Add armhf support for the forthcoming K8s release

[mattmoor]

cc @hasheddan

This still needs the cloudbuild changes, which I'll stage and test ~now.

[mattmoor]

Alright, I just did a GCB run with the changes I'm about to push, and this is one of the resulting images:

crane manifest gcr.io/mattmoor-knative/static:latest | jq .
{
  "schemaVersion": 2,
  "mediaType": "application/vnd.docker.distribution.manifest.list.v2+json",
  "manifests": [
    {
      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
      "size": 426,
      "digest": "sha256:a7fbf4bc518870042021d9fff54b486da3c3182f880b52f91439d63895ec8423",
      "platform": {
        "architecture": "amd64",
        "os": "linux"
      }
    },
    {
      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
      "size": 426,
      "digest": "sha256:0fb03485bed51c9ee7a7c7362da40c23e202ec75f8660a5fa3b6164849866dc5",
      "platform": {
        "architecture": "arm",
        "os": "linux"
      }
    },
    {
      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
      "size": 426,
      "digest": "sha256:fcee51c84824bea83e2692cd1fb2a5d26038371581b2bef80a167a374a01f35e",
      "platform": {
        "architecture": "arm64",
        "os": "linux"
      }
    },
    {
      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
      "size": 426,
      "digest": "sha256:6284b3a8dbdb0df27072217be18115224c392df29d2cb79c5c3cbef72a33e649",
      "platform": {
        "architecture": "ppc64le",
        "os": "linux"
      }
    },
    {
      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
      "size": 426,
      "digest": "sha256:b0dc5adcc32d2b00f871ea0d4badd0d7bd884255a1b3f47b199fd40ad03a7f07",
      "platform": {
        "architecture": "s390x",
        "os": "linux"
      }
    }
  ]
}

[chanseokoh]

There are build failures. Seems related?

[mattmoor]

@chanseokoh I must've messed something up in my second commit Friday, I'll TAL now.

[mattmoor]

Looks like just a broken label in examples/python3/BUILD, should be fixed now 🤞

[chanseokoh]

Oh, and please resolve the merge conflict.

[mattmoor]

I'm also going to see what's left to move this to BASE_ARCHITECTURES now that I have the rest working, but running updateWorkspaceSnapshots.sh takes a really long time 😅

[mattmoor]

Pushing the changed now. I'm going to submit a fresh GCB run to confirm things work there now.

[mattmoor]

I forgot about the ld.so.{arch}.cache stuff, so until we have arm hardware to generate that on, we can't easily add Python support. This basically extends to all architectures that we don't have CI for because the verification that the cache is correct won't be running and we'll end up shipping stale files 😬

I've dropped arm from BASE for now, to try and unblock Kubernetes, and have another GCB run going with that to verify the latest version of these changes.

[mattmoor]

@chanseokoh this should be RFAL.

[chanseokoh]

Thanks for thoroughly testing this! I'll try to get back to this by EOD.

[chanseokoh]

LGTM. One minor suggestion.

[chanseokoh]

Thanks! Let's give it a spin.