kaniko/pkg/executor/executor.go

309 lines
8.7 KiB
Go

/*
Copyright 2018 Google LLC
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 executor
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"net/http"
"os"
"path/filepath"
"strconv"
"github.com/docker/docker/builder/dockerfile/instructions"
"github.com/google/go-containerregistry/pkg/authn"
"github.com/google/go-containerregistry/pkg/authn/k8schain"
"github.com/google/go-containerregistry/pkg/name"
"github.com/google/go-containerregistry/pkg/v1"
"github.com/google/go-containerregistry/pkg/v1/empty"
"github.com/google/go-containerregistry/pkg/v1/mutate"
"github.com/google/go-containerregistry/pkg/v1/remote"
"github.com/google/go-containerregistry/pkg/v1/tarball"
"github.com/sirupsen/logrus"
"github.com/GoogleContainerTools/kaniko/pkg/commands"
"github.com/GoogleContainerTools/kaniko/pkg/constants"
"github.com/GoogleContainerTools/kaniko/pkg/dockerfile"
"github.com/GoogleContainerTools/kaniko/pkg/snapshot"
"github.com/GoogleContainerTools/kaniko/pkg/util"
"github.com/GoogleContainerTools/kaniko/pkg/version"
)
// KanikoBuildArgs contains all the args required to build the image
type KanikoBuildArgs struct {
DockerfilePath string
SrcContext string
SnapshotMode string
Args []string
SingleSnapshot bool
Reproducible bool
Target string
}
func DoBuild(k KanikoBuildArgs) (v1.Image, error) {
// Parse dockerfile and unpack base image to root
d, err := ioutil.ReadFile(k.DockerfilePath)
if err != nil {
return nil, err
}
stages, err := dockerfile.Parse(d)
if err != nil {
return nil, err
}
if err := dockerfile.ValidateTarget(stages, k.Target); err != nil {
return nil, err
}
dockerfile.ResolveStages(stages)
hasher, err := getHasher(k.SnapshotMode)
if err != nil {
return nil, err
}
for index, stage := range stages {
finalStage := (index == len(stages)-1) || (k.Target == stage.Name)
// Unpack file system to root
sourceImage, err := util.RetrieveSourceImage(index, k.Args, stages)
if err != nil {
return nil, err
}
if err := util.GetFSFromImage(sourceImage); err != nil {
return nil, err
}
l := snapshot.NewLayeredMap(hasher)
snapshotter := snapshot.NewSnapshotter(l, constants.RootDir)
// Take initial snapshot
if err := snapshotter.Init(); err != nil {
return nil, err
}
imageConfig, err := sourceImage.ConfigFile()
if sourceImage == empty.Image {
imageConfig.Config.Env = constants.ScratchEnvVars
}
if err != nil {
return nil, err
}
if err := resolveOnBuild(&stage, &imageConfig.Config); err != nil {
return nil, err
}
buildArgs := dockerfile.NewBuildArgs(k.Args)
for index, cmd := range stage.Commands {
finalCmd := index == len(stage.Commands)-1
dockerCommand, err := commands.GetCommand(cmd, k.SrcContext)
if err != nil {
return nil, err
}
if dockerCommand == nil {
continue
}
if err := dockerCommand.ExecuteCommand(&imageConfig.Config, buildArgs); err != nil {
return nil, err
}
// Don't snapshot if it's not the final stage and not the final command
// Also don't snapshot if it's the final stage, not the final command, and single snapshot is set
if (!finalStage && !finalCmd) || (finalStage && !finalCmd && k.SingleSnapshot) {
continue
}
// Now, we get the files to snapshot from this command and take the snapshot
snapshotFiles := dockerCommand.FilesToSnapshot()
if finalCmd {
snapshotFiles = nil
}
contents, err := snapshotter.TakeSnapshot(snapshotFiles)
if err != nil {
return nil, err
}
util.MoveVolumeWhitelistToWhitelist()
if contents == nil {
logrus.Info("No files were changed, appending empty layer to config.")
continue
}
// Append the layer to the image
opener := func() (io.ReadCloser, error) {
return ioutil.NopCloser(bytes.NewReader(contents)), nil
}
layer, err := tarball.LayerFromOpener(opener)
if err != nil {
return nil, err
}
sourceImage, err = mutate.Append(sourceImage,
mutate.Addendum{
Layer: layer,
History: v1.History{
Author: constants.Author,
CreatedBy: dockerCommand.CreatedBy(),
},
},
)
if err != nil {
return nil, err
}
}
sourceImage, err = mutate.Config(sourceImage, imageConfig.Config)
if err != nil {
return nil, err
}
if finalStage {
if k.Reproducible {
sourceImage, err = mutate.Canonical(sourceImage)
if err != nil {
return nil, err
}
}
return sourceImage, nil
}
if err := saveStageAsTarball(index, sourceImage); err != nil {
return nil, err
}
if err := saveStageDependencies(index, stages, buildArgs.Clone()); err != nil {
return nil, err
}
// Delete the filesystem
if err := util.DeleteFilesystem(); err != nil {
return nil, err
}
}
return nil, err
}
type withUserAgent struct {
t http.RoundTripper
}
func (w *withUserAgent) RoundTrip(r *http.Request) (*http.Response, error) {
r.Header.Set("User-Agent", fmt.Sprintf("kaniko/%s", version.Version()))
return w.t.RoundTrip(r)
}
func DoPush(image v1.Image, destinations []string, tarPath string) error {
// continue pushing unless an error occurs
for _, destination := range destinations {
// Push the image
destRef, err := name.NewTag(destination, name.WeakValidation)
if err != nil {
return err
}
if tarPath != "" {
return tarball.WriteToFile(tarPath, destRef, image, nil)
}
k8sc, err := k8schain.NewNoClient()
if err != nil {
return err
}
kc := authn.NewMultiKeychain(authn.DefaultKeychain, k8sc)
pushAuth, err := kc.Resolve(destRef.Context().Registry)
if err != nil {
return err
}
// Create a transport to set our user-agent.
rt := &withUserAgent{t: http.DefaultTransport}
if err := remote.Write(destRef, image, pushAuth, rt, remote.WriteOptions{}); err != nil {
logrus.Error(fmt.Errorf("Failed to push to destination %s", destination))
return err
}
}
return nil
}
func saveStageDependencies(index int, stages []instructions.Stage, buildArgs *dockerfile.BuildArgs) error {
// First, get the files in this stage later stages will need
dependencies, err := dockerfile.Dependencies(index, stages, buildArgs)
logrus.Infof("saving dependencies %s", dependencies)
if err != nil {
return err
}
if len(dependencies) == 0 {
return nil
}
// Then, create the directory they will exist in
i := strconv.Itoa(index)
dependencyDir := filepath.Join(constants.KanikoDir, i)
if err := os.MkdirAll(dependencyDir, 0755); err != nil {
return err
}
// Now, copy over dependencies to this dir
for _, d := range dependencies {
fi, err := os.Lstat(d)
if err != nil {
return err
}
dest := filepath.Join(dependencyDir, d)
if fi.IsDir() {
if err := util.CopyDir(d, dest); err != nil {
return err
}
} else if fi.Mode()&os.ModeSymlink != 0 {
if err := util.CopySymlink(d, dest); err != nil {
return err
}
} else {
if err := util.CopyFile(d, dest); err != nil {
return err
}
}
}
return nil
}
func saveStageAsTarball(stageIndex int, image v1.Image) error {
destRef, err := name.NewTag("temp/tag", name.WeakValidation)
if err != nil {
return err
}
if err := os.MkdirAll(constants.KanikoIntermediateStagesDir, 0750); err != nil {
return err
}
tarPath := filepath.Join(constants.KanikoIntermediateStagesDir, strconv.Itoa(stageIndex))
logrus.Infof("Storing source image from stage %d at path %s", stageIndex, tarPath)
return tarball.WriteToFile(tarPath, destRef, image, nil)
}
func getHasher(snapshotMode string) (func(string) (string, error), error) {
if snapshotMode == constants.SnapshotModeTime {
logrus.Info("Only file modification time will be considered when snapshotting")
return util.MtimeHasher(), nil
}
if snapshotMode == constants.SnapshotModeFull {
return util.Hasher(), nil
}
return nil, fmt.Errorf("%s is not a valid snapshot mode", snapshotMode)
}
func resolveOnBuild(stage *instructions.Stage, config *v1.Config) error {
if config.OnBuild == nil {
return nil
}
// Otherwise, parse into commands
cmds, err := dockerfile.ParseCommands(config.OnBuild)
if err != nil {
return err
}
// Append to the beginning of the commands in the stage
stage.Commands = append(cmds, stage.Commands...)
logrus.Infof("Executing %v build triggers", len(cmds))
// Blank out the Onbuild command list for this image
config.OnBuild = nil
return nil
}