Pushing multiple container images clobbers build metadata values

[jlebon]

Right now in OCP we're pushing the rhel-9.6 image to both Quay.io and registry.ci using the new capabilities added in #1091. The problem is that the cosa schema only supports specifying a single pushed repository. But ideally we include all of them and not just the last one in the list (which is what currently happens).

The relevant part of the schema is here: https://github.com/coreos/coreos-assembler/blob/837190dffb5d5cc56b9815ff937a6196eeb4205e/src/v1.json#L50-L87.

I think probably the cleanest, even though it's still awkward, is to add a primary-image object to the schema which sources the image object's properties, but also adds a new additional-images property. This property is then a list type of image objects.

And then in cosa push-container-manifest, if the primary object already exists for the image we're pushing, add it to the additional-images list in that object instead.

[jbtrystram]

Why not simply make oscontainer and the others an array ? I don't see what a primary and additional adds, as they are all the same images ?

[jbtrystram]

e.g.

diff --git a/src/v1.json b/src/v1.json
index f7d75843b..c9ec2d645 100644
--- a/src/v1.json
+++ b/src/v1.json
@@ -700,7 +700,7 @@
     },
     "oscontainer": {
       "$id": "#/properties/oscontainer",
-      "type": "object",
+      "type": "array",
       "title": "Oscontainer",
       "$ref": "#/definitions/image"
     },
@@ -919,7 +919,7 @@
     },
     "base-oscontainer": {
       "$id": "#/properties/base-oscontainer",
-      "type": "object",
+      "type": "array",
       "title": "Base OS container",
       "$ref": "#/definitions/image"
     },

[jlebon]

Unfortunately, we can't change existing types because it would render existing meta.jsons invalid. We'd have to do a schema version bump, which doesn't seem worth it.

Putting my proposal in JSON:

{
    ...
    "base-oscontainer": {
        "image": "...",
        "digest": "...",
        "tags": [...],
        "additional-images": [
            {
                "image": "...",
                "digest": "...",
                "tags": [...]
            },
            ...
        ]
    },
}