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moby--moby/builder/dockerfile/dispatchers.go
John Howard d98ecf2d6c LCOW: API change JSON header to string POST parameter
Signed-off-by: John Howard <jhoward@microsoft.com>
2017-10-06 15:26:48 -07:00

541 lines
17 KiB
Go

package dockerfile
// This file contains the dispatchers for each command. Note that
// `nullDispatch` is not actually a command, but support for commands we parse
// but do nothing with.
//
// See evaluator.go for a higher level discussion of the whole evaluator
// package.
import (
"bytes"
"fmt"
"runtime"
"sort"
"strings"
"github.com/docker/docker/api"
"github.com/docker/docker/api/types/container"
"github.com/docker/docker/api/types/strslice"
"github.com/docker/docker/builder"
"github.com/docker/docker/builder/dockerfile/instructions"
"github.com/docker/docker/builder/dockerfile/parser"
"github.com/docker/docker/image"
"github.com/docker/docker/pkg/jsonmessage"
"github.com/docker/docker/pkg/signal"
"github.com/docker/docker/pkg/system"
"github.com/docker/go-connections/nat"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
)
// ENV foo bar
//
// Sets the environment variable foo to bar, also makes interpolation
// in the dockerfile available from the next statement on via ${foo}.
//
func dispatchEnv(d dispatchRequest, c *instructions.EnvCommand) error {
runConfig := d.state.runConfig
commitMessage := bytes.NewBufferString("ENV")
for _, e := range c.Env {
name := e.Key
newVar := e.String()
commitMessage.WriteString(" " + newVar)
gotOne := false
for i, envVar := range runConfig.Env {
envParts := strings.SplitN(envVar, "=", 2)
compareFrom := envParts[0]
if equalEnvKeys(compareFrom, name) {
runConfig.Env[i] = newVar
gotOne = true
break
}
}
if !gotOne {
runConfig.Env = append(runConfig.Env, newVar)
}
}
return d.builder.commit(d.state, commitMessage.String())
}
// MAINTAINER some text <maybe@an.email.address>
//
// Sets the maintainer metadata.
func dispatchMaintainer(d dispatchRequest, c *instructions.MaintainerCommand) error {
d.state.maintainer = c.Maintainer
return d.builder.commit(d.state, "MAINTAINER "+c.Maintainer)
}
// LABEL some json data describing the image
//
// Sets the Label variable foo to bar,
//
func dispatchLabel(d dispatchRequest, c *instructions.LabelCommand) error {
if d.state.runConfig.Labels == nil {
d.state.runConfig.Labels = make(map[string]string)
}
commitStr := "LABEL"
for _, v := range c.Labels {
d.state.runConfig.Labels[v.Key] = v.Value
commitStr += " " + v.String()
}
return d.builder.commit(d.state, commitStr)
}
// ADD foo /path
//
// Add the file 'foo' to '/path'. Tarball and Remote URL (git, http) handling
// exist here. If you do not wish to have this automatic handling, use COPY.
//
func dispatchAdd(d dispatchRequest, c *instructions.AddCommand) error {
downloader := newRemoteSourceDownloader(d.builder.Output, d.builder.Stdout)
copier := copierFromDispatchRequest(d, downloader, nil)
defer copier.Cleanup()
copyInstruction, err := copier.createCopyInstruction(c.SourcesAndDest, "ADD")
if err != nil {
return err
}
copyInstruction.chownStr = c.Chown
copyInstruction.allowLocalDecompression = true
return d.builder.performCopy(d.state, copyInstruction)
}
// COPY foo /path
//
// Same as 'ADD' but without the tar and remote url handling.
//
func dispatchCopy(d dispatchRequest, c *instructions.CopyCommand) error {
var im *imageMount
var err error
if c.From != "" {
im, err = d.getImageMount(c.From)
if err != nil {
return errors.Wrapf(err, "invalid from flag value %s", c.From)
}
}
copier := copierFromDispatchRequest(d, errOnSourceDownload, im)
defer copier.Cleanup()
copyInstruction, err := copier.createCopyInstruction(c.SourcesAndDest, "COPY")
if err != nil {
return err
}
copyInstruction.chownStr = c.Chown
return d.builder.performCopy(d.state, copyInstruction)
}
func (d *dispatchRequest) getImageMount(imageRefOrID string) (*imageMount, error) {
if imageRefOrID == "" {
// TODO: this could return the source in the default case as well?
return nil, nil
}
var localOnly bool
stage, err := d.stages.get(imageRefOrID)
if err != nil {
return nil, err
}
if stage != nil {
imageRefOrID = stage.Image
localOnly = true
}
return d.builder.imageSources.Get(imageRefOrID, localOnly)
}
// FROM imagename[:tag | @digest] [AS build-stage-name]
//
func initializeStage(d dispatchRequest, cmd *instructions.Stage) error {
d.builder.imageProber.Reset()
image, err := d.getFromImage(d.shlex, cmd.BaseName)
if err != nil {
return err
}
state := d.state
state.beginStage(cmd.Name, image)
if len(state.runConfig.OnBuild) > 0 {
triggers := state.runConfig.OnBuild
state.runConfig.OnBuild = nil
return dispatchTriggeredOnBuild(d, triggers)
}
return nil
}
func dispatchTriggeredOnBuild(d dispatchRequest, triggers []string) error {
fmt.Fprintf(d.builder.Stdout, "# Executing %d build trigger", len(triggers))
if len(triggers) > 1 {
fmt.Fprint(d.builder.Stdout, "s")
}
fmt.Fprintln(d.builder.Stdout)
for _, trigger := range triggers {
d.state.updateRunConfig()
ast, err := parser.Parse(strings.NewReader(trigger))
if err != nil {
return err
}
if len(ast.AST.Children) != 1 {
return errors.New("onbuild trigger should be a single expression")
}
cmd, err := instructions.ParseCommand(ast.AST.Children[0])
if err != nil {
if instructions.IsUnknownInstruction(err) {
buildsFailed.WithValues(metricsUnknownInstructionError).Inc()
}
return err
}
err = dispatch(d, cmd)
if err != nil {
return err
}
}
return nil
}
func (d *dispatchRequest) getExpandedImageName(shlex *ShellLex, name string) (string, error) {
substitutionArgs := []string{}
for key, value := range d.state.buildArgs.GetAllMeta() {
substitutionArgs = append(substitutionArgs, key+"="+value)
}
name, err := shlex.ProcessWord(name, substitutionArgs)
if err != nil {
return "", err
}
return name, nil
}
func (d *dispatchRequest) getImageOrStage(name string) (builder.Image, error) {
var localOnly bool
if im, ok := d.stages.getByName(name); ok {
name = im.Image
localOnly = true
}
// Windows cannot support a container with no base image unless it is LCOW.
if name == api.NoBaseImageSpecifier {
imageImage := &image.Image{}
imageImage.OS = runtime.GOOS
if runtime.GOOS == "windows" {
optionsOS := system.ParsePlatform(d.builder.options.Platform).OS
switch optionsOS {
case "windows", "":
return nil, errors.New("Windows does not support FROM scratch")
case "linux":
if !system.LCOWSupported() {
return nil, errors.New("Linux containers are not supported on this system")
}
imageImage.OS = "linux"
default:
return nil, errors.Errorf("operating system %q is not supported", optionsOS)
}
}
return builder.Image(imageImage), nil
}
imageMount, err := d.builder.imageSources.Get(name, localOnly)
if err != nil {
return nil, err
}
return imageMount.Image(), nil
}
func (d *dispatchRequest) getFromImage(shlex *ShellLex, name string) (builder.Image, error) {
name, err := d.getExpandedImageName(shlex, name)
if err != nil {
return nil, err
}
return d.getImageOrStage(name)
}
func dispatchOnbuild(d dispatchRequest, c *instructions.OnbuildCommand) error {
d.state.runConfig.OnBuild = append(d.state.runConfig.OnBuild, c.Expression)
return d.builder.commit(d.state, "ONBUILD "+c.Expression)
}
// WORKDIR /tmp
//
// Set the working directory for future RUN/CMD/etc statements.
//
func dispatchWorkdir(d dispatchRequest, c *instructions.WorkdirCommand) error {
runConfig := d.state.runConfig
var err error
optionsOS := system.ParsePlatform(d.builder.options.Platform).OS
runConfig.WorkingDir, err = normalizeWorkdir(optionsOS, runConfig.WorkingDir, c.Path)
if err != nil {
return err
}
// For performance reasons, we explicitly do a create/mkdir now
// This avoids having an unnecessary expensive mount/unmount calls
// (on Windows in particular) during each container create.
// Prior to 1.13, the mkdir was deferred and not executed at this step.
if d.builder.disableCommit {
// Don't call back into the daemon if we're going through docker commit --change "WORKDIR /foo".
// We've already updated the runConfig and that's enough.
return nil
}
comment := "WORKDIR " + runConfig.WorkingDir
runConfigWithCommentCmd := copyRunConfig(runConfig, withCmdCommentString(comment, optionsOS))
containerID, err := d.builder.probeAndCreate(d.state, runConfigWithCommentCmd)
if err != nil || containerID == "" {
return err
}
if err := d.builder.docker.ContainerCreateWorkdir(containerID); err != nil {
return err
}
return d.builder.commitContainer(d.state, containerID, runConfigWithCommentCmd)
}
func resolveCmdLine(cmd instructions.ShellDependantCmdLine, runConfig *container.Config, platform string) []string {
result := cmd.CmdLine
if cmd.PrependShell && result != nil {
result = append(getShell(runConfig, platform), result...)
}
return result
}
// RUN some command yo
//
// run a command and commit the image. Args are automatically prepended with
// the current SHELL which defaults to 'sh -c' under linux or 'cmd /S /C' under
// Windows, in the event there is only one argument The difference in processing:
//
// RUN echo hi # sh -c echo hi (Linux and LCOW)
// RUN echo hi # cmd /S /C echo hi (Windows)
// RUN [ "echo", "hi" ] # echo hi
//
func dispatchRun(d dispatchRequest, c *instructions.RunCommand) error {
stateRunConfig := d.state.runConfig
optionsOS := system.ParsePlatform(d.builder.options.Platform).OS
cmdFromArgs := resolveCmdLine(c.ShellDependantCmdLine, stateRunConfig, optionsOS)
buildArgs := d.state.buildArgs.FilterAllowed(stateRunConfig.Env)
saveCmd := cmdFromArgs
if len(buildArgs) > 0 {
saveCmd = prependEnvOnCmd(d.state.buildArgs, buildArgs, cmdFromArgs)
}
runConfigForCacheProbe := copyRunConfig(stateRunConfig,
withCmd(saveCmd),
withEntrypointOverride(saveCmd, nil))
hit, err := d.builder.probeCache(d.state, runConfigForCacheProbe)
if err != nil || hit {
return err
}
runConfig := copyRunConfig(stateRunConfig,
withCmd(cmdFromArgs),
withEnv(append(stateRunConfig.Env, buildArgs...)),
withEntrypointOverride(saveCmd, strslice.StrSlice{""}))
// set config as already being escaped, this prevents double escaping on windows
runConfig.ArgsEscaped = true
logrus.Debugf("[BUILDER] Command to be executed: %v", runConfig.Cmd)
cID, err := d.builder.create(runConfig)
if err != nil {
return err
}
if err := d.builder.containerManager.Run(d.builder.clientCtx, cID, d.builder.Stdout, d.builder.Stderr); err != nil {
if err, ok := err.(*statusCodeError); ok {
// TODO: change error type, because jsonmessage.JSONError assumes HTTP
return &jsonmessage.JSONError{
Message: fmt.Sprintf(
"The command '%s' returned a non-zero code: %d",
strings.Join(runConfig.Cmd, " "), err.StatusCode()),
Code: err.StatusCode(),
}
}
return err
}
return d.builder.commitContainer(d.state, cID, runConfigForCacheProbe)
}
// Derive the command to use for probeCache() and to commit in this container.
// Note that we only do this if there are any build-time env vars. Also, we
// use the special argument "|#" at the start of the args array. This will
// avoid conflicts with any RUN command since commands can not
// start with | (vertical bar). The "#" (number of build envs) is there to
// help ensure proper cache matches. We don't want a RUN command
// that starts with "foo=abc" to be considered part of a build-time env var.
//
// remove any unreferenced built-in args from the environment variables.
// These args are transparent so resulting image should be the same regardless
// of the value.
func prependEnvOnCmd(buildArgs *buildArgs, buildArgVars []string, cmd strslice.StrSlice) strslice.StrSlice {
var tmpBuildEnv []string
for _, env := range buildArgVars {
key := strings.SplitN(env, "=", 2)[0]
if buildArgs.IsReferencedOrNotBuiltin(key) {
tmpBuildEnv = append(tmpBuildEnv, env)
}
}
sort.Strings(tmpBuildEnv)
tmpEnv := append([]string{fmt.Sprintf("|%d", len(tmpBuildEnv))}, tmpBuildEnv...)
return strslice.StrSlice(append(tmpEnv, cmd...))
}
// CMD foo
//
// Set the default command to run in the container (which may be empty).
// Argument handling is the same as RUN.
//
func dispatchCmd(d dispatchRequest, c *instructions.CmdCommand) error {
runConfig := d.state.runConfig
optionsOS := system.ParsePlatform(d.builder.options.Platform).OS
cmd := resolveCmdLine(c.ShellDependantCmdLine, runConfig, optionsOS)
runConfig.Cmd = cmd
// set config as already being escaped, this prevents double escaping on windows
runConfig.ArgsEscaped = true
if err := d.builder.commit(d.state, fmt.Sprintf("CMD %q", cmd)); err != nil {
return err
}
if len(c.ShellDependantCmdLine.CmdLine) != 0 {
d.state.cmdSet = true
}
return nil
}
// HEALTHCHECK foo
//
// Set the default healthcheck command to run in the container (which may be empty).
// Argument handling is the same as RUN.
//
func dispatchHealthcheck(d dispatchRequest, c *instructions.HealthCheckCommand) error {
runConfig := d.state.runConfig
if runConfig.Healthcheck != nil {
oldCmd := runConfig.Healthcheck.Test
if len(oldCmd) > 0 && oldCmd[0] != "NONE" {
fmt.Fprintf(d.builder.Stdout, "Note: overriding previous HEALTHCHECK: %v\n", oldCmd)
}
}
runConfig.Healthcheck = c.Health
return d.builder.commit(d.state, fmt.Sprintf("HEALTHCHECK %q", runConfig.Healthcheck))
}
// ENTRYPOINT /usr/sbin/nginx
//
// Set the entrypoint to /usr/sbin/nginx. Will accept the CMD as the arguments
// to /usr/sbin/nginx. Uses the default shell if not in JSON format.
//
// Handles command processing similar to CMD and RUN, only req.runConfig.Entrypoint
// is initialized at newBuilder time instead of through argument parsing.
//
func dispatchEntrypoint(d dispatchRequest, c *instructions.EntrypointCommand) error {
runConfig := d.state.runConfig
optionsOS := system.ParsePlatform(d.builder.options.Platform).OS
cmd := resolveCmdLine(c.ShellDependantCmdLine, runConfig, optionsOS)
runConfig.Entrypoint = cmd
if !d.state.cmdSet {
runConfig.Cmd = nil
}
return d.builder.commit(d.state, fmt.Sprintf("ENTRYPOINT %q", runConfig.Entrypoint))
}
// EXPOSE 6667/tcp 7000/tcp
//
// Expose ports for links and port mappings. This all ends up in
// req.runConfig.ExposedPorts for runconfig.
//
func dispatchExpose(d dispatchRequest, c *instructions.ExposeCommand, envs []string) error {
// custom multi word expansion
// expose $FOO with FOO="80 443" is expanded as EXPOSE [80,443]. This is the only command supporting word to words expansion
// so the word processing has been de-generalized
ports := []string{}
for _, p := range c.Ports {
ps, err := d.shlex.ProcessWords(p, envs)
if err != nil {
return err
}
ports = append(ports, ps...)
}
c.Ports = ports
ps, _, err := nat.ParsePortSpecs(ports)
if err != nil {
return err
}
if d.state.runConfig.ExposedPorts == nil {
d.state.runConfig.ExposedPorts = make(nat.PortSet)
}
for p := range ps {
d.state.runConfig.ExposedPorts[p] = struct{}{}
}
return d.builder.commit(d.state, "EXPOSE "+strings.Join(c.Ports, " "))
}
// USER foo
//
// Set the user to 'foo' for future commands and when running the
// ENTRYPOINT/CMD at container run time.
//
func dispatchUser(d dispatchRequest, c *instructions.UserCommand) error {
d.state.runConfig.User = c.User
return d.builder.commit(d.state, fmt.Sprintf("USER %v", c.User))
}
// VOLUME /foo
//
// Expose the volume /foo for use. Will also accept the JSON array form.
//
func dispatchVolume(d dispatchRequest, c *instructions.VolumeCommand) error {
if d.state.runConfig.Volumes == nil {
d.state.runConfig.Volumes = map[string]struct{}{}
}
for _, v := range c.Volumes {
if v == "" {
return errors.New("VOLUME specified can not be an empty string")
}
d.state.runConfig.Volumes[v] = struct{}{}
}
return d.builder.commit(d.state, fmt.Sprintf("VOLUME %v", c.Volumes))
}
// STOPSIGNAL signal
//
// Set the signal that will be used to kill the container.
func dispatchStopSignal(d dispatchRequest, c *instructions.StopSignalCommand) error {
_, err := signal.ParseSignal(c.Signal)
if err != nil {
return validationError{err}
}
d.state.runConfig.StopSignal = c.Signal
return d.builder.commit(d.state, fmt.Sprintf("STOPSIGNAL %v", c.Signal))
}
// ARG name[=value]
//
// Adds the variable foo to the trusted list of variables that can be passed
// to builder using the --build-arg flag for expansion/substitution or passing to 'run'.
// Dockerfile author may optionally set a default value of this variable.
func dispatchArg(d dispatchRequest, c *instructions.ArgCommand) error {
commitStr := "ARG " + c.Key
if c.Value != nil {
commitStr += "=" + *c.Value
}
d.state.buildArgs.AddArg(c.Key, c.Value)
return d.builder.commit(d.state, commitStr)
}
// SHELL powershell -command
//
// Set the non-default shell to use.
func dispatchShell(d dispatchRequest, c *instructions.ShellCommand) error {
d.state.runConfig.Shell = c.Shell
return d.builder.commit(d.state, fmt.Sprintf("SHELL %v", d.state.runConfig.Shell))
}