feat(aws): AMI architecture detection and cross-validation

[ArangoGutierrez]

Summary

• Add describeImageArch helper to query AMI architecture from EC2
• Update resolveImageForNode to return architecture for explicit ImageId (was skipping all arch detection)
• Add getInstanceTypeArch to query instance type supported architectures
• Cross-validate AMI arch against instance type arch in DryRun()

Catches arm64 AMI + x86_64 instance type mismatches with a clear error message instead of cryptic boot failures.

Test plan

• Unit tests for describeImageArch with mock EC2 client
• Unit tests for getInstanceTypeArch with mock EC2 client
• Unit test for DryRun() returning error on arch mismatch
• go test ./pkg/provider/aws/... -v passes
• CI validation pending

[Copilot]

Pull request overview

This PR adds AMI architecture detection and cross-validation to prevent architecture mismatches between AMIs and instance types. Previously, when an explicit AMI ID was provided, architecture detection was skipped, leading to cryptic boot failures when arm64 AMIs were used with x86_64 instance types (or vice versa). The PR implements three new helper functions to query architecture information from EC2 APIs and integrates a validation check in the DryRun() method to catch these mismatches early with clear error messages.

Changes:

• Added describeImageArch() to query AMI architecture from EC2 DescribeImages API
• Added getInstanceTypeArch() to query supported architectures from EC2 DescribeInstanceTypes API
• Added normalizeArchToEC2() to convert architecture aliases (amd64/aarch64) to EC2 canonical forms (x86_64/arm64)
• Enhanced resolveImageForNode() to detect and return architecture for explicit ImageIds
• Added architecture cross-validation in DryRun() to catch AMI/instance type mismatches
• Updated all mock EC2 responses to include ProcessorInfo with architecture data

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pkg/provider/aws/image.go	Core implementation: added three new helper functions for architecture detection/normalization, updated resolveImageForNode to query architecture for explicit AMIs, updated ResolvedImage struct to include architecture, added architecture normalization in resolveOSToAMI and setLegacyAMI
pkg/provider/aws/dryrun.go	Added architecture compatibility validation that cross-checks AMI architecture against instance type supported architectures and returns a clear error on mismatch
pkg/provider/aws/image_test.go	Comprehensive unit tests for new functions including describeImageArch, getInstanceTypeArch, and DryRun scenarios for both architecture match and mismatch cases, plus assertion that architecture is always populated
pkg/provider/aws/mock_ec2_test.go	Updated default mock responses for DescribeInstanceTypes to include ProcessorInfo with supported architectures
pkg/provider/aws/aws_test.go	Updated mock responses in existing tests to include ProcessorInfo architecture data
pkg/provider/aws/aws_ginkgo_test.go	Updated mock responses in Ginkgo tests to include ProcessorInfo architecture data

[coveralls]

Pull Request Test Coverage Report for Build 22021789809

Details

• 74 of 82 (90.24%) changed or added relevant lines in 2 files are covered.
• 9 unchanged lines in 1 file lost coverage.
• Overall coverage remained the same at 47.856%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/provider/aws/dryrun.go	18	21	85.71%
pkg/provider/aws/image.go	56	61	91.8%

Files with Coverage Reduction	New Missed Lines	%
pkg/provider/aws/image.go	9	83.72%

Totals
Change from base Build 21999063489:	0.0%
Covered Lines:	2567
Relevant Lines:	5364

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💛 - Coveralls

[ArangoGutierrez]

Closing as superseded. The equivalent fixes were already merged into main via PRs #661-664:

• feat(aws): AMI architecture detection and cross-validation #664: feat(aws): AMI architecture detection and cross-validation
• fix(aws): propagate architecture in cluster mode #661: fix(aws): propagate architecture in cluster mode
• fix(templates): dynamic CUDA repo arch for arm64 support #662: fix(templates): use runtime arch for NVIDIA CUDA repository URL
• fix(templates): runtime Kubernetes arch detection for arm64 #663: fix(templates): detect Kubernetes arch at runtime instead of defaulting to amd64

Additionally, these fixes address downstream provisioning issues but do not resolve the actual EC2 RunInstances failure (Unsupported: The requested configuration is currently not supported) reported in https://github.com/NVIDIA/gpu-driver-container/actions/runs/22012665274/job/63611032634. The root cause is missing architecture inference from instance type — when image.architecture is unset, holodeck defaults to x86_64 regardless of the instance type. A new PR will address this.