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load add image-load, support podman load
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Signed-off-by: helen <[email protected]>
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helen committed Feb 23, 2023
1 parent 6b58c9d commit 7607f6b
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2 changes: 1 addition & 1 deletion Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -65,7 +65,7 @@ KIND_BUILD_FLAGS?=-trimpath -ldflags="-buildid= -w $(KIND_BUILD_LD_FLAGS)"
all: build
# builds kind in a container, outputs to $(OUT_DIR)
kind:
go build -v -o "$(OUT_DIR)/$(KIND_BINARY_NAME)" $(KIND_BUILD_FLAGS)
GOOS=linux GOARCH=amd64 go build -v -o "$(OUT_DIR)/$(KIND_BINARY_NAME)" $(KIND_BUILD_FLAGS)
# alias for building kind
build: kind
# use: make install INSTALL_DIR=/usr/local/bin
Expand Down
305 changes: 305 additions & 0 deletions pkg/cmd/kind/load/image-load/image-load.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,305 @@
/*
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 implements the `load` command
package load

import (
syserrors "errors"
"fmt"
"os"
osexec "os/exec"
"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/exec"
"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: "image-load <IMAGE> [IMAGE...]",
Short: "Loads images from host into nodes",
Long: "Loads images from host into all or specified nodes by name",
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),
)

runtimePath, err := GetDefaultRuntime()
if err != nil {
return err
}
// 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 := imageID(runtimePath, 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 = save(runtimePath, 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)
}

// save saves images to dest
func save(binary string, images []string, dest string) error {
commandArgs := append([]string{"save", "-o", dest}, images...)
return exec.Command(binary, commandArgs...).Run()
}

// imageID return the Id of the container image
func imageID(binary, containerNameOrID string) (string, error) {
cmd := exec.Command(binary, "image", "inspect",
"-f", "{{ .Id }}",
containerNameOrID, // ... against the container
)
lines, err := exec.OutputLines(cmd)
if err != nil {
return "", err
}
if len(lines) != 1 {
return "", errors.Errorf("image ID should only be one line, got %d lines", len(lines))
}
return lines[0], nil
}

// 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
}

func GetDefaultRuntime() (string, error) {
if _, err := osexec.LookPath("docker"); err != nil {
if !syserrors.Is(err, osexec.ErrNotFound) {
return "", err
}

if _, err := osexec.LookPath("podman"); err != nil {
return "", err
}
return "podman", nil
}
return "docker", nil
}
2 changes: 2 additions & 0 deletions pkg/cmd/kind/load/load.go
Original file line number Diff line number Diff line change
Expand Up @@ -25,6 +25,7 @@ import (
"sigs.k8s.io/kind/pkg/cmd"
dockerimage "sigs.k8s.io/kind/pkg/cmd/kind/load/docker-image"
imagearchive "sigs.k8s.io/kind/pkg/cmd/kind/load/image-archive"
imageload "sigs.k8s.io/kind/pkg/cmd/kind/load/image-load"
"sigs.k8s.io/kind/pkg/log"
)

Expand All @@ -46,5 +47,6 @@ func NewCommand(logger log.Logger, streams cmd.IOStreams) *cobra.Command {
// add subcommands
cmd.AddCommand(dockerimage.NewCommand(logger, streams))
cmd.AddCommand(imagearchive.NewCommand(logger, streams))
cmd.AddCommand(imageload.NewCommand(logger, streams))
return cmd
}

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