build --all-platforms: skip some base "image" platforms

imagebuildah/build.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	gotypes "go/types"
 	"io"
 	"net/http"
 	"os"
@@ -36,6 +37,7 @@ import (
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/openshift/imagebuilder"
 	"github.com/sirupsen/logrus"
+	"golang.org/x/exp/slices"
 	"golang.org/x/sync/semaphore"
 )
 
@@ -493,6 +495,26 @@ func preprocessContainerfileContents(logger *logrus.Logger, containerfile string
 	return &stdoutBuffer, nil
 }
 
+// platformIsUnknown checks if the platform value indicates that the
+// corresponding index entry is suitable for use as a base image
+func platformIsAcceptable(platform *v1.Platform, logger *logrus.Logger) bool {
+	if platform == nil {
+		logger.Trace("rejecting potential base image with no platform information")
+		return false
+	}
+	if gotypes.SizesFor("gc", platform.Architecture) == nil {
+		// the compiler's never heard of this
+		logger.Tracef("rejecting potential base image architecture %q for which Go has no knowledge of how to do unsafe code", platform.Architecture)
+		return false
+	}
+	if slices.Contains([]string{"", "unknown"}, platform.OS) {
+		// we're hard-wired to reject images with these values
+		logger.Tracef("rejecting potential base image for which the OS value is always-rejected value %q", platform.OS)
+		return false
+	}
+	return true
+}
+
 // platformsForBaseImages resolves the names of base images from the
 // dockerfiles, and if they are all valid references to manifest lists, returns
 // the list of platforms that are supported by all of the base images.
@@ -570,7 +592,10 @@ func platformsForBaseImages(ctx context.Context, logger *logrus.Logger, dockerfi
 		if baseImageIndex == 0 {
 			// populate the list with the first image's normalized platforms
 			for _, instance := range index.Manifests {
-				if instance.Platform == nil {
+				if !platformIsAcceptable(instance.Platform, logger) {
+					continue
+				}
+				if instance.ArtifactType != "" {
 					continue
 				}
 				platform := internalUtil.NormalizePlatform(*instance.Platform)
@@ -581,7 +606,10 @@ func platformsForBaseImages(ctx context.Context, logger *logrus.Logger, dockerfi
 			// prune the list of any normalized platforms this base image doesn't support
 			imagePlatforms := make(map[string]struct{})
 			for _, instance := range index.Manifests {
-				if instance.Platform == nil {
+				if !platformIsAcceptable(instance.Platform, logger) {
+					continue
+				}
+				if instance.ArtifactType != "" {
 					continue
 				}
 				platform := internalUtil.NormalizePlatform(*instance.Platform)

tests/bud/from-base/Containerfile

@@ -0,0 +1,2 @@
+FROM base
+ADD . .

tests/lists.bats

@@ -318,3 +318,30 @@ IMAGE_LIST_S390X_INSTANCE_DIGEST=sha256:882a20ee0df7399a445285361d38b711c299ca09
     # since manifest does not exist in local storage this should exit with `1`
     run_buildah 1 manifest exists test2
 }
+
+@test "manifest-skip-some-base-images-with-all-platforms" {
+    start_registry
+    run_buildah manifest create localhost:"${REGISTRY_PORT}"/base
+    run_buildah manifest add --all localhost:"${REGISTRY_PORT}"/base ${IMAGE_LIST}
+    # get a count of how many "real" base images there are
+    run_buildah manifest inspect localhost:"${REGISTRY_PORT}"/base
+    nbaseplatforms=$(grep '"platform"' <<< "$output" | wc -l)
+    echo $nbaseplatforms base platforms
+    # add some trash that we expect to skip in a --all-platforms build
+    run_buildah build --manifest localhost:"${REGISTRY_PORT}"/base --platform unknown/unknown --no-cache -f $BUDFILES/from-scratch/Containerfile2 $BUDFILES/from-scratch
+    run_buildah build --manifest localhost:"${REGISTRY_PORT}"/base --platform linux/unknown --no-cache -f $BUDFILES/from-scratch/Containerfile2 $BUDFILES/from-scratch
+    run_buildah build --manifest localhost:"${REGISTRY_PORT}"/base --platform unknown/amd64p32 --no-cache -f $BUDFILES/from-scratch/Containerfile2 $BUDFILES/from-scratch
+    # add a known combination of OS/arch that we can be pretty sure wasn't already there
+    run_buildah build --manifest localhost:"${REGISTRY_PORT}"/base --platform linux/amd64p32 --no-cache -f $BUDFILES/from-scratch/Containerfile2 $BUDFILES/from-scratch
+    # push the list to the local registry and clean up our local copy
+    run_buildah manifest push --tls-verify=false --creds testuser:testpassword --all localhost:"${REGISTRY_PORT}"/base
+    run_buildah rmi localhost:"${REGISTRY_PORT}"/base
+    # build a new list based on the valid base images in the list we just pushed
+    run_buildah build --tls-verify=false --creds testuser:testpassword --manifest derived --all-platforms --from localhost:"${REGISTRY_PORT}"/base $BUDFILES/from-base
+    run_buildah manifest inspect derived
+    nderivedplatforms=$(grep '"platform"' <<< "$output" | wc -l)
+    echo $nderivedplatforms derived platforms
+    nexpectedderivedplatforms=$((nbaseplatforms+1))
+    echo expected $nexpectedderivedplatforms derived platforms
+    [[ $nderivedplatforms -eq $nexpectedderivedplatforms ]]
+}