buildx/build/opt.go

package build

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"io/fs"
	"maps"
	"os"
	"path"
	"path/filepath"
	"slices"
	"strconv"
	"strings"
	"sync"
	"syscall"
	"time"

	awsconfig "github.com/aws/aws-sdk-go-v2/config"
	"github.com/containerd/console"
	"github.com/containerd/containerd/v2/core/content"
	"github.com/containerd/containerd/v2/plugins/content/local"
	"github.com/containerd/platforms"
	"github.com/distribution/reference"
	"github.com/docker/buildx/builder"
	"github.com/docker/buildx/driver"
	"github.com/docker/buildx/policy"
	"github.com/docker/buildx/util/buildflags"
	"github.com/docker/buildx/util/confutil"
	"github.com/docker/buildx/util/dockerutil"
	"github.com/docker/buildx/util/osutil"
	"github.com/docker/buildx/util/progress"
	"github.com/moby/buildkit/client"
	"github.com/moby/buildkit/client/llb"
	"github.com/moby/buildkit/client/ociindex"
	"github.com/moby/buildkit/exporter/containerimage/exptypes"
	"github.com/moby/buildkit/frontend/dockerui"
	gateway "github.com/moby/buildkit/frontend/gateway/client"
	"github.com/moby/buildkit/identity"
	"github.com/moby/buildkit/session"
	"github.com/moby/buildkit/session/secrets/secretsprovider"
	"github.com/moby/buildkit/session/sshforward/sshprovider"
	"github.com/moby/buildkit/session/upload/uploadprovider"
	"github.com/moby/buildkit/solver/pb"
	"github.com/moby/buildkit/sourcepolicy/policysession"
	"github.com/moby/buildkit/util/apicaps"
	"github.com/moby/buildkit/util/entitlements"
	"github.com/moby/buildkit/util/gitutil"
	"github.com/opencontainers/go-digest"
	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
	"github.com/tonistiigi/fsutil"
)

var sendGitQueryAsInput = sync.OnceValue(func() bool {
	if v, ok := os.LookupEnv("BUILDX_SEND_GIT_QUERY_AS_INPUT"); ok {
		if vv, err := strconv.ParseBool(v); err == nil {
			return vv
		}
	}
	return false
})

type policyProgressLogger struct {
	ch      chan *client.SolveStatus
	done    chan struct{}
	dgst    digest.Digest
	name    string
	started time.Time
	mu      sync.Mutex
	timer   *time.Timer
	window  int
	open    bool
	closed  bool
}

const policyProgressWindow = 500 * time.Millisecond

func newPolicyProgressLogger(pw progress.Writer, name string) *policyProgressLogger {
	if pw == nil {
		return nil
	}
	ch, done := progress.NewChannel(pw)
	dgst := digest.FromBytes([]byte(identity.NewID()))
	return &policyProgressLogger{
		ch:   ch,
		done: done,
		dgst: dgst,
		name: name,
	}
}

func (l *policyProgressLogger) Log(msg string) {
	if l == nil || msg == "" {
		return
	}
	needStart := false
	var started time.Time
	var window int

	l.mu.Lock()
	if l.closed {
		l.mu.Unlock()
		return
	}
	if !l.open {
		needStart = true
		l.open = true
		l.window++
		window = l.window
		started = time.Now()
		l.started = started
	} else {
		window = l.window
	}
	if l.timer != nil {
		l.timer.Stop()
	}
	l.timer = time.AfterFunc(policyProgressWindow, func() {
		l.completeWindow(window, nil)
	})
	if needStart {
		l.sendVertexStart(started)
	}
	if !strings.HasSuffix(msg, "\n") {
		msg += "\n"
	}
	l.ch <- &client.SolveStatus{
		Logs: []*client.VertexLog{{
			Vertex:    l.dgst,
			Stream:    1,
			Data:      []byte(msg),
			Timestamp: time.Now(),
		}},
	}
	l.mu.Unlock()
}

func (l *policyProgressLogger) Write(p []byte) (int, error) {
	if len(p) > 0 {
		l.Log(string(p))
	}
	return len(p), nil
}

func (l *policyProgressLogger) Close(err error) {
	if l == nil {
		return
	}
	shouldComplete := false
	var started time.Time

	l.mu.Lock()
	if l.closed {
		l.mu.Unlock()
		return
	}
	l.closed = true
	if l.open {
		shouldComplete = true
		started = l.started
		l.open = false
	}
	l.window++
	if l.timer != nil {
		l.timer.Stop()
		l.timer = nil
	}
	if shouldComplete {
		l.sendVertexComplete(started, err)
	}
	l.mu.Unlock()
	close(l.ch)
	<-l.done
}

func (l *policyProgressLogger) completeWindow(window int, err error) {
	l.mu.Lock()
	if l.closed || !l.open || window != l.window {
		l.mu.Unlock()
		return
	}
	started := l.started
	l.open = false
	l.sendVertexComplete(started, err)
	l.mu.Unlock()
}

func (l *policyProgressLogger) sendVertexStart(started time.Time) {
	vtx := client.Vertex{
		Digest:  l.dgst,
		Name:    l.name,
		Started: &started,
	}
	l.ch <- &client.SolveStatus{Vertexes: []*client.Vertex{&vtx}}
}

func (l *policyProgressLogger) sendVertexComplete(started time.Time, err error) {
	tm := time.Now()
	vtx := client.Vertex{
		Digest:    l.dgst,
		Name:      l.name,
		Started:   &started,
		Completed: &tm,
	}
	if err != nil {
		vtx.Error = err.Error()
	}
	l.ch <- &client.SolveStatus{Vertexes: []*client.Vertex{&vtx}}
}

func toSolveOpt(ctx context.Context, node builder.Node, multiDriver bool, opt *Options, bopts gateway.BuildOpts, cfg *confutil.Config, pw progress.Writer, docker *dockerutil.Client) (_ *client.SolveOpt, release func(), err error) {
	nodeDriver := node.Driver
	defers := make([]func(), 0, 2)
	releaseF := func() {
		for _, f := range defers {
			f()
		}
	}

	defer func() {
		if err != nil {
			releaseF()
		}
	}()

	// inline cache from build arg
	if v, ok := opt.BuildArgs["BUILDKIT_INLINE_CACHE"]; ok {
		if v, _ := strconv.ParseBool(v); v {
			opt.CacheTo = append(opt.CacheTo, client.CacheOptionsEntry{
				Type:  "inline",
				Attrs: map[string]string{},
			})
		}
	}

	for _, e := range opt.CacheTo {
		if e.Type != "inline" && !nodeDriver.Features(ctx)[driver.CacheExport] {
			return nil, nil, notSupported(driver.CacheExport, nodeDriver, "https://docs.docker.com/go/build-cache-backends/")
		}
	}

	cacheTo := make([]client.CacheOptionsEntry, 0, len(opt.CacheTo))
	for _, e := range opt.CacheTo {
		if e.Type == "gha" {
			if !bopts.LLBCaps.Contains(apicaps.CapID("cache.gha")) {
				continue
			}
		} else if e.Type == "s3" {
			if !bopts.LLBCaps.Contains(apicaps.CapID("cache.s3")) {
				continue
			}
		}
		cacheTo = append(cacheTo, e)
	}

	cacheFrom := make([]client.CacheOptionsEntry, 0, len(opt.CacheFrom))
	for _, e := range opt.CacheFrom {
		if e.Type == "gha" {
			if !bopts.LLBCaps.Contains(apicaps.CapID("cache.gha")) {
				continue
			}
		} else if e.Type == "s3" {
			if !bopts.LLBCaps.Contains(apicaps.CapID("cache.s3")) {
				continue
			}
		}
		cacheFrom = append(cacheFrom, e)
	}

	so := client.SolveOpt{
		Ref:                 opt.Ref,
		Frontend:            "dockerfile.v0",
		FrontendAttrs:       map[string]string{},
		LocalMounts:         map[string]fsutil.FS{},
		CacheExports:        cacheTo,
		CacheImports:        cacheFrom,
		AllowedEntitlements: opt.Allow,
		SourcePolicy:        opt.SourcePolicy,
	}

	if opt.CgroupParent != "" {
		so.FrontendAttrs["cgroup-parent"] = opt.CgroupParent
	}

	if v, ok := opt.BuildArgs["BUILDKIT_SYNTAX"]; ok {
		p := strings.SplitN(strings.TrimSpace(v), " ", 2)
		so.Frontend = "gateway.v0"
		so.FrontendAttrs["source"] = p[0]
		so.FrontendAttrs["cmdline"] = v
	}

	if v, ok := opt.BuildArgs["BUILDKIT_MULTI_PLATFORM"]; ok {
		if v, _ := strconv.ParseBool(v); v {
			so.FrontendAttrs["multi-platform"] = "true"
		}
	}

	if multiDriver {
		// force creation of manifest list
		so.FrontendAttrs["multi-platform"] = "true"
	}

	attests := make(map[string]string)
	for k, v := range opt.Attests {
		if v != nil {
			attests[k] = *v
		}
	}

	supportAttestations := bopts.LLBCaps.Contains(apicaps.CapID("exporter.image.attestations")) && nodeDriver.Features(ctx)[driver.MultiPlatform]
	if len(attests) > 0 {
		if !supportAttestations {
			if !nodeDriver.Features(ctx)[driver.MultiPlatform] {
				return nil, nil, notSupported("Attestation", nodeDriver, "https://docs.docker.com/go/attestations/")
			}
			return nil, nil, errors.Errorf("Attestations are not supported by the current BuildKit daemon")
		}
		for k, v := range attests {
			so.FrontendAttrs["attest:"+k] = v
		}
	}

	if _, ok := opt.Attests["provenance"]; !ok && supportAttestations {
		const noAttestEnv = "BUILDX_NO_DEFAULT_ATTESTATIONS"
		var noProv bool
		if v, ok := os.LookupEnv(noAttestEnv); ok {
			noProv, err = strconv.ParseBool(v)
			if err != nil {
				return nil, nil, errors.Wrap(err, "invalid "+noAttestEnv)
			}
		}
		if !noProv {
			so.FrontendAttrs["attest:provenance"] = "mode=min,inline-only=true"
		}
	}

	switch len(opt.Exports) {
	case 1:
		// valid
	case 0:
		if !noDefaultLoad() && opt.CallFunc == nil {
			if nodeDriver.IsMobyDriver() {
				// backwards compat for docker driver only:
				// this ensures the build results in a docker image.
				opt.Exports = []client.ExportEntry{{Type: "image", Attrs: map[string]string{}}}
			} else if nodeDriver.Features(ctx)[driver.DefaultLoad] {
				opt.Exports = []client.ExportEntry{{Type: "docker", Attrs: map[string]string{}}}
			}
		}
	default:
		if err := bopts.LLBCaps.Supports(pb.CapMultipleExporters); err != nil {
			return nil, nil, errors.Errorf("multiple outputs currently unsupported by the current BuildKit daemon, please upgrade to version v0.13+ or use a single output")
		}
	}

	// check if index annotations are supported by docker driver
	if len(opt.Exports) > 0 && opt.CallFunc == nil && len(opt.Annotations) > 0 && nodeDriver.IsMobyDriver() && !nodeDriver.Features(ctx)[driver.MultiPlatform] {
		for _, exp := range opt.Exports {
			if exp.Type == "image" || exp.Type == "docker" {
				for ak := range opt.Annotations {
					switch ak.Type {
					case exptypes.AnnotationIndex, exptypes.AnnotationIndexDescriptor:
						return nil, nil, errors.New("index annotations not supported for single platform export")
					}
				}
			}
		}
	}

	// fill in image exporter names from tags
	if len(opt.Tags) > 0 {
		tags := make([]string, len(opt.Tags))
		for i, tag := range opt.Tags {
			ref, err := reference.Parse(tag)
			if err != nil {
				return nil, nil, errors.Wrapf(err, "invalid tag %q", tag)
			}
			tags[i] = ref.String()
		}
		for i, e := range opt.Exports {
			switch e.Type {
			case "image", "oci", "docker":
				opt.Exports[i].Attrs["name"] = strings.Join(tags, ",")
			}
		}
	} else {
		for _, e := range opt.Exports {
			if e.Type == "image" && e.Attrs["name"] == "" && e.Attrs["push"] != "" {
				if ok, _ := strconv.ParseBool(e.Attrs["push"]); ok {
					return nil, nil, errors.Errorf("tag is needed when pushing to registry")
				}
			}
		}
	}

	// cacheonly is a fake exporter to opt out of default behaviors
	exports := make([]client.ExportEntry, 0, len(opt.Exports))
	for _, e := range opt.Exports {
		if e.Type != "cacheonly" {
			exports = append(exports, e)
		}
	}
	opt.Exports = exports

	// set up exporters
	for i, e := range opt.Exports {
		if e.Type == "oci" && !nodeDriver.Features(ctx)[driver.OCIExporter] {
			return nil, nil, notSupported(driver.OCIExporter, nodeDriver, "https://docs.docker.com/go/build-exporters/")
		}
		if e.Type == "docker" {
			features := docker.Features(ctx, e.Attrs["context"])
			if features[dockerutil.OCIImporter] && e.Output == nil {
				// rely on oci importer if available (which supports
				// multi-platform images), otherwise fall back to docker
				opt.Exports[i].Type = "oci"
			} else if len(opt.Platforms) > 1 || len(attests) > 0 {
				if e.Output != nil {
					return nil, nil, errors.Errorf("docker exporter does not support exporting manifest lists, use the oci exporter instead")
				}
				return nil, nil, errors.Errorf("docker exporter does not currently support exporting manifest lists")
			}
			if e.Output == nil {
				if nodeDriver.IsMobyDriver() {
					e.Type = "image"
				} else {
					w, cancel, err := docker.LoadImage(ctx, e.Attrs["context"], pw)
					if err != nil {
						return nil, nil, err
					}
					defers = append(defers, cancel)
					opt.Exports[i].Output = func(_ map[string]string) (io.WriteCloser, error) {
						return w, nil
					}
					// if docker is using the containerd snapshotter, prefer to export the image digest
					// (rather than the image config digest). See https://github.com/moby/moby/issues/45458.
					if features[dockerutil.OCIImporter] {
						opt.Exports[i].Attrs["prefer-image-digest"] = "true"
					}
				}
			} else if !nodeDriver.Features(ctx)[driver.DockerExporter] {
				return nil, nil, notSupported(driver.DockerExporter, nodeDriver, "https://docs.docker.com/go/build-exporters/")
			}
		}
		if e.Type == "image" && nodeDriver.IsMobyDriver() {
			opt.Exports[i].Type = "moby"
			if e.Attrs["push"] != "" {
				if ok, _ := strconv.ParseBool(e.Attrs["push"]); ok {
					if ok, _ := strconv.ParseBool(e.Attrs["push-by-digest"]); ok {
						return nil, nil, errors.Errorf("push-by-digest is currently not implemented for docker driver, please create a new builder instance")
					}
				}
			}
		}
		if e.Type == "docker" || e.Type == "image" || e.Type == "oci" {
			// inline buildinfo attrs from build arg
			if v, ok := opt.BuildArgs["BUILDKIT_INLINE_BUILDINFO_ATTRS"]; ok {
				opt.Exports[i].Attrs["buildinfo-attrs"] = v
			}
		}
	}

	so.Exports = opt.Exports
	so.Session = slices.Clone(opt.Session)

	for k, v := range opt.BuildArgs {
		so.FrontendAttrs["build-arg:"+k] = v
	}
	for k, v := range opt.Labels {
		so.FrontendAttrs["label:"+k] = v
	}

	releaseLoad, err := loadInputs(ctx, nodeDriver, &opt.Inputs, pw, &so)
	if err != nil {
		return nil, nil, err
	}
	defers = append(defers, releaseLoad)

	if opt.Inputs.policy == nil {
		if len(opt.Policy) > 0 {
			return nil, nil, errors.New("policy file specified but no policy FS in build context")
		}
	} else {
		env := policy.Env{}
		for k, v := range opt.BuildArgs {
			if env.Args == nil {
				env.Args = map[string]*string{}
			}
			env.Args[k] = &v
		}
		env.Filename = path.Base(opt.Inputs.DockerfilePath)
		env.Target = opt.Target
		env.Labels = opt.Labels

		popts, err := withPolicyConfig(*opt.Inputs.policy, opt.Policy)
		if err != nil {
			return nil, nil, err
		}
		var policyFiles []string
		for _, popt := range popts {
			for _, f := range popt.Files {
				if f.Filename != "" {
					policyFiles = append(policyFiles, f.Filename)
				}
			}
		}
		var policyLogger *policyProgressLogger
		if len(policyFiles) > 0 {
			policyLogger = newPolicyProgressLogger(pw, fmt.Sprintf("loading policies %s", strings.Join(policyFiles, ", ")))
		}
		if policyLogger != nil {
			defers = append(defers, func() {
				policyLogger.Close(nil)
			})
		}
		var cbs []policysession.PolicyCallback
		for _, popt := range popts {
			policyLevel := logrus.GetLevel()
			if popt.LogLevel != nil {
				policyLevel = *popt.LogLevel
			}
			logf := func(level logrus.Level, msg string) {
				if policyLogger == nil || level > policyLevel {
					return
				}
				policyLogger.Log(msg)
			}
			p := policy.NewPolicy(policy.Opt{
				Files:            popt.Files,
				Env:              env,
				Log:              logf,
				FS:               opt.Inputs.policy.FS,
				VerifierProvider: policy.SignatureVerifier(cfg),
				DefaultPlatform:  defaultPlatform(bopts),
			})
			cbs = append(cbs, p.CheckPolicy)
			if popt.Strict {
				if bopts.LLBCaps.Supports(pb.CapSourcePolicySession) != nil {
					return nil, nil, errors.New("strict policy is not supported by the current BuildKit daemon, please upgrade to version v0.27+")
				}
			}
		}
		so.SourcePolicyProvider = policysession.NewPolicyProvider(policy.MultiPolicyCallback(cbs...))
	}

	// add node identifier to shared key if one was specified
	nodeID := cfg.TryNodeIdentifier()
	if so.SharedKey != "" {
		so.SharedKey += ":" + nodeID
	}
	for k, v := range so.FrontendAttrs {
		if strings.HasPrefix(k, "sharedkey:localdir:") {
			so.FrontendAttrs[k] = v + ":" + nodeID
		}
	}

	if opt.Pull {
		so.FrontendAttrs["image-resolve-mode"] = pb.AttrImageResolveModeForcePull
	} else if nodeDriver.IsMobyDriver() {
		// moby driver always resolves local images by default
		so.FrontendAttrs["image-resolve-mode"] = pb.AttrImageResolveModePreferLocal
	}
	if opt.Target != "" {
		so.FrontendAttrs["target"] = opt.Target
	}
	if len(opt.NoCacheFilter) > 0 {
		so.FrontendAttrs["no-cache"] = strings.Join(opt.NoCacheFilter, ",")
	}
	if opt.NoCache {
		so.FrontendAttrs["no-cache"] = ""
	}

	for k, v := range node.ProxyConfig {
		if _, ok := opt.BuildArgs[k]; !ok {
			so.FrontendAttrs["build-arg:"+k] = v
		}
	}

	// set platforms
	if len(opt.Platforms) != 0 {
		pp := make([]string, len(opt.Platforms))
		for i, p := range opt.Platforms {
			pp[i] = platforms.Format(p)
		}
		if len(pp) > 1 && !nodeDriver.Features(ctx)[driver.MultiPlatform] {
			return nil, nil, notSupported(driver.MultiPlatform, nodeDriver, "https://docs.docker.com/go/build-multi-platform/")
		}
		so.FrontendAttrs["platform"] = strings.Join(pp, ",")
	}

	// setup networkmode
	switch opt.NetworkMode {
	case "host":
		so.FrontendAttrs["force-network-mode"] = opt.NetworkMode
		so.AllowedEntitlements = append(so.AllowedEntitlements, entitlements.EntitlementNetworkHost.String())
	case "none":
		so.FrontendAttrs["force-network-mode"] = opt.NetworkMode
	case "", "default":
	default:
		return nil, nil, errors.Errorf("network mode %q not supported by buildkit - you can define a custom network for your builder using the network driver-opt in buildx create", opt.NetworkMode)
	}

	// setup extrahosts
	extraHosts, err := toBuildkitExtraHosts(ctx, opt.ExtraHosts, nodeDriver)
	if err != nil {
		return nil, nil, err
	}
	if len(extraHosts) > 0 {
		so.FrontendAttrs["add-hosts"] = extraHosts
	}

	// setup shm size
	if opt.ShmSize.Value() > 0 {
		so.FrontendAttrs["shm-size"] = strconv.FormatInt(opt.ShmSize.Value(), 10)
	}

	// setup ulimits
	ulimits, err := toBuildkitUlimits(opt.Ulimits)
	if err != nil {
		return nil, nil, err
	} else if len(ulimits) > 0 {
		so.FrontendAttrs["ulimit"] = ulimits
	}

	// mark call request as internal
	if opt.CallFunc != nil {
		so.Internal = true
	}

	return &so, releaseF, nil
}

func loadInputs(ctx context.Context, d *driver.DriverHandle, inp *Inputs, pw progress.Writer, target *client.SolveOpt) (func(), error) {
	if inp.ContextPath == "" {
		return nil, errors.New("please specify build context (e.g. \".\" for the current directory)")
	}

	// TODO: handle stdin, symlinks, remote contexts, check files exist

	var (
		err               error
		dockerfileReader  io.ReadCloser
		contextDir        string
		dockerfileDir     string
		dockerfileName    = inp.DockerfilePath
		dockerfileSrcName = inp.DockerfilePath
		toRemove          []string
		caps              = map[string]struct{}{}
	)

	switch {
	case inp.ContextState != nil:
		if target.FrontendInputs == nil {
			target.FrontendInputs = make(map[string]llb.State)
		}
		target.FrontendInputs["context"] = *inp.ContextState
		target.FrontendInputs["dockerfile"] = *inp.ContextState
	case inp.ContextPath == "-":
		if inp.DockerfilePath == "-" {
			return nil, errors.Errorf("invalid argument: can't use stdin for both build context and dockerfile")
		}

		rc := inp.InStream.NewReadCloser()
		magic, err := inp.InStream.Peek(archiveHeaderSize * 2)
		if err != nil && err != io.EOF {
			return nil, errors.Wrap(err, "failed to peek context header from STDIN")
		}
		if err != io.EOF || len(magic) != 0 {
			if isArchive(magic) {
				// stdin is context
				up := uploadprovider.New()
				target.FrontendAttrs["context"] = up.Add(rc)
				target.Session = append(target.Session, up)
			} else {
				if inp.DockerfilePath != "" {
					return nil, errors.Errorf("ambiguous Dockerfile source: both stdin and flag correspond to Dockerfiles")
				}
				// stdin is dockerfile
				dockerfileReader = rc
				inp.ContextPath, _ = os.MkdirTemp("", "empty-dir")
				toRemove = append(toRemove, inp.ContextPath)
				if err := setLocalMount("context", inp.ContextPath, target); err != nil {
					return nil, err
				}
				contextDir = inp.ContextPath
			}
		}
	case osutil.IsLocalDir(inp.ContextPath):
		if err := setLocalMount("context", inp.ContextPath, target); err != nil {
			return nil, err
		}
		contextDir = inp.ContextPath
		sharedKey := inp.ContextPath
		if p, err := filepath.Abs(sharedKey); err == nil {
			sharedKey = filepath.Base(p)
		}
		target.SharedKey = sharedKey
		switch inp.DockerfilePath {
		case "-":
			dockerfileReader = inp.InStream.NewReadCloser()
		case "":
			dockerfileDir = inp.ContextPath
		default:
			dockerfileDir = filepath.Dir(inp.DockerfilePath)
			dockerfileName = filepath.Base(inp.DockerfilePath)
		}
	case IsRemoteURL(inp.ContextPath):
		if inp.DockerfilePath == "-" {
			dockerfileReader = inp.InStream.NewReadCloser()
		} else if filepath.IsAbs(inp.DockerfilePath) {
			dockerfileDir = filepath.Dir(inp.DockerfilePath)
			dockerfileName = filepath.Base(inp.DockerfilePath)
			target.FrontendAttrs["dockerfilekey"] = "dockerfile"
		}
		target.FrontendAttrs["context"] = inp.ContextPath

		if err := processGitURL(inp.ContextPath, "context", target, caps); err != nil {
			return nil, err
		}
		if st, ok := target.FrontendInputs["context"]; ok {
			if dockerfileReader == nil && !filepath.IsAbs(inp.DockerfilePath) {
				target.FrontendInputs["dockerfile"] = st
			}
		}

	default:
		return nil, errors.Errorf("unable to prepare context: path %q not found", inp.ContextPath)
	}

	if inp.DockerfileInline != "" {
		dockerfileReader = io.NopCloser(strings.NewReader(inp.DockerfileInline))
		dockerfileSrcName = "inline"
	} else if inp.DockerfilePath == "-" {
		dockerfileSrcName = "stdin"
	} else if inp.DockerfilePath == "" {
		dockerfileSrcName = filepath.Join(inp.ContextPath, "Dockerfile")
	}

	if dockerfileReader != nil {
		dockerfileDir, err = createTempDockerfile(dockerfileReader, inp.InStream)
		if err != nil {
			return nil, err
		}
		toRemove = append(toRemove, dockerfileDir)
		dockerfileName = "Dockerfile"
		target.FrontendAttrs["dockerfilekey"] = "dockerfile"
	}
	if isHTTPURL(inp.DockerfilePath) {
		dockerfileDir, err = createTempDockerfileFromURL(ctx, d, inp.DockerfilePath, pw)
		if err != nil {
			return nil, err
		}
		toRemove = append(toRemove, dockerfileDir)
		dockerfileName = "Dockerfile"
		target.FrontendAttrs["dockerfilekey"] = "dockerfile"
		delete(target.FrontendInputs, "dockerfile")
	}

	if dockerfileName == "" {
		dockerfileName = "Dockerfile"
	}

	p := &policyOpt{
		FS: func() (fs.StatFS, func() error, error) {
			if contextDir == "" {
				return nil, nil, errors.Errorf("unimplemented, cannot use policy file without a local build context")
			}
			root, err := os.OpenRoot(contextDir)
			if err != nil {
				return nil, nil, errors.Wrapf(err, "failed to open root for policy file %s.rego", dockerfileName)
			}
			baseFS := root.FS()
			statFS, ok := baseFS.(fs.StatFS)
			if !ok {
				root.Close()
				return nil, nil, errors.Errorf("invalid root FS type %T", baseFS)
			}
			return statFS, root.Close, nil
		},
	}

	if dockerfileDir != "" {
		if err := setLocalMount("dockerfile", dockerfileDir, target); err != nil {
			return nil, err
		}
		dockerfileName = handleLowercaseDockerfile(dockerfileDir, dockerfileName)

		if fi, err := os.Lstat(filepath.Join(dockerfileDir, dockerfileName+".rego")); err == nil {
			if fi.Mode().IsRegular() {
				dt, err := os.ReadFile(filepath.Join(dockerfileDir, dockerfileName+".rego"))
				if err != nil {
					return nil, errors.Wrapf(err, "failed to read policy file %s.rego", dockerfileName)
				}
				p.Files = []policy.File{
					{
						Filename: dockerfileName + ".rego",
						Data:     dt,
					},
				}
			}
		}
	}
	inp.policy = p

	target.FrontendAttrs["filename"] = dockerfileName

	for k, v := range inp.NamedContexts {
		caps["moby.buildkit.frontend.contexts+forward"] = struct{}{}
		if v.State != nil {
			target.FrontendAttrs["context:"+k] = "input:" + k
			if target.FrontendInputs == nil {
				target.FrontendInputs = make(map[string]llb.State)
			}
			target.FrontendInputs[k] = *v.State
			continue
		}

		if IsRemoteURL(v.Path) || strings.HasPrefix(v.Path, "docker-image://") || strings.HasPrefix(v.Path, "target:") {
			target.FrontendAttrs["context:"+k] = v.Path
			processGitURL(v.Path, "context:"+k, target, caps)
			continue
		}

		// handle OCI layout
		if localPath, ok := strings.CutPrefix(v.Path, "oci-layout://"); ok {
			localPath, dig, tag := parseOCILayoutPath(localPath)
			if dig == "" {
				dig, err = resolveDigest(localPath, tag)
				if err != nil {
					return nil, errors.Wrapf(err, "oci-layout reference %q could not be resolved", v.Path)
				}
			}
			store, err := local.NewStore(localPath)
			if err != nil {
				return nil, errors.Wrapf(err, "invalid store at %s", localPath)
			}
			storeName := identity.NewID()
			if target.OCIStores == nil {
				target.OCIStores = map[string]content.Store{}
			}
			target.OCIStores[storeName] = store

			target.FrontendAttrs["context:"+k] = "oci-layout://" + storeName + ":" + tag + "@" + dig
			continue
		}

		st, err := os.Stat(v.Path)
		if err != nil {
			return nil, errors.Wrapf(err, "failed to get build context %v", k)
		}
		if !st.IsDir() {
			return nil, errors.Wrapf(syscall.ENOTDIR, "failed to get build context path %v", v)
		}
		localName := k
		if k == "context" || k == "dockerfile" {
			localName = "_" + k // underscore to avoid collisions
		}
		if err := setLocalMount(localName, v.Path, target); err != nil {
			return nil, err
		}
		target.FrontendAttrs["context:"+k] = "local:" + localName
		sharedKey := v.Path
		if p, err := filepath.Abs(sharedKey); err == nil {
			sharedKey = filepath.Base(p)
		} else {
			sharedKey = filepath.Base(sharedKey)
		}
		target.FrontendAttrs["sharedkey:localdir:"+k] = sharedKey
	}

	release := func() {
		for _, dir := range toRemove {
			_ = os.RemoveAll(dir)
		}
	}

	if len(caps) > 0 {
		keys := slices.Collect(maps.Keys(caps))
		slices.Sort(keys)
		target.FrontendAttrs["frontend.caps"] = strings.Join(keys, ",")
	}

	inp.DockerfileMappingSrc = dockerfileSrcName
	inp.DockerfileMappingDst = dockerfileName
	return release, nil
}

func resolveDigest(localPath, tag string) (dig string, _ error) {
	idx := ociindex.NewStoreIndex(localPath)

	// lookup by name
	desc, err := idx.Get(tag)
	if err != nil {
		return "", err
	}
	if desc == nil {
		// lookup single
		desc, err = idx.GetSingle()
		if err != nil {
			return "", err
		}
	}
	if desc == nil {
		return "", errors.New("failed to resolve digest")
	}

	dig = string(desc.Digest)
	_, err = digest.Parse(dig)
	if err != nil {
		return "", errors.Wrapf(err, "invalid digest %s", dig)
	}

	return dig, nil
}

func setLocalMount(name, dir string, so *client.SolveOpt) error {
	lm, err := fsutil.NewFS(dir)
	if err != nil {
		return err
	}
	if so.LocalMounts == nil {
		so.LocalMounts = map[string]fsutil.FS{}
	}
	so.LocalMounts[name] = &fsMount{FS: lm, dir: dir}
	return nil
}

func createTempDockerfile(r io.Reader, multiReader *SyncMultiReader) (string, error) {
	dir, err := os.MkdirTemp("", "dockerfile")
	if err != nil {
		return "", err
	}
	f, err := os.Create(filepath.Join(dir, "Dockerfile"))
	if err != nil {
		return "", err
	}
	defer f.Close()

	if multiReader != nil {
		dt, err := io.ReadAll(r)
		if err != nil {
			return "", err
		}
		multiReader.Reset(dt)
		r = bytes.NewReader(dt)
	}

	if _, err := io.Copy(f, r); err != nil {
		return "", err
	}
	return dir, err
}

func processGitURL(url string, name string, target *client.SolveOpt, caps map[string]struct{}) error {
	gitRef, err := gitutil.ParseURL(url)
	if err != nil {
		return err
	}
	if len(gitRef.Query) == 0 {
		return nil
	}
	if !sendGitQueryAsInput() {
		capName := "moby.buildkit.frontend.gitquerystring"
		if name != "context" {
			capName += "+forward"
		}
		caps[capName] = struct{}{}
		return nil
	}

	var keepGitDir *bool
	if name == "context" {
		if v, ok := target.FrontendAttrs["build-arg:BUILDKIT_CONTEXT_KEEP_GIT_DIR"]; ok {
			if vv, err := strconv.ParseBool(v); err == nil {
				keepGitDir = &vv
			}
		}
	}

	st, ok, err := dockerui.DetectGitContext(url, keepGitDir)
	if err != nil {
		return err
	}
	if !ok {
		return nil
	}

	if target.FrontendInputs == nil {
		target.FrontendInputs = make(map[string]llb.State)
	}
	if name == "context" {
		target.FrontendInputs["context"] = *st
		delete(target.FrontendAttrs, "context")
		target.FrontendAttrs["input:context"] = url
	} else {
		inputName := "git_state_" + name
		target.FrontendInputs[inputName] = *st
		target.FrontendAttrs[name] = "input:" + inputName
		target.FrontendAttrs["input:"+name] = url
	}

	return nil
}

// handle https://github.com/moby/moby/pull/10858
func handleLowercaseDockerfile(dir, p string) string {
	if filepath.Base(p) != "Dockerfile" {
		return p
	}

	f, err := os.Open(filepath.Dir(filepath.Join(dir, p)))
	if err != nil {
		return p
	}

	names, err := f.Readdirnames(-1)
	if err != nil {
		return p
	}

	foundLowerCase := false
	for _, n := range names {
		if n == "Dockerfile" {
			return p
		}
		if n == "dockerfile" {
			foundLowerCase = true
		}
	}
	if foundLowerCase {
		return filepath.Join(filepath.Dir(p), "dockerfile")
	}
	return p
}

type fsMount struct {
	fsutil.FS
	dir string
}

var _ fsutil.FS = &fsMount{}

func CreateSSH(ssh []*buildflags.SSH) (session.Attachable, error) {
	configs := make([]sshprovider.AgentConfig, 0, len(ssh))
	for _, ssh := range ssh {
		cfg := sshprovider.AgentConfig{
			ID:    ssh.ID,
			Paths: slices.Clone(ssh.Paths),
		}
		configs = append(configs, cfg)
	}
	return sshprovider.NewSSHAgentProvider(configs)
}

func CreateSecrets(secrets []*buildflags.Secret) (session.Attachable, error) {
	fs := make([]secretsprovider.Source, 0, len(secrets))
	for _, secret := range secrets {
		fs = append(fs, secretsprovider.Source{
			ID:       secret.ID,
			FilePath: secret.FilePath,
			Env:      secret.Env,
		})
	}
	store, err := secretsprovider.NewStore(fs)
	if err != nil {
		return nil, err
	}
	return secretsprovider.NewSecretProvider(store), nil
}

func CreateExports(entries []*buildflags.ExportEntry) ([]client.ExportEntry, []string, error) {
	var outs []client.ExportEntry
	var localPaths []string
	if len(entries) == 0 {
		return nil, nil, nil
	}
	var stdoutUsed bool
	for _, entry := range entries {
		if entry.Type == "" {
			return nil, nil, errors.Errorf("type is required for output")
		}

		out := client.ExportEntry{
			Type:  entry.Type,
			Attrs: map[string]string{},
		}
		maps.Copy(out.Attrs, entry.Attrs)

		supportFile := false
		supportDir := false
		switch out.Type {
		case client.ExporterLocal:
			supportDir = true
		case client.ExporterTar:
			supportFile = true
		case client.ExporterOCI, client.ExporterDocker:
			tar, err := strconv.ParseBool(out.Attrs["tar"])
			if err != nil {
				tar = true
			}
			supportFile = tar
			supportDir = !tar
		case "registry":
			out.Type = client.ExporterImage
			out.Attrs["push"] = "true"
			// Skip unpacking when only pushing to registry (unless explicitly set)
			if _, ok := out.Attrs["unpack"]; !ok {
				out.Attrs["unpack"] = "false"
			}
		}

		if supportDir {
			if entry.Destination == "" {
				return nil, nil, errors.Errorf("dest is required for %s exporter", out.Type)
			}
			if entry.Destination == "-" {
				return nil, nil, errors.Errorf("dest cannot be stdout for %s exporter", out.Type)
			}

			fi, err := os.Stat(entry.Destination)
			if err != nil && !os.IsNotExist(err) {
				return nil, nil, errors.Wrapf(err, "invalid destination directory: %s", entry.Destination)
			}
			if err == nil && !fi.IsDir() {
				return nil, nil, errors.Errorf("destination directory %s is a file", entry.Destination)
			}
			out.OutputDir = entry.Destination
			localPaths = append(localPaths, entry.Destination)
		}
		if supportFile {
			if entry.Destination == "" && out.Type != client.ExporterDocker {
				entry.Destination = "-"
			}
			if entry.Destination == "-" {
				if stdoutUsed {
					return nil, nil, errors.Errorf("multiple outputs configured to write to stdout")
				}
				if _, err := console.ConsoleFromFile(os.Stdout); err == nil {
					return nil, nil, errors.Errorf("dest file is required for %s exporter. refusing to write to console", out.Type)
				}
				out.Output = wrapWriteCloser(os.Stdout)
				stdoutUsed = true
			} else if entry.Destination != "" {
				fi, err := os.Stat(entry.Destination)
				if err != nil && !os.IsNotExist(err) {
					return nil, nil, errors.Wrapf(err, "invalid destination file: %s", entry.Destination)
				}
				if err == nil && fi.IsDir() {
					return nil, nil, errors.Errorf("destination file %s is a directory", entry.Destination)
				}
				out.Output = wrapWriteCloserLazy(entry.Destination)
				localPaths = append(localPaths, entry.Destination)
			}
		}

		outs = append(outs, out)
	}
	return outs, localPaths, nil
}

func wrapWriteCloser(wc io.WriteCloser) func(map[string]string) (io.WriteCloser, error) {
	return func(map[string]string) (io.WriteCloser, error) {
		return wc, nil
	}
}

type lazyFileWriter struct {
	path string
	file *os.File
}

func (w *lazyFileWriter) Write(p []byte) (int, error) {
	if w.file == nil {
		if err := os.MkdirAll(filepath.Dir(w.path), 0o755); err != nil {
			return 0, err
		}
		f, err := os.Create(w.path)
		if err != nil {
			return 0, err
		}
		w.file = f
	}
	return w.file.Write(p)
}

func (w *lazyFileWriter) Close() error {
	if w.file != nil {
		return w.file.Close()
	}
	return nil
}

func wrapWriteCloserLazy(path string) func(map[string]string) (io.WriteCloser, error) {
	return func(map[string]string) (io.WriteCloser, error) {
		return &lazyFileWriter{path: path}, nil
	}
}

func CreateCaches(entries []*buildflags.CacheOptionsEntry) []client.CacheOptionsEntry {
	var outs []client.CacheOptionsEntry
	if len(entries) == 0 {
		return nil
	}

	for _, entry := range entries {
		out := client.CacheOptionsEntry{
			Type:  entry.Type,
			Attrs: map[string]string{},
		}
		maps.Copy(out.Attrs, entry.Attrs)
		addGithubToken(&out)
		addAwsCredentials(&out)
		if !isActive(&out) {
			continue
		}
		outs = append(outs, out)
	}
	return outs
}

func addGithubToken(ci *client.CacheOptionsEntry) {
	if ci.Type != "gha" {
		return
	}
	version, ok := ci.Attrs["version"]
	if !ok {
		// https://github.com/actions/toolkit/blob/2b08dc18f261b9fdd978b70279b85cbef81af8bc/packages/cache/src/internal/config.ts#L19
		if v, ok := os.LookupEnv("ACTIONS_CACHE_SERVICE_V2"); ok {
			if b, err := strconv.ParseBool(v); err == nil && b {
				version = "2"
			}
		}
	}
	if _, ok := ci.Attrs["token"]; !ok {
		if v, ok := os.LookupEnv("ACTIONS_RUNTIME_TOKEN"); ok {
			ci.Attrs["token"] = v
		}
	}
	if _, ok := ci.Attrs["url_v2"]; !ok && version == "2" {
		// https://github.com/actions/toolkit/blob/2b08dc18f261b9fdd978b70279b85cbef81af8bc/packages/cache/src/internal/config.ts#L34-L35
		if v, ok := os.LookupEnv("ACTIONS_RESULTS_URL"); ok {
			ci.Attrs["url_v2"] = v
		}
	}
	if _, ok := ci.Attrs["url"]; !ok {
		// https://github.com/actions/toolkit/blob/2b08dc18f261b9fdd978b70279b85cbef81af8bc/packages/cache/src/internal/config.ts#L28-L33
		if v, ok := os.LookupEnv("ACTIONS_CACHE_URL"); ok {
			ci.Attrs["url"] = v
		} else if v, ok := os.LookupEnv("ACTIONS_RESULTS_URL"); ok {
			ci.Attrs["url"] = v
		}
	}
}

func addAwsCredentials(ci *client.CacheOptionsEntry) {
	if ci.Type != "s3" {
		return
	}
	_, okAccessKeyID := ci.Attrs["access_key_id"]
	_, okSecretAccessKey := ci.Attrs["secret_access_key"]
	// If the user provides access_key_id, secret_access_key, do not override the session token.
	if okAccessKeyID && okSecretAccessKey {
		return
	}
	ctx := context.TODO()
	awsConfig, err := awsconfig.LoadDefaultConfig(ctx)
	if err != nil {
		return
	}
	credentials, err := awsConfig.Credentials.Retrieve(ctx)
	if err != nil {
		return
	}
	if !okAccessKeyID && credentials.AccessKeyID != "" {
		ci.Attrs["access_key_id"] = credentials.AccessKeyID
	}
	if !okSecretAccessKey && credentials.SecretAccessKey != "" {
		ci.Attrs["secret_access_key"] = credentials.SecretAccessKey
	}
	if _, ok := ci.Attrs["session_token"]; !ok && credentials.SessionToken != "" {
		ci.Attrs["session_token"] = credentials.SessionToken
	}
}

func isActive(ce *client.CacheOptionsEntry) bool {
	// Always active if not gha.
	if ce.Type != "gha" {
		return true
	}
	return ce.Attrs["token"] != "" && (ce.Attrs["url"] != "" || ce.Attrs["url_v2"] != "")
}

// parseOCILayoutPath handles the oci-layout url accepted by buildx.
func parseOCILayoutPath(s string) (localPath, dgst, tag string) {
	localPath = s

	// Look for the digest reference. There might be multiple @ symbols
	// in the path and the @ symbol may be part of the path or part of
	// the digest. If we find the @ symbol, verify that it's a valid
	// digest reference instead of just assuming it is because it
	// might be part of the file path.
	if i := strings.LastIndex(localPath, "@"); i >= 0 {
		after := localPath[i+1:]
		if reference.DigestRegexp.MatchString(after) {
			localPath, dgst = localPath[:i], after
		}
	}

	// Do the same with the tag. This isn't as necessary since colons
	// aren't valid as file paths on Linux/Unix systems, but they are valid
	// on Windows systems so we might as well just be safe.
	if i := strings.LastIndex(localPath, ":"); i >= 0 {
		after := localPath[i+1:]
		if reference.TagRegexp.MatchString(after) {
			localPath, tag = localPath[:i], after
		}
	}

	if tag == "" {
		tag = "latest"
	}
	return
}

func defaultPlatform(bopts gateway.BuildOpts) *ocispecs.Platform {
	pl := bopts.Workers[0].Platforms
	if len(pl) == 0 {
		return nil
	}
	p := platforms.Normalize(pl[0])
	return &p
}