node-split-poc: calculate eligibility on epoch's first layer

[kacpersaw]

Description

This pull request introduces a new API endpoint to calculate eligibility slots for a given node in a specific epoch. With that smesher service can calculate eligibility proofs at the start of the epoch.

Also, fixed standalone mode.

New API Endpoint for Eligibility Slots:

• api/node/client/client.gen.go: Added GetEligibilitySlotsNodeEpoch method to the ClientInterface and ClientWithResponsesInterface, and implemented the request and response handling for this new endpoint. [1] [2] [3] [4] [5] [6] [7]

Node Service Enhancements:

• api/node/client/client.go: Added CalculateEligibilitySlotsFor method to the NodeService to call the new API endpoint and handle the response.

API Specification Update:

• api/node/node_service.yaml: Defined the new /eligibility/slots/{node}/{epoch} endpoint in the API specification.

Server and Middleware Updates:

• api/node/server/server.gen.go: Updated server interface and middleware to include the new endpoint, and added corresponding request and response objects. [1] [2] [3] [4] [5] [6]
• api/node/server/server.go: Implemented the server-side logic for the new endpoint. [1] [2] [3]

Mock and Testing Enhancements:

• api/node/server/mocks.go: Added mock methods to support testing of the new CalculateEligibilitySlotsFor functionality.

Dependency Update:

• go.mod: Updated the github.com/spacemeshos/api/release/go dependency to the latest version.

[poszu]

How about exporting it and then you can avoid using a custom x-spacemesh-atx-nonce header?

Suggested change

	nonce types.VRFPostIndex
	Nonce types.VRFPostIndex

[poszu]

I think you need a session only:

Suggested change

	signer := &signerSession{}
	if err := pb.initSignerSessionData(&signer.session, epoch.FirstLayer(), node); err != nil {
	return 0, 0, err
	}
	return signer.session.eligibilities.slots, signer.session.nonce, nil
	var session session
	if err := pb.initSignerSessionData(&session, epoch.FirstLayer(), node); err != nil {
	return 0, 0, err
	}
	return session.eligibilities.slots, session.nonce, nil

[poszu]

What if the node is down during the first layer? It's safer to calculate slots whenever the eligibilities[nodeId] is vacant. Perhaps you could fetch slots and calculate eligibilties here:

go-spacemesh/miner/remote_proposals.go

Lines 139 to 143 in 913a87a

	if e := current.GetEpoch(); e > epoch {
	eligibilities = make(map[types.NodeID]map[types.LayerID][]types.VotingEligibility)
	epochBeacon = make(map[types.EpochID]types.Beacon)
	epoch = e
	}