Add cosa push-container-manifest command

This will create and push a container manifest (i.e. one that contains
multiple images from different architectures) to a remote registry.

(cherry picked from commit 8e5ad58)

jlebon: Had to manually add `push-container-manifest` to the entrypoint.

src/cmd-push-container-manifest

@@ -0,0 +1,57 @@
+#!/usr/bin/python3
+
+# Push a container manifest (i.e. multi-arch) to a container registry based on
+# arguments provided by ther user.
+
+# The inverse of cmd-buildfetch (i.e. we upload a build which later can be
+# partially re-downloaded with cmd-buildfetch).
+
+import argparse
+import os
+import sys
+from cosalib.container_manifest import create_and_push_container_manifest
+
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+
+
+def main():
+    args = parse_args()
+    if args.authfile:
+        os.environ["REGISTRY_AUTH_FILE"] = args.authfile
+    create_and_push_container_manifest(
+        args.repo, args.tag, args.images, args.v2s2)
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(
+        prog="CoreOS Assembler Push Container Manifest",
+        description="Create and push a container manifest to a registry",
+        usage="""
+Examples:
+    export REGISTRY_AUTH_FILE=/path/to/auth.json
+    cosa push-container-manifest \\
+        --repo quay.io/dustymabe/coreos-assembler --tag latest \\
+        --image docker://quay.io/dustymabe/coreos-assembler:x86_64-6864566 \\
+        --image docker://quay.io/dustymabe/coreos-assembler:s390x-6864566 \\
+        --image docker://quay.io/dustymabe/coreos-assembler:aarch64-6864566
+
+    cosa push-container-manifest \\
+        --repo quay.io/dustymabe/fedora-coreos --tag stable \\
+        --image oci-archive://builds/36.20220716.3.1/x86_64/fedora-coreos-37.20220725.91.0-ostree.x86_64.ociarchive \\
+        --image oci-archive://builds/36.20220716.3.1/aarch64/fedora-coreos-37.20220725.91.0-ostree.aarch64.ociarchive \\
+        --image oci-archive://builds/36.20220716.3.1/s390x/fedora-coreos-37.20220725.91.0-ostree.s390x.ociarchive""")
+    parser.add_argument("--repo", required=True, help="The registry repo to target for the manifest")
+    parser.add_argument("--tag", required=True, help="The tag of the manifest to use")
+    parser.add_argument("--authfile", help="A file to use for registry auth")
+    parser.add_argument('--v2s2', action='store_true',
+                        help='Use old image manifest version2 schema 2 format')
+    parser.add_argument("--images", required=True, action='append', default=[],
+                        help="""The images to add to the manifest. Can be specified multiple times like
+                        --image docker://quay.io/dustymabe/coreos-assembler:s390x-686456
+                        --image oci-archive://path/to/cosa-aarch64-686456.ociarchive""")
+
+    return parser.parse_args()
+
+
+if __name__ == '__main__':
+    sys.exit(main())

src/coreos-assembler

@@ -43,7 +43,7 @@ cmd=${1:-}
 # commands we'd expect to use in the local dev path
 build_commands="init fetch build run prune clean list"
 # commands more likely to be used in a prod pipeline only
-advanced_build_commands="buildfetch buildupload oc-adm-release upload-oscontainer"
+advanced_build_commands="buildfetch buildupload oc-adm-release push-container-manifest upload-oscontainer"
 buildextend_commands="aliyun aws azure digitalocean exoscale gcp ibmcloud live metal metal4k nutanix openstack qemu vmware vultr"
 utility_commands="aws-replicate compress generate-hashlist koji-upload kola remote-prune sign tag"
 other_commands="shell meta"