Feature Request: ARM64 (aarch64) Container Image Support

[holyshipt]

Feature Request: ARM64 (aarch64) Container Image Support

Problem Statement

The current gcr.io/trafficdirector-prod/td-grpc-bootstrap container images (versions 0.16.0, 0.17.0, 0.18.0) only support linux/amd64 architecture. This prevents users from running Traffic Director-enabled workloads on ARM64 nodes, such as:

• GKE Autopilot with Arm-based workloads
• GKE Standard clusters with C4A (Axion) or N4A (Ampere Altra) machine types
• Cost optimization initiatives leveraging ARM64's ~50% lower compute costs

Current Behavior

When attempting to run the init container on ARM64 nodes:

exec /td-grpc-bootstrap: exec format error

Example deployment configuration:

initContainers:
- name: grpc-td-init
  image: gcr.io/trafficdirector-prod/td-grpc-bootstrap:0.18.0
  # Fails on arm64 nodes with exec format error

Expected Behavior

The td-grpc-bootstrap image should be published as a multi-architecture image supporting both:

• linux/amd64
• linux/arm64

This would allow Kubernetes to automatically pull the correct architecture based on the node type.

Use Case

We are migrating GKE workloads to ARM64 (C4A/N4A) instances for cost reduction. Our services use Traffic Director for service mesh capabilities, but the migration is blocked because the bootstrap init container cannot run on ARM64 nodes.

Proposed Solution

1. Build td-grpc-bootstrap for both amd64 and arm64 architectures
2. Publish as a multi-arch Docker manifest
3. Ensure future releases include both architectures

Additional Context

• GKE machine types using ARM64: C4A (Axion), N4A (Ampere Altra)
• Many GCP customers are adopting ARM64 for cost savings
• Other GCP tools already support multi-arch (e.g., many Cloud SDK containers)

Workaround Attempts

Currently, there is no viable workaround besides:

• Staying on x86 nodes (missing out on cost savings)
• Not using Traffic Director (requires architecture changes)

Would appreciate any timeline or roadmap information for ARM64 support.

---

Environment:

• GKE Version: 1.33+
• td-grpc-bootstrap versions tested: 0.16.0, 0.17.0, 0.18.0
• Node architecture: arm64 (C4A, N4A)

[ejona86]

The release artifact build is being reworked. This will need to wait for that to complete, so that we don't add support only to remove it again. We wouldn't want to block the new build pipeline on ARM support.

You're welcome to open a feature request with support to help prioritize.

[holyshipt]

Thank you @ejona86, what's the ETA you can share for new release build process? We had workaround but could benefit from official support.

[ejona86]

@easwars, do you have an idea of when we might be able to start looking at this? Maybe we could start on this before your work is complete?

[davidbellemare]

Any update on this? We would like to use official container instead of custom build.

[easwars]

@davidbellemare : Sorry, the work on the release artifact pipeline has taken longer than most expected, mainly because it keeps going down in the priority list. From what I can see, I don't think I will be able to get it ready before the end of this quarter. So, if you are really blocked, please do sent a PR to add ARM support. Thanks again.