go/consensus: Show a list of available checkpoints

Author: martintomazic

.changelog/5265.feature.md

@@ -0,0 +1,8 @@
+go/oasis-node: Display checkpoints height and block header hash
+
+A new field `checkpoints` has been added to the `oasis-node control status`
+output under the `consensus` status section. Unless empty, this field displays
+a list of local checkpoints with the following information:
+
+ 1. The height for which checkpoint was created.
+ 2. The bock header hash of the given checkpoint.

go/consensus/api/api.go

@@ -375,6 +375,9 @@ type Status struct { // nolint: maligned
 
 	// P2P is the P2P status of the node.
 	P2P *P2PStatus `json:"p2p,omitempty"`
+
+	// Checkpoints is the list of node's local checkpoints.
+	Checkpoints []*Checkpoint `json:"checkpoints,omitempty"`
 }
 
 // P2PStatus is the P2P status of a node.
@@ -392,6 +395,14 @@ type P2PStatus struct {
 	Peers []string `json:"peers"`
 }
 
+// Checkpoint is the checkpoint's metadata.
+type Checkpoint struct {
+	// Height is the height at which the checkpoint was created.
+	Height uint64 `json:"height"`
+	// BlockHash is the hash of the block header at the given height.
+	BlockHash hash.Hash `json:"block_hash"`
+}
+
 // Service is an interface that a consensus backend service must provide.
 type Service interface {
 	service.BackgroundService

go/consensus/cometbft/full/common.go

@@ -840,6 +840,21 @@ func (n *commonNode) GetStatus(ctx context.Context) (*consensusAPI.Status, error
 			// Failed to load validator set.
 			status.IsValidator = false
 		}
+
+		cps, err := n.mux.State().Storage().GetCheckpoints(ctx, &checkpoint.GetCheckpointsRequest{
+			Version: 1,
+		})
+		switch err {
+		case nil:
+			for _, cp := range cps {
+				status.Checkpoints = append(status.Checkpoints, &consensusAPI.Checkpoint{
+					Height:    cp.Root.Version,
+					BlockHash: cp.Root.Hash,
+				})
+			}
+		default:
+			return nil, fmt.Errorf("failed to fetch checkpoints: %w", err)
+		}
 	}
 
 	return status, nil