger),
+	)
+
+	// Check that the image exists locally and gets its ID, if not return error
+	imageNames := removeDuplicates(args)
+	var imageIDs []string
+	for _, imageName := range imageNames {
+		imageID, err := saveProvider.ContainerImageID(imageName)
+		if err != nil {
+			return fmt.Errorf("image: %q not present locally", imageName)
+		}
+		imageIDs = append(imageIDs, imageID)
+	}
+
+	// Check if the cluster nodes exist
+	nodeList, err := provider.ListInternalNodes(flags.Name)
+	if err != nil {
+		return err
+	}
+	if len(nodeList) == 0 {
+		return fmt.Errorf("no nodes found for cluster %q", flags.Name)
+	}
+
+	// map cluster nodes by their name
+	nodesByName := map[string]nodes.Node{}
+	for _, node := range nodeList {
+		// TODO(bentheelder): this depends on the fact that ListByCluster()
+		// will have name for nameOrId.
+		nodesByName[node.String()] = node
+	}
+
+	// pick only the user selected nodes and ensure they exist
+	// the default is all nodes unless flags.Nodes is set
+	candidateNodes := nodeList
+	if len(flags.Nodes) > 0 {
+		candidateNodes = []nodes.Node{}
+		for _, name := range flags.Nodes {
+			node, ok := nodesByName[name]
+			if !ok {
+				return fmt.Errorf("unknown node: %q", name)
+			}
+			candidateNodes = append(candidateNodes, node)
+		}
+	}
+
+	// pick only the nodes that don't have the image
+	selectedNodes := map[string]nodes.Node{}
+	fns := []func() error{}
+	for i, imageName := range imageNames {
+		imageID := imageIDs[i]
+		processed := false
+		for _, node := range candidateNodes {
+			exists, reTagRequired, sanitizedImageName := checkIfImageReTagRequired(node, imageID, imageName, nodeutils.ImageTags)
+			if exists && !reTagRequired {
+				continue
+			}
+
+			if reTagRequired {
+				// We will try to re-tag the image. If the re-tag fails, we will fall back to the default behavior of loading
+				// the images into the nodes again
+				logger.V(0).Infof("Image with ID: %s already present on the node %s but is missing the tag %s. re-tagging...", imageID, node.String(), sanitizedImageName)
+				if err := nodeutils.ReTagImage(node, imageID, sanitizedImageName); err != nil {
+					logger.Errorf("failed to re-tag image on the node %s due to an error %s. Will load it instead...", node.String(), err)
+					selectedNodes[node.String()] = node
+				} else {
+					processed = true
+				}
+				continue
+			}
+			id, err := nodeutils.ImageID(node, imageName)
+			if err != nil || id != imageID {
+				selectedNodes[node.String()] = node
+				logger.V(0).Infof("Image: %q with ID %q not yet present on node %q, loading...", imageName, imageID, node.String())
+			}
+			continue
+		}
+		if len(selectedNodes) == 0 && !processed {
+			logger.V(0).Infof("Image: %q with ID %q found to be already present on all nodes.", imageName, imageID)
+		}
+	}
+
+	// return early if no node needs the image
+	if len(selectedNodes) == 0 {
+		return nil
+	}
+
+	// Setup the tar path where the images will be saved
+	dir, err := fs.TempDir("", "images-tar")
+	if err != nil {
+		return errors.Wrap(err, "failed to create tempdir")
+	}
+	defer os.RemoveAll(dir)
+	imagesTarPath := filepath.Join(dir, "images.tar")
+	// Save the images into a tar
+	err = saveProvider.ContainerSave(imageNames, imagesTarPath)
+	if err != nil {
+		return err
+	}
+
+	// Load the images on the selected nodes
+	for _, selectedNode := range selectedNodes {
+		selectedNode := selectedNode // capture loop variable
+		fns = append(fns, func() error {
+			return loadImage(imagesTarPath, selectedNode)
+		})
+	}
+	return errors.UntilErrorConcurrent(fns)
+}
+
+// TODO: we should consider having a cluster method to load images
+
+// loads an image tarball onto a node
+func loadImage(imageTarName string, node nodes.Node) error {
+	f, err := os.Open(imageTarName)
+	if err != nil {
+		return errors.Wrap(err, "failed to open image")
+	}
+	defer f.Close()
+	return nodeutils.LoadImageArchive(node, f)
+}
+
+// removeDuplicates removes duplicates from a string slice
+func removeDuplicates(slice []string) []string {
+	result := []string{}
+	seenKeys := make(map[string]struct{})
+	for _, k := range slice {
+		if _, seen := seenKeys[k]; !seen {
+			result = append(result, k)
+			seenKeys[k] = struct{}{}
+		}
+	}
+	return result
+}
+
+// checkIfImageExists makes sure we only perform the reverse lookup of the ImageID to tag map
+func checkIfImageReTagRequired(node nodes.Node, imageID, imageName string, tagFetcher imageTagFetcher) (exists, reTagRequired bool, sanitizedImage string) {
+	tags, err := tagFetcher(node, imageID)
+	if len(tags) == 0 || err != nil {
+		exists = false
+		return
+	}
+	exists = true
+	sanitizedImage = sanitizeImage(imageName)
+	if ok := tags[sanitizedImage]; ok {
+		reTagRequired = false
+		return
+	}
+	reTagRequired = true
+	return
+}
+
+// sanitizeImage is a helper to return human readable image name
+// This is a modified version of the same function found under providers/podman/images.go
+func sanitizeImage(image string) (sanitizedName string) {
+	const (
+		defaultDomain    = "docker.io/"
+		officialRepoName = "library"
+	)
+	sanitizedName = image
+
+	if !strings.ContainsRune(image, '/') {
+		sanitizedName = officialRepoName + "/" + image
+	}
+
+	i := strings.IndexRune(sanitizedName, '/')
+	if i == -1 || (!strings.ContainsAny(sanitizedName[:i], ".:") && sanitizedName[:i] != "localhost") {
+		sanitizedName = defaultDomain + sanitizedName
+	}
+
+	i = strings.IndexRune(sanitizedName, ':')
+	if i == -1 {
+		sanitizedName += ":latest"
+	}
+
+	return
+}

pkg/cmd/kind/load/load.go

@@ -24,6 +24,7 @@ import (
 
 	"sigs.k8s.io/kind/pkg/cmd"
 	containerimage "sigs.k8s.io/kind/pkg/cmd/kind/load/container-image"
+	dockerimage "sigs.k8s.io/kind/pkg/cmd/kind/load/docker-image"
 	imagearchive "sigs.k8s.io/kind/pkg/cmd/kind/load/image-archive"
 	"sigs.k8s.io/kind/pkg/log"
 )
@@ -45,6 +46,7 @@ func NewCommand(logger log.Logger, streams cmd.IOStreams) *cobra.Command {
 	}
 	// add subcommands
 	cmd.AddCommand(containerimage.NewCommand(logger, streams))
+	cmd.AddCommand(dockerimage.NewCommand(logger, streams))
 	cmd.AddCommand(imagearchive.NewCommand(logger, streams))
 	return cmd
 }