Rethinking the ActorTemplate and ActorTemplateVersion relationship, inspired by ActorSnapshotTag

[Zoe Zhao (zoez7)]

Previously, the ActorTemplate object expressed both a group and a pointer.

• It's a grouping mechanism of ActorTemplateVersions.
• It has a pointer to one of the ATVs, the pointer is default_version_on_create.

In this modified API, we separate out the "pointer" into ActorTemplateVersionTag, similar to ActorSnapshotTag.
After this, the ActorTemplate resource itself doesn't have any field anymore, therefore the "ActorTemplate" as a grouping concept only exists as an ID string.

• ATVTag is more flexible, is not restricted to default_version_on_create only.
• below is an illustration of the relationships. This PR doesn't have rollout policy, but we can add that in the future.

// +-- Actor Template    -----------------------------------+
// |                                                        |
// |   +------------+            rollout policy             |
// |   | DefaultTag |             /        \                |
// |   +------------+        10% /          \ 90%           |
// |         |                  /            \              |
// |         v                 v              v             |
// |     +-------+         +-------+      +-------+         |
// |     | ATV-1 |         | ATV-2 |      | ATV-3 |         |
// |     +-------+         +-------+      +-------+         |
// +--------------------------------------------------------+

Julian Gutierrez Oschmann (@juli4n) Let me know what you think.

Initial API definition only, haven't run "go generate" yet.

[Haven Xia (HavenXia)]

Why we need the actor_template_id here if you can extract it from actor_template_version? Is it to save one read?

[Zoe Zhao (zoez7)]

This is useful to support APIs like ListActorTemplateVersionTags(actor_template_id), so we don't have to first list all ATVs by actor_template_version

[Haven Xia (HavenXia)]

Who will generate the id? There's no message ActorTemplate anymore

[Zoe Zhao (zoez7)]

The user will decide this. Perhaps calling it application_name would be more appropriate.

[Zoe Zhao (zoez7)]

That's a good point actually, the server would need to keep record of mapping between (name <-> id)

[Krisztian F (krisztianfekete)]

This field is where ate.template.name comes from, and it's a metric label today. We are also planning to leverage it in #853. Can we ensure this is globally unique?

[YuanM (mini-cookie)]

Good mr！I want to add support for the E2B protocol. Building on the ActorTemplateVersion design, we should be able to implement the fork and checkpoint endpoints in ate-api-server fairly quickly～