Inherit arguments between stages

imagebuildah/executor.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"maps"
 	"os"
 	"sort"
 	"strconv"
@@ -164,6 +165,7 @@ type Executor struct {
 	compatVolumes                           types.OptionalBool
 	compatScratchConfig                     types.OptionalBool
 	noPivotRoot                             bool
+	argResult                               map[string]map[string]string
 }
 
 type imageTypeAndHistoryAndDiffIDs struct {
@@ -324,6 +326,7 @@ func newExecutor(logger *logrus.Logger, logPrefix string, store storage.Store, o
 		compatVolumes:                           options.CompatVolumes,
 		compatScratchConfig:                     options.CompatScratchConfig,
 		noPivotRoot:                             options.NoPivotRoot,
+		argResult:                               make(map[string]map[string]string),
 	}
 	if exec.err == nil {
 		exec.err = os.Stderr
@@ -413,7 +416,7 @@ func (b *Executor) resolveNameToImageRef(output string) (types.ImageReference, e
 // that the specified stage has finished.  If there is no stage defined by that
 // name, then it will return (false, nil).  If there is a stage defined by that
 // name, it will return true along with any error it encounters.
-func (b *Executor) waitForStage(ctx context.Context, name string, stages imagebuilder.Stages) (bool, error) {
+func (b *Executor) waitForStage(ctx context.Context, name string, stages imagebuilder.Stages) (bool, map[string]string, error) {
 	found := false
 	for _, otherStage := range stages {
 		if otherStage.Name == name || strconv.Itoa(otherStage.Position) == name {
@@ -422,32 +425,41 @@ func (b *Executor) waitForStage(ctx context.Context, name string, stages imagebu
 		}
 	}
 	if !found {
-		return false, nil
+		return false, nil, nil
 	}
 	for {
 		if b.lastError != nil {
-			return true, b.lastError
+			return true, nil, b.lastError
 		}
 
 		b.stagesLock.Lock()
 		terminationError, terminated := b.terminatedStage[name]
+		args := b.argResult[name]
 		b.stagesLock.Unlock()
 
 		if terminationError != nil {
-			return false, terminationError
+			return false, nil, terminationError
 		}
 		if terminated {
-			return true, nil
+			return true, nil, nil
 		}
 
 		b.stagesSemaphore.Release(1)
 		time.Sleep(time.Millisecond * 10)
 		if err := b.stagesSemaphore.Acquire(ctx, 1); err != nil {
-			return true, fmt.Errorf("reacquiring job semaphore: %w", err)
+			return true, args, fmt.Errorf("reacquiring job semaphore: %w", err)
 		}
 	}
 }
 
+// freezeArgs stores a copy of the argument map for further use in dependent stages
+func (b *Executor) freezeArgs(name string, args map[string]string) {
+	copiedArgs := maps.Clone(args)
+	b.stagesLock.Lock()
+	b.argResult[name] = copiedArgs
+	b.stagesLock.Unlock()
+}
+
 // getImageTypeAndHistoryAndDiffIDs returns the manifest type, history, and diff IDs list of imageID.
 func (b *Executor) getImageTypeAndHistoryAndDiffIDs(ctx context.Context, imageID string) (string, []v1.History, []digest.Digest, error) {
 	b.imageInfoLock.Lock()

imagebuildah/stage_executor.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"maps"
 	"os"
 	"path"
 	"path/filepath"
@@ -512,7 +513,7 @@ func (s *StageExecutor) performCopy(excludes []string, copies ...imagebuilder.Co
 				}
 			}
 			if additionalBuildContext == nil {
-				if isStage, err := s.executor.waitForStage(s.ctx, from, s.stages[:s.index]); isStage && err != nil {
+				if isStage, _, err := s.executor.waitForStage(s.ctx, from, s.stages[:s.index]); isStage && err != nil {
 					return err
 				}
 				if other, ok := s.executor.stages[from]; ok && other.index < s.index {
@@ -677,7 +678,7 @@ func (s *StageExecutor) runStageMountPoints(mountList []string) (map[string]inte
 					// If the source's name corresponds to the
 					// result of an earlier stage, wait for that
 					// stage to finish being built.
-					if isStage, err := s.executor.waitForStage(s.ctx, from, s.stages[:s.index]); isStage && err != nil {
+					if isStage, _, err := s.executor.waitForStage(s.ctx, from, s.stages[:s.index]); isStage && err != nil {
 						return nil, err
 					}
 					// If the source's name is a stage, return a
@@ -1149,9 +1150,15 @@ func (s *StageExecutor) Execute(ctx context.Context, base string) (imgID string,
 	// If not, then go on assuming that it's just a regular image that's
 	// either in local storage, or one that we have to pull from a
 	// registry, subject to the passed-in pull policy.
-	if isStage, err := s.executor.waitForStage(ctx, base, s.stages[:s.index]); isStage && err != nil {
+	// This helper will also return the final resolved argument list from
+	// the parent stage, if available.
+	isStage, parentArgs, err := s.executor.waitForStage(ctx, base, s.stages[:s.index])
+	if isStage && err != nil {
 		return "", nil, false, err
 	}
+	// Update the start args with those from the parent stage
+	maps.Copy(ib.Args, parentArgs)
+
 	pullPolicy := s.executor.pullPolicy
 	s.executor.stagesLock.Lock()
 	var preserveBaseImageAnnotationsAtStageStart bool
@@ -1369,7 +1376,7 @@ func (s *StageExecutor) Execute(ctx context.Context, base string) (imgID string,
 				// If the source's name corresponds to the
 				// result of an earlier stage, wait for that
 				// stage to finish being built.
-				if isStage, err := s.executor.waitForStage(ctx, from, s.stages[:s.index]); isStage && err != nil {
+				if isStage, _, err := s.executor.waitForStage(ctx, from, s.stages[:s.index]); isStage && err != nil {
 					return "", nil, false, err
 				}
 				if otherStage, ok := s.executor.stages[from]; ok && otherStage.index < s.index {
@@ -1742,6 +1749,9 @@ func (s *StageExecutor) Execute(ctx context.Context, base string) (imgID string,
 		}
 	}
 
+	// store the final argument map for further use
+	s.executor.freezeArgs(s.name, ib.Args)
+
 	return imgID, ref, onlyBaseImage, nil
 }
 

tests/conformance/conformance_test.go

@@ -3451,6 +3451,17 @@ var internalTestCases = []testCase{
 		dockerUseBuildKit: true,
 		buildArgs:         map[string]string{"SOURCE": "e/**/**/*sub/*.txt"},
 	},
+
+	{
+		name:              "argument inheritance",
+		dockerUseBuildKit: true,
+		dockerfileContents: strings.Join([]string{
+			"FROM mirror.gcr.io/busybox AS base",
+			"ARG NAME=\"joe\"",
+			"FROM base AS build",
+			"RUN echo \"hello $NAME!\" > /hello.txt",
+		}, "\n"),
+	},
 }
 
 func TestCommit(t *testing.T) {