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|
package imagebuildah
import (
"bytes"
"context"
"fmt"
"io"
"io/ioutil"
"net/http"
"os"
"os/exec"
"path/filepath"
"strconv"
"strings"
"time"
cp "github.com/containers/image/copy"
is "github.com/containers/image/storage"
"github.com/containers/image/transports"
"github.com/containers/image/transports/alltransports"
"github.com/containers/image/types"
"github.com/containers/storage"
"github.com/containers/storage/pkg/archive"
"github.com/containers/storage/pkg/stringid"
"github.com/docker/docker/builder/dockerfile/parser"
docker "github.com/fsouza/go-dockerclient"
"github.com/opencontainers/image-spec/specs-go/v1"
"github.com/opencontainers/runtime-spec/specs-go"
"github.com/openshift/imagebuilder"
"github.com/pkg/errors"
"github.com/projectatomic/buildah"
"github.com/projectatomic/buildah/util"
"github.com/sirupsen/logrus"
)
const (
PullIfMissing = buildah.PullIfMissing
PullAlways = buildah.PullAlways
PullNever = buildah.PullNever
OCIv1ImageFormat = buildah.OCIv1ImageManifest
Dockerv2ImageFormat = buildah.Dockerv2ImageManifest
Gzip = archive.Gzip
Bzip2 = archive.Bzip2
Xz = archive.Xz
Uncompressed = archive.Uncompressed
)
// Mount is a mountpoint for the build container.
type Mount specs.Mount
// BuildOptions can be used to alter how an image is built.
type BuildOptions struct {
// ContextDirectory is the default source location for COPY and ADD
// commands.
ContextDirectory string
// PullPolicy controls whether or not we pull images. It should be one
// of PullIfMissing, PullAlways, or PullNever.
PullPolicy buildah.PullPolicy
// Registry is a value which is prepended to the image's name, if it
// needs to be pulled and the image name alone can not be resolved to a
// reference to a source image. No separator is implicitly added.
Registry string
// Transport is a value which is prepended to the image's name, if it
// needs to be pulled and the image name alone, or the image name and
// the registry together, can not be resolved to a reference to a
// source image. No separator is implicitly added.
Transport string
// IgnoreUnrecognizedInstructions tells us to just log instructions we
// don't recognize, and try to keep going.
IgnoreUnrecognizedInstructions bool
// Quiet tells us whether or not to announce steps as we go through them.
Quiet bool
// Isolation controls how Run() runs things.
Isolation buildah.Isolation
// Runtime is the name of the command to run for RUN instructions when
// Isolation is either IsolationDefault or IsolationOCI. It should
// accept the same arguments and flags that runc does.
Runtime string
// RuntimeArgs adds global arguments for the runtime.
RuntimeArgs []string
// TransientMounts is a list of mounts that won't be kept in the image.
TransientMounts []Mount
// Compression specifies the type of compression which is applied to
// layer blobs. The default is to not use compression, but
// archive.Gzip is recommended.
Compression archive.Compression
// Arguments which can be interpolated into Dockerfiles
Args map[string]string
// Name of the image to write to.
Output string
// Additional tags to add to the image that we write, if we know of a
// way to add them.
AdditionalTags []string
// Log is a callback that will print a progress message. If no value
// is supplied, the message will be sent to Err (or os.Stderr, if Err
// is nil) by default.
Log func(format string, args ...interface{})
// In is connected to stdin for RUN instructions.
In io.Reader
// Out is a place where non-error log messages are sent.
Out io.Writer
// Err is a place where error log messages should be sent.
Err io.Writer
// SignaturePolicyPath specifies an override location for the signature
// policy which should be used for verifying the new image as it is
// being written. Except in specific circumstances, no value should be
// specified, indicating that the shared, system-wide default policy
// should be used.
SignaturePolicyPath string
// ReportWriter is an io.Writer which will be used to report the
// progress of the (possible) pulling of the source image and the
// writing of the new image.
ReportWriter io.Writer
// OutputFormat is the format of the output image's manifest and
// configuration data.
// Accepted values are OCIv1ImageFormat and Dockerv2ImageFormat.
OutputFormat string
// SystemContext holds parameters used for authentication.
SystemContext *types.SystemContext
// NamespaceOptions controls how we set up namespaces processes that we
// might need when handling RUN instructions.
NamespaceOptions []buildah.NamespaceOption
// ConfigureNetwork controls whether or not network interfaces and
// routing are configured for a new network namespace (i.e., when not
// joining another's namespace and not just using the host's
// namespace), effectively deciding whether or not the process has a
// usable network.
ConfigureNetwork buildah.NetworkConfigurationPolicy
// CNIPluginPath is the location of CNI plugin helpers, if they should be
// run from a location other than the default location.
CNIPluginPath string
// CNIConfigDir is the location of CNI configuration files, if the files in
// the default configuration directory shouldn't be used.
CNIConfigDir string
// ID mapping options to use if we're setting up our own user namespace
// when handling RUN instructions.
IDMappingOptions *buildah.IDMappingOptions
// AddCapabilities is a list of capabilities to add to the default set when
// handling RUN instructions.
AddCapabilities []string
// DropCapabilities is a list of capabilities to remove from the default set
// when handling RUN instructions. If a capability appears in both lists, it
// will be dropped.
DropCapabilities []string
CommonBuildOpts *buildah.CommonBuildOptions
// DefaultMountsFilePath is the file path holding the mounts to be mounted in "host-path:container-path" format
DefaultMountsFilePath string
// IIDFile tells the builder to write the image ID to the specified file
IIDFile string
// Squash tells the builder to produce an image with a single layer
// instead of with possibly more than one layer.
Squash bool
// Labels metadata for an image
Labels []string
// Annotation metadata for an image
Annotations []string
// OnBuild commands to be run by images based on this image
OnBuild []string
// Layers tells the builder to create a cache of images for each step in the Dockerfile
Layers bool
// NoCache tells the builder to build the image from scratch without checking for a cache.
// It creates a new set of cached images for the build.
NoCache bool
// RemoveIntermediateCtrs tells the builder whether to remove intermediate containers used
// during the build process. Default is true.
RemoveIntermediateCtrs bool
// ForceRmIntermediateCtrs tells the builder to remove all intermediate containers even if
// the build was unsuccessful.
ForceRmIntermediateCtrs bool
}
// Executor is a buildah-based implementation of the imagebuilder.Executor
// interface.
type Executor struct {
index int
name string
named map[string]*Executor
store storage.Store
contextDir string
builder *buildah.Builder
pullPolicy buildah.PullPolicy
registry string
transport string
ignoreUnrecognizedInstructions bool
quiet bool
runtime string
runtimeArgs []string
transientMounts []Mount
compression archive.Compression
output string
outputFormat string
additionalTags []string
log func(format string, args ...interface{})
in io.Reader
out io.Writer
err io.Writer
signaturePolicyPath string
systemContext *types.SystemContext
mountPoint string
preserved int
volumes imagebuilder.VolumeSet
volumeCache map[string]string
volumeCacheInfo map[string]os.FileInfo
reportWriter io.Writer
isolation buildah.Isolation
namespaceOptions []buildah.NamespaceOption
configureNetwork buildah.NetworkConfigurationPolicy
cniPluginPath string
cniConfigDir string
idmappingOptions *buildah.IDMappingOptions
commonBuildOptions *buildah.CommonBuildOptions
defaultMountsFilePath string
iidfile string
squash bool
labels []string
annotations []string
onbuild []string
layers bool
topLayers []string
noCache bool
removeIntermediateCtrs bool
forceRmIntermediateCtrs bool
containerIDs []string // Stores the IDs of the successful intermediate containers used during layer build
}
// withName creates a new child executor that will be used whenever a COPY statement uses --from=NAME.
func (b *Executor) withName(name string, index int) *Executor {
if b.named == nil {
b.named = make(map[string]*Executor)
}
copied := *b
copied.index = index
copied.name = name
child := &copied
b.named[name] = child
if idx := strconv.Itoa(index); idx != name {
b.named[idx] = child
}
return child
}
// Preserve informs the executor that from this point on, it needs to ensure
// that only COPY and ADD instructions can modify the contents of this
// directory or anything below it.
// The Executor handles this by caching the contents of directories which have
// been marked this way before executing a RUN instruction, invalidating that
// cache when an ADD or COPY instruction sets any location under the directory
// as the destination, and using the cache to reset the contents of the
// directory tree after processing each RUN instruction.
// It would be simpler if we could just mark the directory as a read-only bind
// mount of itself during Run(), but the directory is expected to be remain
// writeable, even if any changes within it are ultimately discarded.
func (b *Executor) Preserve(path string) error {
logrus.Debugf("PRESERVE %q", path)
if b.volumes.Covers(path) {
// This path is already a subdirectory of a volume path that
// we're already preserving, so there's nothing new to be done
// except ensure that it exists.
archivedPath := filepath.Join(b.mountPoint, path)
if err := os.MkdirAll(archivedPath, 0755); err != nil {
return errors.Wrapf(err, "error ensuring volume path %q exists", archivedPath)
}
if err := b.volumeCacheInvalidate(path); err != nil {
return errors.Wrapf(err, "error ensuring volume path %q is preserved", archivedPath)
}
return nil
}
// Figure out where the cache for this volume would be stored.
b.preserved++
cacheDir, err := b.store.ContainerDirectory(b.builder.ContainerID)
if err != nil {
return errors.Errorf("unable to locate temporary directory for container")
}
cacheFile := filepath.Join(cacheDir, fmt.Sprintf("volume%d.tar", b.preserved))
// Save info about the top level of the location that we'll be archiving.
archivedPath := filepath.Join(b.mountPoint, path)
// Try and resolve the symlink (if one exists)
// Set archivedPath and path based on whether a symlink is found or not
if symLink, err := resolveSymLink(b.mountPoint, path); err == nil {
archivedPath = filepath.Join(b.mountPoint, symLink)
path = symLink
} else {
return errors.Wrapf(err, "error reading symbolic link to %q", path)
}
st, err := os.Stat(archivedPath)
if os.IsNotExist(err) {
if err = os.MkdirAll(archivedPath, 0755); err != nil {
return errors.Wrapf(err, "error ensuring volume path %q exists", archivedPath)
}
st, err = os.Stat(archivedPath)
}
if err != nil {
logrus.Debugf("error reading info about %q: %v", archivedPath, err)
return errors.Wrapf(err, "error reading info about volume path %q", archivedPath)
}
b.volumeCacheInfo[path] = st
if !b.volumes.Add(path) {
// This path is not a subdirectory of a volume path that we're
// already preserving, so adding it to the list should work.
return errors.Errorf("error adding %q to the volume cache", path)
}
b.volumeCache[path] = cacheFile
// Now prune cache files for volumes that are now supplanted by this one.
removed := []string{}
for cachedPath := range b.volumeCache {
// Walk our list of cached volumes, and check that they're
// still in the list of locations that we need to cache.
found := false
for _, volume := range b.volumes {
if volume == cachedPath {
// We need to keep this volume's cache.
found = true
break
}
}
if !found {
// We don't need to keep this volume's cache. Make a
// note to remove it.
removed = append(removed, cachedPath)
}
}
// Actually remove the caches that we decided to remove.
for _, cachedPath := range removed {
archivedPath := filepath.Join(b.mountPoint, cachedPath)
logrus.Debugf("no longer need cache of %q in %q", archivedPath, b.volumeCache[cachedPath])
if err := os.Remove(b.volumeCache[cachedPath]); err != nil {
return errors.Wrapf(err, "error removing %q", b.volumeCache[cachedPath])
}
delete(b.volumeCache, cachedPath)
}
return nil
}
// Remove any volume cache item which will need to be re-saved because we're
// writing to part of it.
func (b *Executor) volumeCacheInvalidate(path string) error {
invalidated := []string{}
for cachedPath := range b.volumeCache {
if strings.HasPrefix(path, cachedPath+string(os.PathSeparator)) {
invalidated = append(invalidated, cachedPath)
}
}
for _, cachedPath := range invalidated {
if err := os.Remove(b.volumeCache[cachedPath]); err != nil {
return errors.Wrapf(err, "error removing volume cache %q", b.volumeCache[cachedPath])
}
archivedPath := filepath.Join(b.mountPoint, cachedPath)
logrus.Debugf("invalidated volume cache for %q from %q", archivedPath, b.volumeCache[cachedPath])
delete(b.volumeCache, cachedPath)
}
return nil
}
// Save the contents of each of the executor's list of volumes for which we
// don't already have a cache file.
func (b *Executor) volumeCacheSave() error {
for cachedPath, cacheFile := range b.volumeCache {
archivedPath := filepath.Join(b.mountPoint, cachedPath)
_, err := os.Stat(cacheFile)
if err == nil {
logrus.Debugf("contents of volume %q are already cached in %q", archivedPath, cacheFile)
continue
}
if !os.IsNotExist(err) {
return errors.Wrapf(err, "error checking for cache of %q in %q", archivedPath, cacheFile)
}
if err := os.MkdirAll(archivedPath, 0755); err != nil {
return errors.Wrapf(err, "error ensuring volume path %q exists", archivedPath)
}
logrus.Debugf("caching contents of volume %q in %q", archivedPath, cacheFile)
cache, err := os.Create(cacheFile)
if err != nil {
return errors.Wrapf(err, "error creating archive at %q", cacheFile)
}
defer cache.Close()
rc, err := archive.Tar(archivedPath, archive.Uncompressed)
if err != nil {
return errors.Wrapf(err, "error archiving %q", archivedPath)
}
defer rc.Close()
_, err = io.Copy(cache, rc)
if err != nil {
return errors.Wrapf(err, "error archiving %q to %q", archivedPath, cacheFile)
}
}
return nil
}
// Restore the contents of each of the executor's list of volumes.
func (b *Executor) volumeCacheRestore() error {
for cachedPath, cacheFile := range b.volumeCache {
archivedPath := filepath.Join(b.mountPoint, cachedPath)
logrus.Debugf("restoring contents of volume %q from %q", archivedPath, cacheFile)
cache, err := os.Open(cacheFile)
if err != nil {
return errors.Wrapf(err, "error opening archive at %q", cacheFile)
}
defer cache.Close()
if err := os.RemoveAll(archivedPath); err != nil {
return errors.Wrapf(err, "error clearing volume path %q", archivedPath)
}
if err := os.MkdirAll(archivedPath, 0755); err != nil {
return errors.Wrapf(err, "error recreating volume path %q", archivedPath)
}
err = archive.Untar(cache, archivedPath, nil)
if err != nil {
return errors.Wrapf(err, "error extracting archive at %q", archivedPath)
}
if st, ok := b.volumeCacheInfo[cachedPath]; ok {
if err := os.Chmod(archivedPath, st.Mode()); err != nil {
return errors.Wrapf(err, "error restoring permissions on %q", archivedPath)
}
if err := os.Chown(archivedPath, 0, 0); err != nil {
return errors.Wrapf(err, "error setting ownership on %q", archivedPath)
}
if err := os.Chtimes(archivedPath, st.ModTime(), st.ModTime()); err != nil {
return errors.Wrapf(err, "error restoring datestamps on %q", archivedPath)
}
}
}
return nil
}
// Copy copies data into the working tree. The "Download" field is how
// imagebuilder tells us the instruction was "ADD" and not "COPY".
func (b *Executor) Copy(excludes []string, copies ...imagebuilder.Copy) error {
for _, copy := range copies {
logrus.Debugf("COPY %#v, %#v", excludes, copy)
if err := b.volumeCacheInvalidate(copy.Dest); err != nil {
return err
}
sources := []string{}
for _, src := range copy.Src {
if strings.HasPrefix(src, "http://") || strings.HasPrefix(src, "https://") {
sources = append(sources, src)
} else if len(copy.From) > 0 {
if other, ok := b.named[copy.From]; ok && other.index < b.index {
sources = append(sources, filepath.Join(other.mountPoint, src))
} else {
return errors.Errorf("the stage %q has not been built", copy.From)
}
} else {
sources = append(sources, filepath.Join(b.contextDir, src))
}
}
if err := b.builder.Add(copy.Dest, copy.Download, buildah.AddAndCopyOptions{}, sources...); err != nil {
return err
}
}
return nil
}
func convertMounts(mounts []Mount) []specs.Mount {
specmounts := []specs.Mount{}
for _, m := range mounts {
s := specs.Mount{
Destination: m.Destination,
Type: m.Type,
Source: m.Source,
Options: m.Options,
}
specmounts = append(specmounts, s)
}
return specmounts
}
// Run executes a RUN instruction using the working container as a root
// directory.
func (b *Executor) Run(run imagebuilder.Run, config docker.Config) error {
logrus.Debugf("RUN %#v, %#v", run, config)
if b.builder == nil {
return errors.Errorf("no build container available")
}
stdin := b.in
if stdin == nil {
devNull, err := os.Open(os.DevNull)
if err != nil {
return errors.Errorf("error opening %q for reading: %v", os.DevNull, err)
}
defer devNull.Close()
stdin = devNull
}
options := buildah.RunOptions{
Hostname: config.Hostname,
Runtime: b.runtime,
Args: b.runtimeArgs,
Mounts: convertMounts(b.transientMounts),
Env: config.Env,
User: config.User,
WorkingDir: config.WorkingDir,
Entrypoint: config.Entrypoint,
Cmd: config.Cmd,
Stdin: stdin,
Stdout: b.out,
Stderr: b.err,
Quiet: b.quiet,
}
if config.NetworkDisabled {
options.ConfigureNetwork = buildah.NetworkDisabled
} else {
options.ConfigureNetwork = buildah.NetworkEnabled
}
args := run.Args
if run.Shell {
args = append([]string{"/bin/sh", "-c"}, args...)
}
if err := b.volumeCacheSave(); err != nil {
return err
}
err := b.builder.Run(args, options)
if err2 := b.volumeCacheRestore(); err2 != nil {
if err == nil {
return err2
}
}
return err
}
// UnrecognizedInstruction is called when we encounter an instruction that the
// imagebuilder parser didn't understand.
func (b *Executor) UnrecognizedInstruction(step *imagebuilder.Step) error {
errStr := fmt.Sprintf("Build error: Unknown instruction: %q ", step.Command)
err := fmt.Sprintf(errStr+"%#v", step)
if b.ignoreUnrecognizedInstructions {
logrus.Debugf(err)
return nil
}
switch logrus.GetLevel() {
case logrus.ErrorLevel:
logrus.Errorf(errStr)
case logrus.DebugLevel:
logrus.Debugf(err)
default:
logrus.Errorf("+(UNHANDLED LOGLEVEL) %#v", step)
}
return errors.Errorf(err)
}
// NewExecutor creates a new instance of the imagebuilder.Executor interface.
func NewExecutor(store storage.Store, options BuildOptions) (*Executor, error) {
exec := Executor{
store: store,
contextDir: options.ContextDirectory,
pullPolicy: options.PullPolicy,
registry: options.Registry,
transport: options.Transport,
ignoreUnrecognizedInstructions: options.IgnoreUnrecognizedInstructions,
quiet: options.Quiet,
runtime: options.Runtime,
runtimeArgs: options.RuntimeArgs,
transientMounts: options.TransientMounts,
compression: options.Compression,
output: options.Output,
outputFormat: options.OutputFormat,
additionalTags: options.AdditionalTags,
signaturePolicyPath: options.SignaturePolicyPath,
systemContext: options.SystemContext,
volumeCache: make(map[string]string),
volumeCacheInfo: make(map[string]os.FileInfo),
log: options.Log,
in: options.In,
out: options.Out,
err: options.Err,
reportWriter: options.ReportWriter,
isolation: options.Isolation,
namespaceOptions: options.NamespaceOptions,
configureNetwork: options.ConfigureNetwork,
cniPluginPath: options.CNIPluginPath,
cniConfigDir: options.CNIConfigDir,
idmappingOptions: options.IDMappingOptions,
commonBuildOptions: options.CommonBuildOpts,
defaultMountsFilePath: options.DefaultMountsFilePath,
iidfile: options.IIDFile,
squash: options.Squash,
labels: append([]string{}, options.Labels...),
annotations: append([]string{}, options.Annotations...),
layers: options.Layers,
noCache: options.NoCache,
removeIntermediateCtrs: options.RemoveIntermediateCtrs,
forceRmIntermediateCtrs: options.ForceRmIntermediateCtrs,
}
if exec.err == nil {
exec.err = os.Stderr
}
if exec.out == nil {
exec.out = os.Stdout
}
if exec.log == nil {
stepCounter := 0
exec.log = func(format string, args ...interface{}) {
stepCounter++
prefix := fmt.Sprintf("STEP %d: ", stepCounter)
suffix := "\n"
fmt.Fprintf(exec.err, prefix+format+suffix, args...)
}
}
return &exec, nil
}
// Prepare creates a working container based on specified image, or if one
// isn't specified, the first FROM instruction we can find in the parsed tree.
func (b *Executor) Prepare(ctx context.Context, ib *imagebuilder.Builder, node *parser.Node, from string) error {
if from == "" {
base, err := ib.From(node)
if err != nil {
logrus.Debugf("Prepare(node.Children=%#v)", node.Children)
return errors.Wrapf(err, "error determining starting point for build")
}
from = base
}
logrus.Debugf("FROM %#v", from)
if !b.quiet {
b.log("FROM %s", from)
}
builderOptions := buildah.BuilderOptions{
Args: ib.Args,
FromImage: from,
PullPolicy: b.pullPolicy,
Registry: b.registry,
Transport: b.transport,
SignaturePolicyPath: b.signaturePolicyPath,
ReportWriter: b.reportWriter,
SystemContext: b.systemContext,
Isolation: b.isolation,
NamespaceOptions: b.namespaceOptions,
ConfigureNetwork: b.configureNetwork,
CNIPluginPath: b.cniPluginPath,
CNIConfigDir: b.cniConfigDir,
IDMappingOptions: b.idmappingOptions,
CommonBuildOpts: b.commonBuildOptions,
DefaultMountsFilePath: b.defaultMountsFilePath,
}
builder, err := buildah.NewBuilder(ctx, b.store, builderOptions)
if err != nil {
return errors.Wrapf(err, "error creating build container")
}
volumes := map[string]struct{}{}
for _, v := range builder.Volumes() {
volumes[v] = struct{}{}
}
dConfig := docker.Config{
Hostname: builder.Hostname(),
Domainname: builder.Domainname(),
User: builder.User(),
Env: builder.Env(),
Cmd: builder.Cmd(),
Image: from,
Volumes: volumes,
WorkingDir: builder.WorkDir(),
Entrypoint: builder.Entrypoint(),
Labels: builder.Labels(),
Shell: builder.Shell(),
StopSignal: builder.StopSignal(),
OnBuild: builder.OnBuild(),
}
var rootfs *docker.RootFS
if builder.Docker.RootFS != nil {
rootfs = &docker.RootFS{
Type: builder.Docker.RootFS.Type,
}
for _, id := range builder.Docker.RootFS.DiffIDs {
rootfs.Layers = append(rootfs.Layers, id.String())
}
}
dImage := docker.Image{
Parent: builder.FromImage,
ContainerConfig: dConfig,
Container: builder.Container,
Author: builder.Maintainer(),
Architecture: builder.Architecture(),
RootFS: rootfs,
}
dImage.Config = &dImage.ContainerConfig
err = ib.FromImage(&dImage, node)
if err != nil {
if err2 := builder.Delete(); err2 != nil {
logrus.Debugf("error deleting container which we failed to update: %v", err2)
}
return errors.Wrapf(err, "error updating build context")
}
mountPoint, err := builder.Mount(builder.MountLabel)
if err != nil {
if err2 := builder.Delete(); err2 != nil {
logrus.Debugf("error deleting container which we failed to mount: %v", err2)
}
return errors.Wrapf(err, "error mounting new container")
}
b.mountPoint = mountPoint
b.builder = builder
// Add the top layer of this image to b.topLayers so we can keep track of them
// when building with cached images.
b.topLayers = append(b.topLayers, builder.TopLayer)
logrus.Debugln("Container ID:", builder.ContainerID)
return nil
}
// Delete deletes the working container, if we have one. The Executor object
// should not be used to build another image, as the name of the output image
// isn't resettable.
func (b *Executor) Delete() (err error) {
if b.builder != nil {
err = b.builder.Delete()
b.builder = nil
}
return err
}
// resolveNameToImageRef creates a types.ImageReference from b.output
func (b *Executor) resolveNameToImageRef() (types.ImageReference, error) {
var (
imageRef types.ImageReference
err error
)
if b.output != "" {
imageRef, err = alltransports.ParseImageName(b.output)
if err != nil {
candidates := util.ResolveName(b.output, "", b.systemContext, b.store)
if len(candidates) == 0 {
return nil, errors.Errorf("error parsing target image name %q", b.output)
}
imageRef2, err2 := is.Transport.ParseStoreReference(b.store, candidates[0])
if err2 != nil {
return nil, errors.Wrapf(err, "error parsing target image name %q", b.output)
}
return imageRef2, nil
}
return imageRef, nil
}
imageRef, err = is.Transport.ParseStoreReference(b.store, "@"+stringid.GenerateRandomID())
if err != nil {
return nil, errors.Wrapf(err, "error parsing reference for image to be written")
}
return imageRef, nil
}
// Execute runs each of the steps in the parsed tree, in turn.
func (b *Executor) Execute(ctx context.Context, ib *imagebuilder.Builder, node *parser.Node) error {
checkForLayers := true
children := node.Children
commitName := b.output
for i, node := range node.Children {
step := ib.Step()
if err := step.Resolve(node); err != nil {
return errors.Wrapf(err, "error resolving step %+v", *node)
}
logrus.Debugf("Parsed Step: %+v", *step)
if !b.quiet {
b.log("%s", step.Original)
}
requiresStart := false
if i < len(node.Children)-1 {
requiresStart = ib.RequiresStart(&parser.Node{Children: node.Children[i+1:]})
}
if !b.layers && !b.noCache {
err := ib.Run(step, b, requiresStart)
if err != nil {
return errors.Wrapf(err, "error building at step %+v", *step)
}
continue
}
if i < len(children)-1 {
b.output = ""
} else {
b.output = commitName
}
var (
cacheID string
err error
imgID string
)
// checkForLayers will be true if b.layers is true and a cached intermediate image is found.
// checkForLayers is set to false when either there is no cached image or a break occurs where
// the instructions in the Dockerfile change from a previous build.
// Don't check for cache if b.noCache is set to true.
if checkForLayers && !b.noCache {
cacheID, err = b.layerExists(ctx, node, children[:i])
if err != nil {
return errors.Wrap(err, "error checking if cached image exists from a previous build")
}
}
if cacheID != "" {
fmt.Fprintf(b.out, "--> Using cache %s\n", cacheID)
}
// If a cache is found for the last step, that means nothing in the
// Dockerfile changed. Just create a copy of the existing image and
// save it with the new name passed in by the user.
if cacheID != "" && i == len(children)-1 {
if err := b.copyExistingImage(ctx, cacheID); err != nil {
return err
}
break
}
if cacheID == "" || !checkForLayers {
checkForLayers = false
err := ib.Run(step, b, requiresStart)
if err != nil {
return errors.Wrapf(err, "error building at step %+v", *step)
}
}
// Commit if no cache is found
if cacheID == "" {
imgID, err = b.Commit(ctx, ib, getCreatedBy(node))
if err != nil {
return errors.Wrapf(err, "error committing container for step %+v", *step)
}
if i == len(children)-1 {
b.log("COMMIT %s", b.output)
}
} else {
// Cache is found, assign imgID the id of the cached image so
// it is used to create the container for the next step.
imgID = cacheID
}
// Add container ID of successful intermediate container to b.containerIDs
b.containerIDs = append(b.containerIDs, b.builder.ContainerID)
// Prepare for the next step with imgID as the new base image.
if i != len(children)-1 {
if err := b.Prepare(ctx, ib, node, imgID); err != nil {
return errors.Wrap(err, "error preparing container for next step")
}
}
}
return nil
}
// copyExistingImage creates a copy of an image already in store
func (b *Executor) copyExistingImage(ctx context.Context, cacheID string) error {
// Get the destination Image Reference
dest, err := b.resolveNameToImageRef()
if err != nil {
return err
}
policyContext, err := util.GetPolicyContext(b.systemContext)
if err != nil {
return err
}
defer policyContext.Destroy()
// Look up the source image, expecting it to be in local storage
src, err := is.Transport.ParseStoreReference(b.store, cacheID)
if err != nil {
return errors.Wrapf(err, "error getting source imageReference for %q", cacheID)
}
if err := cp.Image(ctx, policyContext, dest, src, nil); err != nil {
return errors.Wrapf(err, "error copying image %q", cacheID)
}
b.log("COMMIT %s", b.output)
return nil
}
// layerExists returns true if an intermediate image of currNode exists in the image store from a previous build.
// It verifies tihis by checking the parent of the top layer of the image and the history.
func (b *Executor) layerExists(ctx context.Context, currNode *parser.Node, children []*parser.Node) (string, error) {
// Get the list of images available in the image store
images, err := b.store.Images()
if err != nil {
return "", errors.Wrap(err, "error getting image list from store")
}
for _, image := range images {
layer, err := b.store.Layer(image.TopLayer)
if err != nil {
return "", errors.Wrapf(err, "error getting top layer info")
}
// If the parent of the top layer of an image is equal to the last entry in b.topLayers
// it means that this image is potentially a cached intermediate image from a previous
// build. Next we double check that the history of this image is equivalent to the previous
// lines in the Dockerfile up till the point we are at in the build.
if layer.Parent == b.topLayers[len(b.topLayers)-1] {
history, err := b.getImageHistory(ctx, image.ID)
if err != nil {
return "", errors.Wrapf(err, "error getting history of %q", image.ID)
}
// children + currNode is the point of the Dockerfile we are currently at.
if historyMatches(append(children, currNode), history) {
// This checks if the files copied during build have been changed if the node is
// a COPY or ADD command.
filesMatch, err := b.copiedFilesMatch(currNode, history[len(history)-1].Created)
if err != nil {
return "", errors.Wrapf(err, "error checking if copied files match")
}
if filesMatch {
return image.ID, nil
}
}
}
}
return "", nil
}
// getImageHistory returns the history of imageID.
func (b *Executor) getImageHistory(ctx context.Context, imageID string) ([]v1.History, error) {
imageRef, err := is.Transport.ParseStoreReference(b.store, "@"+imageID)
if err != nil {
return nil, errors.Wrapf(err, "error getting image reference %q", imageID)
}
ref, err := imageRef.NewImage(ctx, nil)
if err != nil {
return nil, errors.Wrap(err, "error creating new image from reference")
}
oci, err := ref.OCIConfig(ctx)
if err != nil {
return nil, errors.Wrapf(err, "error getting oci config of image %q", imageID)
}
return oci.History, nil
}
// getCreatedBy returns the command the image at node will be created by.
func getCreatedBy(node *parser.Node) string {
if node.Value == "run" {
return "/bin/sh -c " + node.Original[4:]
}
return "/bin/sh -c #(nop) " + node.Original
}
// historyMatches returns true if the history of the image matches the lines
// in the Dockerfile till the point of build we are at.
// Used to verify whether a cache of the intermediate image exists and whether
// to run the build again.
func historyMatches(children []*parser.Node, history []v1.History) bool {
i := len(history) - 1
for j := len(children) - 1; j >= 0; j-- {
instruction := children[j].Original
if children[j].Value == "run" {
instruction = instruction[4:]
}
if !strings.Contains(history[i].CreatedBy, instruction) {
return false
}
i--
}
return true
}
// getFilesToCopy goes through node to get all the src files that are copied, added or downloaded.
// It is possible for the Dockerfile to have src as hom*, which means all files that have hom as a prefix.
// Another format is hom?.txt, which means all files that have that name format with the ? replaced by another character.
func (b *Executor) getFilesToCopy(node *parser.Node) ([]string, error) {
currNode := node.Next
var src []string
for currNode.Next != nil {
if currNode.Next == nil {
break
}
if strings.HasPrefix(currNode.Value, "http://") || strings.HasPrefix(currNode.Value, "https://") {
src = append(src, currNode.Value)
continue
}
matches, err := filepath.Glob(filepath.Join(b.contextDir, currNode.Value))
if err != nil {
return nil, errors.Wrapf(err, "error finding match for pattern %q", currNode.Value)
}
src = append(src, matches...)
currNode = currNode.Next
}
return src, nil
}
// copiedFilesMatch checks to see if the node instruction is a COPY or ADD.
// If it is either of those two it checks the timestamps on all the files copied/added
// by the dockerfile. If the host version has a time stamp greater than the time stamp
// of the build, the build will not use the cached version and will rebuild.
func (b *Executor) copiedFilesMatch(node *parser.Node, historyTime *time.Time) (bool, error) {
if node.Value != "add" && node.Value != "copy" {
return true, nil
}
src, err := b.getFilesToCopy(node)
if err != nil {
return false, err
}
for _, item := range src {
// for urls, check the Last-Modified field in the header.
if strings.HasPrefix(item, "http://") || strings.HasPrefix(item, "https://") {
urlContentNew, err := urlContentModified(item, historyTime)
if err != nil {
return false, err
}
if urlContentNew {
return false, nil
}
continue
}
// For local files, walk the file tree and check the time stamps.
timeIsGreater := false
err := filepath.Walk(item, func(path string, info os.FileInfo, err error) error {
if info.ModTime().After(*historyTime) {
timeIsGreater = true
return nil
}
return nil
})
if err != nil {
return false, errors.Wrapf(err, "error walking file tree %q", item)
}
if timeIsGreater {
return false, nil
}
}
return true, nil
}
// urlContentModified sends a get request to the url and checks if the header has a value in
// Last-Modified, and if it does compares the time stamp to that of the history of the cached image.
// returns true if there is no Last-Modified value in the header.
func urlContentModified(url string, historyTime *time.Time) (bool, error) {
resp, err := http.Get(url)
if err != nil {
return false, errors.Wrapf(err, "error getting %q", url)
}
if lastModified := resp.Header.Get("Last-Modified"); lastModified != "" {
lastModifiedTime, err := time.Parse(time.RFC1123, lastModified)
if err != nil {
return false, errors.Wrapf(err, "error parsing time for %q", url)
}
return lastModifiedTime.After(*historyTime), nil
}
logrus.Debugf("Response header did not have Last-Modified %q, will rebuild.", url)
return true, nil
}
// Commit writes the container's contents to an image, using a passed-in tag as
// the name if there is one, generating a unique ID-based one otherwise.
func (b *Executor) Commit(ctx context.Context, ib *imagebuilder.Builder, createdBy string) (string, error) {
imageRef, err := b.resolveNameToImageRef()
if err != nil {
return "", err
}
if ib.Author != "" {
b.builder.SetMaintainer(ib.Author)
}
config := ib.Config()
b.builder.SetCreatedBy(createdBy)
b.builder.SetHostname(config.Hostname)
b.builder.SetDomainname(config.Domainname)
b.builder.SetUser(config.User)
b.builder.ClearPorts()
for p := range config.ExposedPorts {
b.builder.SetPort(string(p))
}
for _, envSpec := range config.Env {
spec := strings.SplitN(envSpec, "=", 2)
b.builder.SetEnv(spec[0], spec[1])
}
b.builder.SetCmd(config.Cmd)
b.builder.ClearVolumes()
for v := range config.Volumes {
b.builder.AddVolume(v)
}
b.builder.ClearOnBuild()
for _, onBuildSpec := range config.OnBuild {
b.builder.SetOnBuild(onBuildSpec)
}
b.builder.SetWorkDir(config.WorkingDir)
b.builder.SetEntrypoint(config.Entrypoint)
b.builder.SetShell(config.Shell)
b.builder.SetStopSignal(config.StopSignal)
b.builder.ClearLabels()
for k, v := range config.Labels {
b.builder.SetLabel(k, v)
}
for _, labelSpec := range b.labels {
label := strings.SplitN(labelSpec, "=", 2)
if len(label) > 1 {
b.builder.SetLabel(label[0], label[1])
} else {
b.builder.SetLabel(label[0], "")
}
}
for _, annotationSpec := range b.annotations {
annotation := strings.SplitN(annotationSpec, "=", 2)
if len(annotation) > 1 {
b.builder.SetAnnotation(annotation[0], annotation[1])
} else {
b.builder.SetAnnotation(annotation[0], "")
}
}
if imageRef != nil {
logName := transports.ImageName(imageRef)
logrus.Debugf("COMMIT %q", logName)
if !b.quiet && !b.layers && !b.noCache {
b.log("COMMIT %s", logName)
}
} else {
logrus.Debugf("COMMIT")
if !b.quiet && !b.layers && !b.noCache {
b.log("COMMIT")
}
}
writer := b.reportWriter
if b.layers || b.noCache {
writer = nil
}
options := buildah.CommitOptions{
Compression: b.compression,
SignaturePolicyPath: b.signaturePolicyPath,
AdditionalTags: b.additionalTags,
ReportWriter: writer,
PreferredManifestType: b.outputFormat,
IIDFile: b.iidfile,
Squash: b.squash,
Parent: b.builder.FromImageID,
}
imgID, err := b.builder.Commit(ctx, imageRef, options)
if err != nil {
return "", err
}
if options.IIDFile == "" && imgID != "" {
fmt.Fprintf(b.out, "--> %s\n", imgID)
}
return imgID, nil
}
// Build takes care of the details of running Prepare/Execute/Commit/Delete
// over each of the one or more parsed Dockerfiles and stages.
func (b *Executor) Build(ctx context.Context, stages imagebuilder.Stages) error {
if len(stages) == 0 {
errors.New("error building: no stages to build")
}
var (
stageExecutor *Executor
lastErr error
)
for _, stage := range stages {
stageExecutor = b.withName(stage.Name, stage.Position)
if err := stageExecutor.Prepare(ctx, stage.Builder, stage.Node, ""); err != nil {
lastErr = err
}
// Always remove the intermediate/build containers, even if the build was unsuccessful.
// If building with layers, remove all intermediate/build containers if b.forceRmIntermediateCtrs
// is true.
if b.forceRmIntermediateCtrs || (!b.layers && !b.noCache) {
defer stageExecutor.Delete()
}
if err := stageExecutor.Execute(ctx, stage.Builder, stage.Node); err != nil {
lastErr = err
}
// Delete the successful intermediate containers if an error in the build
// process occurs and b.removeIntermediateCtrs is true.
if lastErr != nil {
if b.removeIntermediateCtrs {
stageExecutor.deleteSuccessfulIntermediateCtrs()
}
return lastErr
}
b.containerIDs = append(b.containerIDs, stageExecutor.containerIDs...)
}
if !b.layers && !b.noCache {
_, err := stageExecutor.Commit(ctx, stages[len(stages)-1].Builder, "")
if err != nil {
return err
}
}
// If building with layers and b.removeIntermediateCtrs is true
// only remove intermediate container for each step if an error
// during the build process doesn't occur.
// If the build is unsuccessful, the container created at the step
// the failure happened will persist in the container store.
// This if condition will be false if not building with layers and
// the removal of intermediate/build containers will be handled by the
// defer statement above.
if b.removeIntermediateCtrs && (b.layers || b.noCache) {
if err := b.deleteSuccessfulIntermediateCtrs(); err != nil {
return errors.Errorf("Failed to cleanup intermediate containers")
}
}
return nil
}
// BuildDockerfiles parses a set of one or more Dockerfiles (which may be
// URLs), creates a new Executor, and then runs Prepare/Execute/Commit/Delete
// over the entire set of instructions.
func BuildDockerfiles(ctx context.Context, store storage.Store, options BuildOptions, paths ...string) error {
if len(paths) == 0 {
return errors.Errorf("error building: no dockerfiles specified")
}
var dockerfiles []io.ReadCloser
defer func(dockerfiles ...io.ReadCloser) {
for _, d := range dockerfiles {
d.Close()
}
}(dockerfiles...)
for _, dfile := range paths {
var data io.ReadCloser
if strings.HasPrefix(dfile, "http://") || strings.HasPrefix(dfile, "https://") {
logrus.Debugf("reading remote Dockerfile %q", dfile)
resp, err := http.Get(dfile)
if err != nil {
return errors.Wrapf(err, "error getting %q", dfile)
}
if resp.ContentLength == 0 {
resp.Body.Close()
return errors.Errorf("no contents in %q", dfile)
}
data = resp.Body
} else {
// If the Dockerfile isn't found try prepending the
// context directory to it.
if _, err := os.Stat(dfile); os.IsNotExist(err) {
dfile = filepath.Join(options.ContextDirectory, dfile)
}
logrus.Debugf("reading local Dockerfile %q", dfile)
contents, err := os.Open(dfile)
if err != nil {
return errors.Wrapf(err, "error reading %q", dfile)
}
dinfo, err := contents.Stat()
if err != nil {
contents.Close()
return errors.Wrapf(err, "error reading info about %q", dfile)
}
if dinfo.Mode().IsRegular() && dinfo.Size() == 0 {
contents.Close()
return errors.Wrapf(err, "no contents in %q", dfile)
}
data = contents
}
// pre-process Dockerfiles with ".in" suffix
if strings.HasSuffix(dfile, ".in") {
pData, err := preprocessDockerfileContents(data, options.ContextDirectory)
if err != nil {
return err
}
data = *pData
}
dockerfiles = append(dockerfiles, data)
}
mainNode, err := imagebuilder.ParseDockerfile(dockerfiles[0])
if err != nil {
return errors.Wrapf(err, "error parsing main Dockerfile")
}
for _, d := range dockerfiles[1:] {
additionalNode, err := imagebuilder.ParseDockerfile(d)
if err != nil {
return errors.Wrapf(err, "error parsing additional Dockerfile")
}
mainNode.Children = append(mainNode.Children, additionalNode.Children...)
}
exec, err := NewExecutor(store, options)
if err != nil {
return errors.Wrapf(err, "error creating build executor")
}
b := imagebuilder.NewBuilder(options.Args)
stages := imagebuilder.NewStages(mainNode, b)
return exec.Build(ctx, stages)
}
// deleteSuccessfulIntermediateCtrs goes through the container IDs in b.containerIDs
// and deletes the containers associated with that ID.
func (b *Executor) deleteSuccessfulIntermediateCtrs() error {
var lastErr error
for _, ctr := range b.containerIDs {
if err := b.store.DeleteContainer(ctr); err != nil {
logrus.Errorf("error deleting build container %q: %v\n", ctr, err)
lastErr = err
}
}
return lastErr
}
// preprocessDockerfileContents runs CPP(1) in preprocess-only mode on the input
// dockerfile content and will use ctxDir as the base include path.
//
// Note: we cannot use cmd.StdoutPipe() as cmd.Wait() closes it.
func preprocessDockerfileContents(r io.ReadCloser, ctxDir string) (rdrCloser *io.ReadCloser, err error) {
cppPath := "/usr/bin/cpp"
if _, err = os.Stat(cppPath); err != nil {
if os.IsNotExist(err) {
err = errors.Errorf("error: Dockerfile.in support requires %s to be installed", cppPath)
}
return nil, err
}
stdout := bytes.Buffer{}
stderr := bytes.Buffer{}
cmd := exec.Command(cppPath, "-E", "-iquote", ctxDir, "-")
cmd.Stdout = &stdout
cmd.Stderr = &stderr
pipe, err := cmd.StdinPipe()
if err != nil {
return nil, err
}
defer func() {
if err != nil {
pipe.Close()
}
}()
if err = cmd.Start(); err != nil {
return nil, err
}
if _, err = io.Copy(pipe, r); err != nil {
return nil, err
}
pipe.Close()
if err = cmd.Wait(); err != nil {
if stderr.Len() > 0 {
err = fmt.Errorf("%v: %s", err, strings.TrimSpace(stderr.String()))
}
return nil, errors.Wrapf(err, "error pre-processing Dockerfile")
}
rc := ioutil.NopCloser(bytes.NewReader(stdout.Bytes()))
return &rc, nil
}
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