go/scheduler: Validators now returns validators by node ID

The consensus ID isn't all that useful for most external callers, so
querying it should just return the validators by node ID instead.

.changelog/2739.feature.md

@@ -0,0 +1,4 @@
+go/scheduler: Validators now returns validators by node ID
+
+The consensus ID isn't all that useful for most external callers, so
+querying it should just return the validators by node ID instead.

go/consensus/tendermint/apps/registry/query.go

@@ -30,18 +30,22 @@ type QueryFactory struct {
 	app *registryApplication
 }
 
-// QueryAt returns the registry query interface for a specific height.
-func (sf *QueryFactory) QueryAt(ctx context.Context, height int64) (Query, error) {
-	var state *registryState.ImmutableState
-	var err error
+// ImmutableStateAt creates a registry ImmutableState suitable for use
+// from external query instances.
+func ImmutableStateAt(ctx context.Context, appState abci.ApplicationState, height int64) (*registryState.ImmutableState, error) {
+	var (
+		state *registryState.ImmutableState
+		err   error
+	)
 	abciCtx := abci.FromCtx(ctx)
+	abciState := abciCtx.State()
 
 	// If this request was made from InitChain, no blocks and states have been
 	// submitted yet, so we use the existing state instead.
 	if abciCtx != nil && abciCtx.IsInitChain() {
-		state = registryState.NewMutableState(abciCtx.State()).ImmutableState
+		state = registryState.NewMutableState(abciState).ImmutableState
 	} else {
-		state, err = registryState.NewImmutableState(sf.app.state, height)
+		state, err = registryState.NewImmutableState(appState, height)
 		if err != nil {
 			return nil, err
 		}
@@ -50,7 +54,17 @@ func (sf *QueryFactory) QueryAt(ctx context.Context, height int64) (Query, error
 	// If this request was made from an ABCI app, make sure to use the associated
 	// context for querying state instead of the default one.
 	if abciCtx != nil && height == abciCtx.BlockHeight()+1 {
-		state.Snapshot = abciCtx.State().ImmutableTree
+		state.Snapshot = abciState.ImmutableTree
+	}
+
+	return state, nil
+}
+
+// QueryAt returns the registry query interface for a specific height.
+func (sf *QueryFactory) QueryAt(ctx context.Context, height int64) (Query, error) {
+	state, err := ImmutableStateAt(ctx, sf.app.state, height)
+	if err != nil {
+		return nil, err
 	}
 
 	return &registryQuerier{sf.app, state, height}, nil

go/consensus/tendermint/apps/scheduler/query.go

@@ -5,6 +5,8 @@ import (
 
 	consensus "github.com/oasislabs/oasis-core/go/consensus/api"
 	"github.com/oasislabs/oasis-core/go/consensus/tendermint/abci"
+	registryapp "github.com/oasislabs/oasis-core/go/consensus/tendermint/apps/registry"
+	registryState "github.com/oasislabs/oasis-core/go/consensus/tendermint/apps/registry/state"
 	schedulerState "github.com/oasislabs/oasis-core/go/consensus/tendermint/apps/scheduler/state"
 	scheduler "github.com/oasislabs/oasis-core/go/scheduler/api"
 )
@@ -45,11 +47,18 @@ func (sf *QueryFactory) QueryAt(ctx context.Context, height int64) (Query, error
 		state.Snapshot = abciCtx.State().ImmutableTree
 	}
 
-	return &schedulerQuerier{state}, nil
+	// Some queries need access to the registry to give useful responses.
+	regState, err := registryapp.ImmutableStateAt(ctx, sf.app.state, height)
+	if err != nil {
+		return nil, err
+	}
+
+	return &schedulerQuerier{state, regState}, nil
 }
 
 type schedulerQuerier struct {
-	state *schedulerState.ImmutableState
+	state    *schedulerState.ImmutableState
+	regState *registryState.ImmutableState
 }
 
 func (sq *schedulerQuerier) Validators(ctx context.Context) ([]*scheduler.Validator, error) {
@@ -63,8 +72,21 @@ func (sq *schedulerQuerier) Validators(ctx context.Context) ([]*scheduler.Valida
 	// ABCI state.
 	ret := make([]*scheduler.Validator, 0, len(valPks))
 	for _, v := range valPks {
+		// The validator list uses consensus addresses, so convert them
+		// to node identifiers.
+		//
+		// This is probably better than switching the scheduler to use
+		// node identifiers for validators, because user queries are
+		// likely more infrequent than all the business of actually
+		// scheduling...
+		node, err := sq.regState.NodeByConsensusOrP2PKey(v)
+		if err != nil {
+			// Should NEVER happen.
+			return nil, err
+		}
+
 		ret = append(ret, &scheduler.Validator{
-			ID:          v,
+			ID:          node.ID,
 			VotingPower: consensus.VotingPower,
 		})
 	}

go/scheduler/api/api.go

@@ -150,7 +150,7 @@ func (c *Committee) EncodedMembersHash() hash.Hash {
 
 // Validator is a consensus validator.
 type Validator struct {
-	// ID is the validator consensus (NOT oasis) identifier.
+	// ID is the validator Oasis node identifier.
 	ID signature.PublicKey `json:"id"`
 
 	// VotingPower is the validator's consensus voting power.