cmd-push-container-manifest: store arch-specific digest in meta.json

As discussed in #3122,
ART needs the arch-specific digest in the `meta.json` rather than the
manifest list digest. FCOS isn't planning to use the digest so doesn't
care about which one gets chosen.

Update `cosa push-container-manifest` to use the arch-specific digest.

Author: jlebon

src/cmd-push-container-manifest

@@ -6,7 +6,6 @@
 import argparse
 import os
 import sys
-import tempfile
 from cosalib.container_manifest import create_and_push_container_manifest
 from cosalib.builds import Builds
 from cosalib.meta import GenericBuildMeta
@@ -22,7 +21,7 @@ def main():
     if args.images:
         # User provided images directly
         create_and_push_container_manifest(
-            args.repo, args.tags, args.images, args.v2s2, None)
+            args.repo, args.tags, args.images, args.v2s2)
     else:
         # Picking up images from artifacts in meta.json
         builds = Builds()
@@ -60,19 +59,24 @@ def main():
             images.append(f"oci-archive:{ociarchive}")
 
         # Create/Upload the manifest list to the container registry
-        with tempfile.NamedTemporaryFile() as digestfile:
-            create_and_push_container_manifest(
-                args.repo, args.tags, images, args.v2s2, digestfile.name)
-            digestfile.seek(0)
-            digest = digestfile.read().decode('utf-8').strip()
+        manifest_info = create_and_push_container_manifest(
+            args.repo, args.tags, images, args.v2s2)
 
-        # Update the meta.json in each build/arch metadata
-        for _, buildmeta in buildmetas.items():
-            buildmeta[args.metajsonname] = {
+        # Update the `meta.json` files. Note the digest included is the
+        # arch-specific one for each individual arch, and not the manifest list
+        # digest. See: https://github.com/coreos/coreos-assembler/issues/3122.
+        assert len(manifest_info['manifests']) == len(buildmetas)
+        for manifest in manifest_info['manifests']:
+            arch = manifest['platform']['architecture']
+            if arch == 'arm64':
+                arch = 'aarch64'
+            elif arch == 'amd64':
+                arch = 'x86_64'
+            buildmetas[arch][args.metajsonname] = {
                 'image': args.repo,
-                'digest': digest
+                'digest': manifest['digest']
             }
-            buildmeta.write(artifact_name=args.metajsonname)
+            buildmetas[arch].write(artifact_name=args.metajsonname)
 
 
 def parse_args():

src/cosalib/container_manifest.py

@@ -1,9 +1,11 @@
+import json
+
 from cosalib.cmdlib import runcmd
 
 
-def create_local_container_manifest(repo, tag, images):
+def create_local_container_manifest(repo, tag, images) -> dict:
     '''
-    Create local manifest list
+    Create local manifest list and return the final manifest JSON
     @param images list of image specifications (including transport)
     @param repo str registry repository
     @param tag str manifest tag
@@ -13,6 +15,9 @@ def create_local_container_manifest(repo, tag, images):
     for image in images:
         cmd = ["podman", "manifest", "add", f"{repo}:{tag}", image]
         runcmd(cmd)
+    manifest_info = runcmd(["podman", "manifest", "inspect", f"{repo}:{tag}"],
+                           capture_output=True).stdout
+    return json.loads(manifest_info)
 
 
 def delete_local_container_manifest(repo, tag):
@@ -25,12 +30,11 @@ def delete_local_container_manifest(repo, tag):
     runcmd(cmd)
 
 
-def push_container_manifest(repo, tags, digestfile, v2s2=False):
+def push_container_manifest(repo, tags, v2s2=False):
     '''
     Push manifest to registry
     @param repo str registry repository
     @param tags list of tags to push
-    @param digestfile str write container digest to file
     @param v2s2 boolean use to force v2s2 format
     '''
     base_cmd = ["podman", "manifest", "push", "--all", f"{repo}:{tags[0]}"]
@@ -39,22 +43,20 @@ def push_container_manifest(repo, tags, digestfile, v2s2=False):
         # to create a manifest with 2 different mediaType. It seems to be
         # a Quay issue.
         base_cmd.extend(["--remove-signatures", "-f", "v2s2"])
-    if digestfile:
-        base_cmd.extend([f"--digestfile={digestfile}"])
     runcmd(base_cmd + [f"{repo}:{tags[0]}"])
     for tag in tags[1:]:
         runcmd(base_cmd + [f"{repo}:{tag}"])
 
 
-def create_and_push_container_manifest(repo, tags, images, v2s2, digestfile):
+def create_and_push_container_manifest(repo, tags, images, v2s2) -> dict:
     '''
-    Do it all! Create, Push, Cleanup
+    Do it all! Create, push, cleanup, and return the final manifest JSON.
     @param repo str registry repository
     @param tags list of tags
     @param images list of image specifications (including transport)
     @param v2s2 boolean use to force v2s2 format
-    @param digestfile str write container digest to file
     '''
-    create_local_container_manifest(repo, tags[0], images)
-    push_container_manifest(repo, tags, digestfile, v2s2)
+    manifest_info = create_local_container_manifest(repo, tags[0], images)
+    push_container_manifest(repo, tags, v2s2)
     delete_local_container_manifest(repo, tags[0])
+    return manifest_info