feat: Add multiarch support to csi-snapshot-metadata Dockerfile

[kaovilai]

Summary

This PR refactors the Dockerfile to enable multiarch support and build the csi-snapshot-metadata binary from source in the builder stage.

Changes

1. Multiarch grpc_health_probe support

• Add TARGETARCH build argument
• Use grpc_health_probe-linux-${TARGETARCH} instead of hardcoded amd64
• Add --platform=$BUILDPLATFORM to builder stage for cross-compilation

2. Build csi-snapshot-metadata in builder stage

Dockerfile changes:

• Use golang:1.24-alpine as builder base (was alpine)
• Add TARGETOS and LDFLAGS build arguments
• Copy Go source files (go.mod, go.sum, cmd/, pkg/, client/, vendor/)
• Build binary in builder with cross-compilation support
• Copy built binary from builder (was copying from host filesystem)
• Remove obsolete binary ARG

Makefile changes (release-tools/build.make):

• Replace --build-arg binary with --build-arg LDFLAGS
• Remove build-% dependency from push-multiarch-% target
  (Docker now builds from source, eliminating duplicate compilation)
• Fix manifest error detection to handle both error formats:
  • "manifest for ... not found" (docker.io)
  • "manifest unknown" (ghcr.io, quay.io)

Benefits

• ✅ Self-contained builds (no external Makefile dependency for Docker)
• ✅ True cross-compilation via Docker buildx
• ✅ Consistent approach (both binaries prepared in builder stage)
• ✅ Easier for contributors (just docker build or podman build)
• ✅ Supports linux/amd64 and linux/arm64 platforms

Testing

Tested with multiarch build to ghcr.io:

make push-multiarch-csi-snapshot-metadata \
  REGISTRY_NAME=ghcr.io/kaovilai \
  PULL_BASE_REF=test-20251119-014146 \
  BUILD_PLATFORMS="linux amd64 amd64; linux arm64 arm64"

Verified multiarch manifest contains both architectures:

• linux/amd64: sha256:38a12212d86d92c20fb5762c63846bf8290790ed048b2622d9550cac9334416e
• linux/arm64: sha256:e01b090c4db6124e802e73ee034632bb98cdc3b7c6dc418cb5c03e8cf785418a

🤖 Generated with Claude Code

Co-Authored-By: Claude [email protected]

---

What type of PR is this?
/kind feature

What this PR does / why we need it:
Enables building multiarch container images (amd64, arm64) with the csi-snapshot-metadata binary built from source in the Dockerfile builder stage, making the build process self-contained and easier for contributors.

Which issue(s) this PR fixes:
N/A

Special notes for your reviewer:

• The Dockerfile now builds from source instead of relying on pre-built binaries from the Makefile
• The Makefile changes are backward compatible - make build-csi-snapshot-metadata still works for local development
• Tested successfully with both docker and podman

Does this PR introduce a user-facing change?:

Container images now support multiple architectures (amd64, arm64) via multiarch manifests

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: kaovilai
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[k8s-ci-robot]

Hi @kaovilai. Thanks for your PR.

I'm waiting for a github.com member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[kaovilai]

CSI Snapshot Metadata Container Readiness Probe Fails on ARM64

Problem:

• The csi-snapshot-metadata container's readiness probe fails with "Exec format error"
• The grpc_health_probe binary in the container image is built for AMD64, not ARM64
• This prevents the container from becoming "Ready" (8/9 containers ready)

Impact: Low - Container is functional despite readiness probe failure; CBT APIs work correctly

Evidence:

$ kubectl describe pod csi-hostpathplugin-0 -n default
Warning  Unhealthy  Readiness probe failed: exec: Exec format error

Root Cause:
Upstream CSI driver images (gcr.io/k8s-staging-sig-storage/csi-snapshot-metadata:canary) are primarily built for AMD64

[Rakshith-R]

/ok-to-test

[k8s-ci-robot]

@kaovilai: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-kubernetes-csi-external-snapshot-metadata-unit	0e03558	link	true	/test pull-kubernetes-csi-external-snapshot-metadata-unit

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository. I understand the commands that are listed here.

[jsafrane]

The released snapshot-metadata sidecar images are already multiarch, built by Makefile in this repository. What exactly are you trying to achieve?

$ docker manifest inspect registry.k8s.io/sig-storage/csi-snapshot-metadata:v0.2.0
{
   "schemaVersion": 2,
   "mediaType": "application/vnd.docker.distribution.manifest.list.v2+json",
   "manifests": [
      {
         "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
         "size": 3235,
         "digest": "sha256:08eeefe99d22c9893c5bf694d6c719a7bc08601fd55b09bbe86fde72de8a41b7",
         "platform": {
            "architecture": "amd64",
            "os": "linux"
         }
      },
      {
         "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
         "size": 3235,
         "digest": "sha256:96df09d94f4513b513c83d52bd65f3fade8c269fd7529fe47548b4fcd47d6ce4",
         "platform": {
            "architecture": "arm",
            "os": "linux",
            "variant": "v7"
         }
      },
      {
         "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
         "size": 3235,
         "digest": "sha256:cdee9fdebb7e69446014537e63ec1485ad111f3d344d6a5a54b356fc4711eb3c",
         "platform": {
            "architecture": "arm",
            "os": "linux",
            "variant": "v7"
         }
      },
      {
         "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
         "size": 3235,
         "digest": "sha256:ebbc2cb3aff245d7450f986389bcebd48726035d36f14736a88c26c68cb89d8d",
         "platform": {
            "architecture": "arm64",
            "os": "linux"
         }
      },
      {
         "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
         "size": 3235,
         "digest": "sha256:a935233cad5e844cdaa8b54e9a2bb80f0c3c6b9cfc5195612f5d790228c35774",
         "platform": {
            "architecture": "ppc64le",
            "os": "linux"
         }
      },
      {
         "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
         "size": 3235,
         "digest": "sha256:f06da751ce627bc1a0f300b0ee4e524cc5e86ca4036921a4b68396785e2989d9",
         "platform": {
            "architecture": "s390x",
            "os": "linux"
         }
      }
   ]
}

[jsafrane]

Upstream CSI driver images (gcr.io/k8s-staging-sig-storage/csi-snapshot-metadata:canary) are primarily built for AMD64

No, csi-snapshot-metadata:canary is available as s390x, ppc64le, arm64, arm and amd64