Add Info request to post client (#5186)

## Motivation
Part of #5149 

This extends the `PostClient` to be able to fetch metadata about the PoST from the service

## Changes
- Add method to fetch metadata from PoST service

## Test Plan
- Tests were added for new functionality with and without TLS

## TODO
<!-- This section should be removed when all items are complete -->
- [x] Explain motivation or link existing issue(s)
- [x] Test changes and document test plan
- [x] Update documentation as needed
- [x] Update [changelog](../CHANGELOG.md) as needed

activation/interface.go

@@ -105,5 +105,6 @@ type postService interface {
 }
 
 type PostClient interface {
+	Info(ctx context.Context) (*types.PostInfo, error)
 	Proof(ctx context.Context, challenge []byte) (*types.Post, *types.PostMetadata, error)
 }

api/grpcserver/post_client.go

@@ -29,82 +29,132 @@ func newPostClient(con chan<- postCommand) *postClient {
 	}
 }
 
+func (pc *postClient) Info(ctx context.Context) (*types.PostInfo, error) {
+	req := &pb.NodeRequest{
+		Kind: &pb.NodeRequest_Metadata{
+			Metadata: &pb.MetadataRequest{},
+		},
+	}
+	resp, err := pc.send(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+	metadataResp := resp.GetMetadata()
+	if metadataResp == nil {
+		return nil, fmt.Errorf("unexpected response of type: %T", resp.GetKind())
+	}
+	meta := metadataResp.GetMeta()
+	if meta == nil {
+		return nil, fmt.Errorf("post metadata is nil")
+	}
+	var nonce *types.VRFPostIndex
+	if meta.Nonce != nil {
+		nonce = new(types.VRFPostIndex)
+		*nonce = types.VRFPostIndex(meta.GetNonce())
+	}
+	return &types.PostInfo{
+		NodeID:        types.BytesToNodeID(meta.GetNodeId()),
+		CommitmentATX: types.BytesToATXID(meta.GetCommitmentAtxId()),
+		Nonce:         nonce,
+
+		NumUnits:      meta.GetNumUnits(),
+		LabelsPerUnit: meta.GetLabelsPerUnit(),
+	}, nil
+}
+
 func (pc *postClient) Proof(ctx context.Context, challenge []byte) (*types.Post, *types.PostMetadata, error) {
-	resp := make(chan *pb.ServiceResponse, 1)
-	cmd := postCommand{
-		req: &pb.NodeRequest{
-			Kind: &pb.NodeRequest_GenProof{
-				GenProof: &pb.GenProofRequest{
-					Challenge: challenge,
-				},
+	req := &pb.NodeRequest{
+		Kind: &pb.NodeRequest_GenProof{
+			GenProof: &pb.GenProofRequest{
+				Challenge: challenge,
 			},
 		},
-		resp: resp,
 	}
 
+	var proofResp *pb.GenProofResponse
 	for {
-		// send command
-		select {
-		case <-pc.closed:
-			return nil, nil, fmt.Errorf("post client closed")
-		case <-ctx.Done():
-			return nil, nil, ctx.Err()
-		case pc.con <- cmd:
+		resp, err := pc.send(ctx, req)
+		if err != nil {
+			return nil, nil, err
+		}
+
+		proofResp = resp.GetGenProof()
+		if proofResp == nil {
+			return nil, nil, fmt.Errorf("unexpected response of type: %T", resp.GetKind())
+		}
+
+		switch proofResp.GetStatus() {
+		case pb.GenProofStatus_GEN_PROOF_STATUS_ERROR:
+			return nil, nil, fmt.Errorf("error generating proof: %s", proofResp)
+		case pb.GenProofStatus_GEN_PROOF_STATUS_UNSPECIFIED:
+			return nil, nil, fmt.Errorf("unspecified error generating proof: %s", proofResp)
+		case pb.GenProofStatus_GEN_PROOF_STATUS_OK:
+		default:
+			return nil, nil, fmt.Errorf("unknown status: %s", proofResp)
+		}
+
+		if proofResp.GetProof() != nil {
+			break
 		}
 
-		// receive response
 		select {
-		case <-pc.closed:
-			return nil, nil, fmt.Errorf("post client closed")
 		case <-ctx.Done():
 			return nil, nil, ctx.Err()
-		case resp := <-resp:
-			proofResp := resp.GetGenProof()
-			if proofResp == nil {
-				return nil, nil, fmt.Errorf("unexpected response of type: %T", resp.GetKind())
-			}
-			switch proofResp.GetStatus() {
-			case pb.GenProofStatus_GEN_PROOF_STATUS_OK:
-				if proofResp.GetProof() == nil {
-					select {
-					case <-ctx.Done():
-						return nil, nil, ctx.Err()
-					case <-time.After(2 * time.Second):
-						// TODO(mafa): make polling interval configurable
-						continue
-					}
-				}
-
-				proof := proofResp.GetProof()
-				proofMeta := proofResp.GetMetadata()
-				if proofMeta == nil {
-					return nil, nil, fmt.Errorf("proof metadata is nil")
-				}
-
-				if !bytes.Equal(proofMeta.GetChallenge(), challenge) {
-					return nil, nil, fmt.Errorf("unexpected challenge: %x", proofMeta.GetChallenge())
-				}
-
-				postMeta := proofMeta.GetMeta()
-				if postMeta == nil {
-					return nil, nil, fmt.Errorf("post metadata is nil")
-				}
-
-				return &types.Post{
-						Nonce:   proof.GetNonce(),
-						Indices: proof.GetIndices(),
-						Pow:     proof.GetPow(),
-					}, &types.PostMetadata{
-						Challenge:     proofMeta.GetChallenge(),
-						LabelsPerUnit: postMeta.GetLabelsPerUnit(),
-					}, nil
-			case pb.GenProofStatus_GEN_PROOF_STATUS_ERROR:
-				return nil, nil, fmt.Errorf("error generating proof: %s", proofResp)
-			case pb.GenProofStatus_GEN_PROOF_STATUS_UNSPECIFIED:
-				return nil, nil, fmt.Errorf("unspecified error generating proof: %s", proofResp)
-			}
+		case <-time.After(2 * time.Second):
+			// TODO(mafa): make polling interval configurable
+			continue
 		}
 	}
+
+	proof := proofResp.GetProof()
+	metadata := proofResp.GetMetadata()
+	if metadata == nil {
+		return nil, nil, fmt.Errorf("proof metadata is nil")
+	}
+	if !bytes.Equal(metadata.GetChallenge(), challenge) {
+		return nil, nil, fmt.Errorf("unexpected challenge: %x", metadata.GetChallenge())
+	}
+	proofMeta := metadata.GetMeta()
+	if proofMeta == nil {
+		return nil, nil, fmt.Errorf("post metadata is nil")
+	}
+	post := &types.Post{
+		Nonce:   proof.GetNonce(),
+		Indices: proof.GetIndices(),
+		Pow:     proof.GetPow(),
+	}
+	postMeta := &types.PostMetadata{
+		Challenge:     metadata.GetChallenge(),
+		LabelsPerUnit: proofMeta.GetLabelsPerUnit(),
+	}
+	return post, postMeta, nil
+}
+
+func (pc *postClient) send(ctx context.Context, req *pb.NodeRequest) (*pb.ServiceResponse, error) {
+	resp := make(chan *pb.ServiceResponse, 1)
+	cmd := postCommand{
+		req:  req,
+		resp: resp,
+	}
+
+	// send command
+	select {
+	case <-pc.closed:
+		return nil, fmt.Errorf("post client closed")
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	case pc.con <- cmd:
+	}
+
+	// receive response
+	select {
+	case <-pc.closed:
+		return nil, fmt.Errorf("post client closed")
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	case resp := <-resp:
+		return resp, nil
+	}
 }
 
 func (pc *postClient) Close() error {

api/grpcserver/post_service_test.go

@@ -23,7 +23,7 @@ import (
 	"github.com/spacemeshos/go-spacemesh/sql"
 )
 
-func initPost(tb testing.TB, log *zap.Logger, opts activation.PostSetupOpts) types.NodeID {
+func initPost(tb testing.TB, log *zap.Logger, opts activation.PostSetupOpts) (types.NodeID, types.ATXID) {
 	tb.Helper()
 
 	cfg := activation.DefaultPostConfig()
@@ -32,7 +32,7 @@ func initPost(tb testing.TB, log *zap.Logger, opts activation.PostSetupOpts) typ
 	require.NoError(tb, err)
 	id := sig.NodeID()
 
-	goldenATXID := types.ATXID{2, 3, 4}
+	goldenATXID := types.RandomATXID()
 
 	cdb := datastore.NewCachedDB(sql.InMemory(), logtest.New(tb))
 	mgr, err := activation.NewPostSetupManager(id, cfg, log.Named("manager"), cdb, goldenATXID)
@@ -69,7 +69,7 @@ func initPost(tb testing.TB, log *zap.Logger, opts activation.PostSetupOpts) typ
 	require.NoError(tb, mgr.StartSession(context.Background()))
 	require.NoError(tb, eg.Wait())
 	require.Equal(tb, activation.PostSetupStateComplete, mgr.Status().State)
-	return id
+	return id, goldenATXID
 }
 
 func launchPostSupervisor(tb testing.TB, log *zap.Logger, cfg Config, postOpts activation.PostSetupOpts) func() {
@@ -122,7 +122,7 @@ func Test_GenerateProof(t *testing.T) {
 	opts.DataDir = t.TempDir()
 	opts.ProviderID.SetInt64(int64(initialization.CPUProviderID()))
 	opts.Scrypt.N = 2 // Speedup initialization in tests.
-	id := initPost(t, log.Named("post"), opts)
+	id, _ := initPost(t, log.Named("post"), opts)
 	postCleanup := launchPostSupervisor(t, log.Named("supervisor"), cfg, opts)
 	t.Cleanup(postCleanup)
 
@@ -165,7 +165,7 @@ func Test_GenerateProof_TLS(t *testing.T) {
 	opts.DataDir = t.TempDir()
 	opts.ProviderID.SetInt64(int64(initialization.CPUProviderID()))
 	opts.Scrypt.N = 2 // Speedup initialization in tests.
-	id := initPost(t, log.Named("post"), opts)
+	id, _ := initPost(t, log.Named("post"), opts)
 	postCleanup := launchPostSupervisorTLS(t, log.Named("supervisor"), cfg, opts)
 	t.Cleanup(postCleanup)
 
@@ -198,7 +198,7 @@ func Test_GenerateProof_TLS(t *testing.T) {
 	require.Nil(t, meta)
 }
 
-func Test_Cancel_GenerateProof(t *testing.T) {
+func Test_GenerateProof_Cancel(t *testing.T) {
 	log := zaptest.NewLogger(t)
 	svc := NewPostService(log)
 	cfg, cleanup := launchServer(t, svc)
@@ -208,7 +208,7 @@ func Test_Cancel_GenerateProof(t *testing.T) {
 	opts.DataDir = t.TempDir()
 	opts.ProviderID.SetInt64(int64(initialization.CPUProviderID()))
 	opts.Scrypt.N = 2 // Speedup initialization in tests.
-	id := initPost(t, log.Named("post"), opts)
+	id, _ := initPost(t, log.Named("post"), opts)
 	t.Cleanup(launchPostSupervisor(t, log.Named("supervisor"), cfg, opts))
 
 	var client activation.PostClient
@@ -233,6 +233,46 @@ func Test_Cancel_GenerateProof(t *testing.T) {
 	require.Nil(t, meta)
 }
 
+func Test_Metadata(t *testing.T) {
+	log := zaptest.NewLogger(t)
+	svc := NewPostService(log)
+	cfg, cleanup := launchServer(t, svc)
+	t.Cleanup(cleanup)
+
+	opts := activation.DefaultPostSetupOpts()
+	opts.DataDir = t.TempDir()
+	opts.ProviderID.SetInt64(int64(initialization.CPUProviderID()))
+	opts.Scrypt.N = 2 // Speedup initialization in tests.
+	id, commitmentAtxId := initPost(t, log.Named("post"), opts)
+	postCleanup := launchPostSupervisor(t, log.Named("supervisor"), cfg, opts)
+	t.Cleanup(postCleanup)
+
+	var client activation.PostClient
+	require.Eventually(t, func() bool {
+		var err error
+		client, err = svc.Client(id)
+		return err == nil
+	}, 10*time.Second, 100*time.Millisecond, "timed out waiting for connection")
+
+	meta, err := client.Info(context.Background())
+	require.NoError(t, err)
+	require.NotNil(t, meta)
+	require.Equal(t, id, meta.NodeID)
+	require.Equal(t, commitmentAtxId, meta.CommitmentATX)
+	require.NotNil(t, meta.Nonce)
+	require.Equal(t, opts.NumUnits, meta.NumUnits)
+
+	// drop connection
+	postCleanup()
+	require.Eventually(t, func() bool {
+		meta, err = client.Info(context.Background())
+		return err != nil
+	}, 5*time.Second, 100*time.Millisecond)
+
+	require.ErrorContains(t, err, "post client closed")
+	require.Nil(t, meta)
+}
+
 func Test_GenerateProof_MultipleServices(t *testing.T) {
 	log := zaptest.NewLogger(t)
 	svc := NewPostService(log)
@@ -245,7 +285,7 @@ func Test_GenerateProof_MultipleServices(t *testing.T) {
 	opts.Scrypt.N = 2 // Speedup initialization in tests.
 
 	// all but one should not be able to register to the node (i.e. open a stream to it).
-	id := initPost(t, log.Named("post1"), opts)
+	id, _ := initPost(t, log.Named("post1"), opts)
 	t.Cleanup(launchPostSupervisor(t, log.Named("supervisor1"), cfg, opts))
 
 	opts.DataDir = t.TempDir()

common/types/post.go

@@ -0,0 +1,11 @@
+package types
+
+// PostInfo contains information about the PoST as returned by the service.
+type PostInfo struct {
+	NodeID        NodeID
+	CommitmentATX ATXID
+	Nonce         *VRFPostIndex
+
+	NumUnits      uint32
+	LabelsPerUnit uint64
+}