test(integration): add boot image stream resolution tests for AWS

Add TestBootImageStreamResolution with AWS subtests covering the
end-to-end flow from HostedCluster + NodePool + ReleaseImage through
ResolveAWSAMI. Tests multi-stream payload resolution, user AMI
override precedence, legacy 4.x backward compatibility, unsupported
architecture and missing region error paths. Structured with
t.Run("AWS", ...) so future providers (GCP, KubeVirt, etc.) are
added as new subtests in CNTRLPLANE-3027.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Juan Manuel Parrilla Madrid <jparrill@redhat.com>

Author: jparrill

test/integration/osstreams/osstreams_test.go

@@ -8,9 +8,13 @@ import (
 	"github.com/blang/semver"
 	. "github.com/onsi/gomega"
 
+	hyperv1 "github.com/openshift/hypershift/api/hypershift/v1beta1"
 	"github.com/openshift/hypershift/hypershift-operator/controllers/nodepool"
 	"github.com/openshift/hypershift/support/releaseinfo"
 	"github.com/openshift/hypershift/support/releaseinfo/fixtures"
+
+	imagev1 "github.com/openshift/api/image/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
 func TestOSStreamsEndToEnd(t *testing.T) {
@@ -197,3 +201,120 @@ func TestOSStreamsLegacyPayloadBackwardCompat(t *testing.T) {
 		g.Expect(err.Error()).To(ContainSubstring("no multi-stream metadata"))
 	})
 }
+
+// TestBootImageStreamResolution tests platform-specific boot image resolvers
+// with multi-stream metadata. Each platform has its own subtest block.
+// Adding a provider = adding a new t.Run block with platform-specific cases.
+func TestBootImageStreamResolution(t *testing.T) {
+	g := NewWithT(t)
+
+	// Multi-stream payload (OCP 5.0+)
+	defaultStream5, osStreams5, err := releaseinfo.DeserializeImageMetadata(fixtures.CoreOSBootImagesYAML_5_0)
+	g.Expect(err).ToNot(HaveOccurred())
+	multiStreamRelease := &releaseinfo.ReleaseImage{
+		ImageStream:    &imagev1.ImageStream{ObjectMeta: metav1.ObjectMeta{Name: "5.0.0"}},
+		StreamMetadata: defaultStream5,
+		OSStreams:       osStreams5,
+	}
+
+	// Legacy single-stream payload (OCP 4.10)
+	defaultStream4, _, err := releaseinfo.DeserializeImageMetadata(fixtures.CoreOSBootImagesYAML_4_10)
+	g.Expect(err).ToNot(HaveOccurred())
+	legacyRelease := &releaseinfo.ReleaseImage{
+		ImageStream:    &imagev1.ImageStream{ObjectMeta: metav1.ObjectMeta{Name: "4.10.0"}},
+		StreamMetadata: defaultStream4,
+	}
+
+	t.Run("AWS", func(t *testing.T) {
+		testCases := []struct {
+			name          string
+			region        string
+			arch          string
+			amiOverride   string
+			releaseImage  *releaseinfo.ReleaseImage
+			expectedAMI   string
+			expectedErr   bool
+		}{
+			// --- Happy paths ---
+			{
+				name:         "When resolving amd64 AMI with multi-stream payload it should return default stream AMI",
+				region:       "us-east-1",
+				arch:         "amd64",
+				releaseImage: multiStreamRelease,
+				expectedAMI:  "ami-06a6b025350ff1e23",
+			},
+			{
+				name:         "When resolving arm64 AMI with multi-stream payload it should return default stream AMI",
+				region:       "us-east-1",
+				arch:         "arm64",
+				releaseImage: multiStreamRelease,
+				expectedAMI:  "ami-0e73a95fb409d8abd",
+			},
+			{
+				name:         "When NodePool has explicit AMI override it should return the override",
+				region:       "us-east-1",
+				arch:         "amd64",
+				amiOverride:  "ami-user-custom-override",
+				releaseImage: multiStreamRelease,
+				expectedAMI:  "ami-user-custom-override",
+			},
+			{
+				name:         "When using legacy 4.x payload it should resolve from single-stream metadata",
+				region:       "us-east-1",
+				arch:         "amd64",
+				releaseImage: legacyRelease,
+				expectedAMI:  "ami-0713d9bcf78401cd1",
+			},
+			// --- Sad paths ---
+			{
+				name:         "When region has no AMI it should return error",
+				region:       "xx-nonexistent-1",
+				arch:         "amd64",
+				releaseImage: multiStreamRelease,
+				expectedErr:  true,
+			},
+			{
+				name:         "When architecture has no ArchAliases mapping it should return error",
+				region:       "us-east-1",
+				arch:         "ppc64le",
+				releaseImage: multiStreamRelease,
+				expectedErr:  true,
+			},
+			{
+				name:         "When stream metadata is nil it should return error",
+				region:       "us-east-1",
+				arch:         "amd64",
+				releaseImage: &releaseinfo.ReleaseImage{ImageStream: &imagev1.ImageStream{ObjectMeta: metav1.ObjectMeta{Name: "5.0.0"}}},
+				expectedErr:  true,
+			},
+		}
+
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				g := NewWithT(t)
+
+				hc := &hyperv1.HostedCluster{
+					Spec: hyperv1.HostedClusterSpec{
+						Platform: hyperv1.PlatformSpec{
+							AWS: &hyperv1.AWSPlatformSpec{Region: tc.region},
+						},
+					},
+				}
+				np := &hyperv1.NodePool{
+					Spec: hyperv1.NodePoolSpec{
+						Arch:     tc.arch,
+						Platform: hyperv1.NodePoolPlatform{AWS: &hyperv1.AWSNodePoolPlatform{AMI: tc.amiOverride}},
+					},
+				}
+
+				ami, err := nodepool.ResolveAWSAMI(hc, np, tc.releaseImage)
+				if tc.expectedErr {
+					g.Expect(err).To(HaveOccurred())
+				} else {
+					g.Expect(err).ToNot(HaveOccurred())
+					g.Expect(ami).To(Equal(tc.expectedAMI))
+				}
+			})
+		}
+	})
+}