builder/dockerfile/builder.go
package dockerfile // import "github.com/docker/docker/builder/dockerfile"
import (
"bytes"
"context"
"fmt"
"io"
"sort"
"strings"
"github.com/containerd/log"
"github.com/containerd/platforms"
"github.com/docker/docker/api/types"
"github.com/docker/docker/api/types/backend"
"github.com/docker/docker/api/types/container"
"github.com/docker/docker/builder"
"github.com/docker/docker/builder/remotecontext"
"github.com/docker/docker/errdefs"
"github.com/docker/docker/pkg/idtools"
"github.com/docker/docker/pkg/streamformatter"
"github.com/docker/docker/pkg/stringid"
"github.com/moby/buildkit/frontend/dockerfile/instructions"
"github.com/moby/buildkit/frontend/dockerfile/parser"
"github.com/moby/buildkit/frontend/dockerfile/shell"
ocispec "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/pkg/errors"
"golang.org/x/sync/syncmap"
)
var validCommitCommands = map[string]bool{
"cmd": true,
"entrypoint": true,
"healthcheck": true,
"env": true,
"expose": true,
"label": true,
"onbuild": true,
"stopsignal": true,
"user": true,
"volume": true,
"workdir": true,
}
const (
stepFormat = "Step %d/%d : %v"
)
// BuildManager is shared across all Builder objects
type BuildManager struct {
idMapping idtools.IdentityMapping
backend builder.Backend
pathCache pathCache // TODO: make this persistent
}
// NewBuildManager creates a BuildManager
func NewBuildManager(b builder.Backend, identityMapping idtools.IdentityMapping) (*BuildManager, error) {
bm := &BuildManager{
backend: b,
pathCache: &syncmap.Map{},
idMapping: identityMapping,
}
return bm, nil
}
// Build starts a new build from a BuildConfig
func (bm *BuildManager) Build(ctx context.Context, config backend.BuildConfig) (*builder.Result, error) {
buildsTriggered.Inc()
if config.Options.Dockerfile == "" {
config.Options.Dockerfile = builder.DefaultDockerfileName
}
source, dockerfile, err := remotecontext.Detect(config)
if err != nil {
return nil, err
}
defer func() {
if source != nil {
if err := source.Close(); err != nil {
log.G(ctx).Debugf("[BUILDER] failed to remove temporary context: %v", err)
}
}
}()
ctx, cancel := context.WithCancel(ctx)
defer cancel()
builderOptions := builderOptions{
Options: config.Options,
ProgressWriter: config.ProgressWriter,
Backend: bm.backend,
PathCache: bm.pathCache,
IDMapping: bm.idMapping,
}
b, err := newBuilder(ctx, builderOptions)
if err != nil {
return nil, err
}
return b.build(ctx, source, dockerfile)
}
// builderOptions are the dependencies required by the builder
type builderOptions struct {
Options *types.ImageBuildOptions
Backend builder.Backend
ProgressWriter backend.ProgressWriter
PathCache pathCache
IDMapping idtools.IdentityMapping
}
// Builder is a Dockerfile builder
// It implements the builder.Backend interface.
type Builder struct {
options *types.ImageBuildOptions
Stdout io.Writer
Stderr io.Writer
Aux *streamformatter.AuxFormatter
Output io.Writer
docker builder.Backend
idMapping idtools.IdentityMapping
disableCommit bool
imageSources *imageSources
pathCache pathCache
containerManager *containerManager
imageProber ImageProber
platform *ocispec.Platform
}
// newBuilder creates a new Dockerfile builder from an optional dockerfile and a Options.
func newBuilder(ctx context.Context, options builderOptions) (*Builder, error) {
config := options.Options
if config == nil {
config = new(types.ImageBuildOptions)
}
imageProber, err := newImageProber(ctx, options.Backend, config.CacheFrom, config.NoCache)
if err != nil {
return nil, err
}
b := &Builder{
options: config,
Stdout: options.ProgressWriter.StdoutFormatter,
Stderr: options.ProgressWriter.StderrFormatter,
Aux: options.ProgressWriter.AuxFormatter,
Output: options.ProgressWriter.Output,
docker: options.Backend,
idMapping: options.IDMapping,
imageSources: newImageSources(options),
pathCache: options.PathCache,
imageProber: imageProber,
containerManager: newContainerManager(options.Backend),
}
// same as in Builder.Build in builder/builder-next/builder.go
// TODO: remove once config.Platform is of type specs.Platform
if config.Platform != "" {
sp, err := platforms.Parse(config.Platform)
if err != nil {
return nil, errdefs.InvalidParameter(err)
}
b.platform = &sp
}
return b, nil
}
// Build 'LABEL' command(s) from '--label' options and add to the last stage
func buildLabelOptions(labels map[string]string, stages []instructions.Stage) {
keys := []string{}
for key := range labels {
keys = append(keys, key)
}
// Sort the label to have a repeatable order
sort.Strings(keys)
for _, key := range keys {
value := labels[key]
stages[len(stages)-1].AddCommand(instructions.NewLabelCommand(key, value, true))
}
}
// Build runs the Dockerfile builder by parsing the Dockerfile and executing
// the instructions from the file.
func (b *Builder) build(ctx context.Context, source builder.Source, dockerfile *parser.Result) (*builder.Result, error) {
defer b.imageSources.Unmount()
stages, metaArgs, err := instructions.Parse(dockerfile.AST, nil)
if err != nil {
var uiErr *instructions.UnknownInstructionError
if errors.As(err, &uiErr) {
buildsFailed.WithValues(metricsUnknownInstructionError).Inc()
}
return nil, errdefs.InvalidParameter(err)
}
if b.options.Target != "" {
targetIx, found := instructions.HasStage(stages, b.options.Target)
if !found {
buildsFailed.WithValues(metricsBuildTargetNotReachableError).Inc()
return nil, errdefs.InvalidParameter(errors.Errorf("target stage %q could not be found", b.options.Target))
}
stages = stages[:targetIx+1]
}
// Add 'LABEL' command specified by '--label' option to the last stage
buildLabelOptions(b.options.Labels, stages)
dockerfile.PrintWarnings(b.Stderr)
dispatchState, err := b.dispatchDockerfileWithCancellation(ctx, stages, metaArgs, dockerfile.EscapeToken, source)
if err != nil {
return nil, err
}
if dispatchState.imageID == "" {
buildsFailed.WithValues(metricsDockerfileEmptyError).Inc()
return nil, errors.New("No image was generated. Is your Dockerfile empty?")
}
return &builder.Result{ImageID: dispatchState.imageID, FromImage: dispatchState.baseImage}, nil
}
func emitImageID(aux *streamformatter.AuxFormatter, state *dispatchState) error {
if aux == nil || state.imageID == "" {
return nil
}
return aux.Emit("", types.BuildResult{ID: state.imageID})
}
func processMetaArg(meta instructions.ArgCommand, shlex *shell.Lex, args *BuildArgs) error {
// shell.Lex currently only support the concatenated string format
envs := shell.EnvsFromSlice(convertMapToEnvList(args.GetAllAllowed()))
if err := meta.Expand(func(word string) (string, error) {
newword, _, err := shlex.ProcessWord(word, envs)
return newword, err
}); err != nil {
return err
}
for _, arg := range meta.Args {
args.AddArg(arg.Key, arg.Value)
args.AddMetaArg(arg.Key, arg.Value)
}
return nil
}
func printCommand(out io.Writer, currentCommandIndex int, totalCommands int, cmd interface{}) int {
fmt.Fprintf(out, stepFormat, currentCommandIndex, totalCommands, cmd)
fmt.Fprintln(out)
return currentCommandIndex + 1
}
func (b *Builder) dispatchDockerfileWithCancellation(ctx context.Context, parseResult []instructions.Stage, metaArgs []instructions.ArgCommand, escapeToken rune, source builder.Source) (*dispatchState, error) {
dispatchRequest := dispatchRequest{}
buildArgs := NewBuildArgs(b.options.BuildArgs)
totalCommands := len(metaArgs) + len(parseResult)
currentCommandIndex := 1
for _, stage := range parseResult {
totalCommands += len(stage.Commands)
}
shlex := shell.NewLex(escapeToken)
for i := range metaArgs {
currentCommandIndex = printCommand(b.Stdout, currentCommandIndex, totalCommands, &metaArgs[i])
err := processMetaArg(metaArgs[i], shlex, buildArgs)
if err != nil {
return nil, err
}
}
stagesResults := newStagesBuildResults()
for _, s := range parseResult {
stage := s
if err := stagesResults.checkStageNameAvailable(stage.Name); err != nil {
return nil, err
}
dispatchRequest = newDispatchRequest(b, escapeToken, source, buildArgs, stagesResults)
currentCommandIndex = printCommand(b.Stdout, currentCommandIndex, totalCommands, stage.SourceCode)
if err := initializeStage(ctx, dispatchRequest, &stage); err != nil {
return nil, err
}
dispatchRequest.state.updateRunConfig()
fmt.Fprintf(b.Stdout, " ---> %s\n", stringid.TruncateID(dispatchRequest.state.imageID))
for _, cmd := range stage.Commands {
select {
case <-ctx.Done():
log.G(ctx).Debug("Builder: build cancelled!")
fmt.Fprint(b.Stdout, "Build cancelled\n")
buildsFailed.WithValues(metricsBuildCanceled).Inc()
return nil, errors.New("Build cancelled")
default:
// Not cancelled yet, keep going...
}
currentCommandIndex = printCommand(b.Stdout, currentCommandIndex, totalCommands, cmd)
if err := dispatch(ctx, dispatchRequest, cmd); err != nil {
return nil, err
}
dispatchRequest.state.updateRunConfig()
fmt.Fprintf(b.Stdout, " ---> %s\n", stringid.TruncateID(dispatchRequest.state.imageID))
}
if err := emitImageID(b.Aux, dispatchRequest.state); err != nil {
return nil, err
}
buildArgs.MergeReferencedArgs(dispatchRequest.state.buildArgs)
if err := commitStage(dispatchRequest.state, stagesResults); err != nil {
return nil, err
}
}
buildArgs.WarnOnUnusedBuildArgs(b.Stdout)
return dispatchRequest.state, nil
}
// BuildFromConfig builds directly from `changes`, treating it as if it were the contents of a Dockerfile
// It will:
// - Call parse.Parse() to get an AST root for the concatenated Dockerfile entries.
// - Do build by calling builder.dispatch() to call all entries' handling routines
//
// BuildFromConfig is used by the /commit endpoint, with the changes
// coming from the query parameter of the same name.
//
// TODO: Remove?
func BuildFromConfig(ctx context.Context, config *container.Config, changes []string, os string) (*container.Config, error) {
if len(changes) == 0 {
return config, nil
}
dockerfile, err := parser.Parse(bytes.NewBufferString(strings.Join(changes, "\n")))
if err != nil {
return nil, errdefs.InvalidParameter(err)
}
b, err := newBuilder(ctx, builderOptions{
Options: &types.ImageBuildOptions{NoCache: true},
})
if err != nil {
return nil, err
}
// ensure that the commands are valid
for _, n := range dockerfile.AST.Children {
if !validCommitCommands[strings.ToLower(n.Value)] {
return nil, errdefs.InvalidParameter(errors.Errorf("%s is not a valid change command", n.Value))
}
}
b.Stdout = io.Discard
b.Stderr = io.Discard
b.disableCommit = true
var commands []instructions.Command
for _, n := range dockerfile.AST.Children {
cmd, err := instructions.ParseCommand(n)
if err != nil {
return nil, errdefs.InvalidParameter(err)
}
commands = append(commands, cmd)
}
dispatchRequest := newDispatchRequest(b, dockerfile.EscapeToken, nil, NewBuildArgs(b.options.BuildArgs), newStagesBuildResults())
// We make mutations to the configuration, ensure we have a copy
dispatchRequest.state.runConfig = copyRunConfig(config)
dispatchRequest.state.imageID = config.Image
dispatchRequest.state.operatingSystem = os
for _, cmd := range commands {
err := dispatch(ctx, dispatchRequest, cmd)
if err != nil {
return nil, errdefs.InvalidParameter(err)
}
dispatchRequest.state.updateRunConfig()
}
return dispatchRequest.state.runConfig, nil
}
func convertMapToEnvList(m map[string]string) []string {
result := []string{}
for k, v := range m {
result = append(result, k+"="+v)
}
return result
}
// convertKVStringsToMap converts ["key=value"] to {"key":"value"}
func convertKVStringsToMap(values []string) map[string]string {
result := make(map[string]string, len(values))
for _, value := range values {
k, v, _ := strings.Cut(value, "=")
result[k] = v
}
return result
}