Complete DA height polling implementation with CLI support and documentation

Copilot · julienrbrt · Copilot · commit cf39baae73ca · 2025-08-25T10:15:26.000Z
Co-authored-by: julienrbrt &lt;29894366+julienrbrt@users.noreply.github.com&gt;
diff --git a/docs/DA_HEIGHT_POLLING.md b/docs/DA_HEIGHT_POLLING.md
@@ -0,0 +1,94 @@
+# DA Height Polling for Genesis Initialization
+
+This feature allows non-aggregator nodes to automatically poll the DA (Data Availability) height from an aggregator node during genesis initialization, eliminating the need to manually configure the DA start height.
+
+## How It Works
+
+When a non-aggregator node starts with a genesis configuration where `genesis_da_start_height` is zero (or equivalently, `GenesisDAStartTime` is zero time), it will automatically poll the configured aggregator endpoint to get the current DA height before proceeding with chain initialization.
+
+## Configuration
+
+### For Non-Aggregator Nodes
+
+Add the aggregator endpoint to your configuration:
+
+```yaml
+da:
+  aggregator_endpoint: http://aggregator-node:7331
+```
+
+Or via command line:
+
+```bash
+evnode start --evnode.da.aggregator_endpoint=http://aggregator-node:7331
+```
+
+### For Aggregator Nodes
+
+No additional configuration needed. Aggregator nodes automatically expose the `/da/height` endpoint when DA visualization is enabled.
+
+## Genesis File Setup
+
+For non-aggregator nodes to trigger automatic DA height polling, the genesis file should have a zero DA start time:
+
+```json
+{
+  "chain_id": "my-chain",
+  "genesis_da_start_height": "1970-01-01T00:00:00Z",
+  "initial_height": 1,
+  "proposer_address": "..."
+}
+```
+
+## Workflow Example
+
+1. **Aggregator Node Setup:**
+   ```bash
+   # Start an aggregator node
+   evnode start --evnode.node.aggregator
+   ```
+
+2. **Non-Aggregator Node Setup:**
+   ```bash
+   # Initialize non-aggregator node with aggregator endpoint
+   evnode init --evnode.da.aggregator_endpoint=http://aggregator:7331
+   
+   # Start non-aggregator node (will automatically poll DA height)
+   evnode start
+   ```
+
+## API Endpoint
+
+Aggregator nodes expose the following endpoint:
+
+**GET `/da/height`**
+
+Returns the current DA layer height:
+
+```json
+{
+  "height": 1234,
+  "timestamp": "2023-11-15T10:30:15Z"
+}
+```
+
+## Polling Behavior
+
+- **Timeout:** 5 minutes maximum
+- **Interval:** 5 seconds between polls
+- **Condition:** Only triggers when `genesis_da_start_height` is zero and node is not an aggregator
+- **Fallback:** If no aggregator endpoint is configured, uses current time
+
+## Error Handling
+
+If the polling fails:
+- The node will log the error and fail to start
+- Check that the aggregator endpoint is reachable
+- Verify the aggregator node has the DA height endpoint available
+- Ensure the aggregator node is running and has advanced beyond height 0
+
+## Use Cases
+
+- **Simplified Deployment:** No need to manually coordinate DA start heights
+- **Dynamic Chain Launching:** Non-aggregator nodes can join automatically
+- **Development Testing:** Easy setup for multi-node test networks
diff --git a/pkg/config/config.go b/pkg/config/config.go
@@ -302,6 +302,7 @@ func AddFlags(cmd *cobra.Command) {
 	cmd.Flags().String(FlagDASubmitOptions, def.DA.SubmitOptions, "DA submit options")
 	cmd.Flags().Uint64(FlagDAMempoolTTL, def.DA.MempoolTTL, "number of DA blocks until transaction is dropped from the mempool")
 	cmd.Flags().Int(FlagDAMaxSubmitAttempts, def.DA.MaxSubmitAttempts, "maximum number of attempts to submit data to the DA layer before giving up")
+	cmd.Flags().String(FlagDAAggregatorEndpoint, def.DA.AggregatorEndpoint, "HTTP endpoint of an aggregator node to poll for DA height during genesis initialization (only used by non-aggregator nodes when genesis DA start time is zero)")
 
 	// P2P configuration flags
 	cmd.Flags().String(FlagP2PListenAddress, def.P2P.ListenAddress, "P2P listen address (host:port)")
diff --git a/pkg/rpc/server/templates/da_visualization.html b/pkg/rpc/server/templates/da_visualization.html
@@ -153,6 +153,24 @@ <h4><span class="method method-get">GET</span> /da/health</h4>
                 <li><code>unknown</code> - Insufficient data to determine health</li>
             </ul>
         </div>
+
+        <div class="api-endpoint">
+            <h4><span class="method method-get">GET</span> /da/height</h4>
+            <p>Returns the current DA layer height. Used by non-aggregator nodes for genesis polling.</p>
+            <p><strong>Note:</strong> Only available on aggregator nodes.</p>
+            <p><strong>Example:</strong> <code>curl http://localhost:8080/da/height</code></p>
+            <div class="api-response">
+                <strong>Response:</strong>
+                <pre>{
+  "height": 1234,
+  "timestamp": "2023-11-15T10:30:15Z"
+}</pre>
+            </div>
+            <p style="margin-top: 10px; font-size: 13px; color: #666;">
+                This endpoint is used during genesis initialization when non-aggregator nodes need to poll 
+                the DA height from an aggregator node (when <code>genesis_da_start_height</code> is zero).
+            </p>
+        </div>
     </div>
     {{end}}
 
diff --git a/scripts/demo_da_height_polling.sh b/scripts/demo_da_height_polling.sh
@@ -0,0 +1,86 @@
+#!/bin/bash
+
+# Demo script for DA height polling functionality
+# This script demonstrates how to use the new DA height polling feature
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(dirname "$SCRIPT_DIR")"
+TESTAPP_BIN="$PROJECT_ROOT/build/testapp"
+TEMP_DIR=$(mktemp -d)
+
+echo "🚀 Demo: DA Height Polling for Genesis Initialization"
+echo "=================================================="
+
+# Ensure testapp is built
+if [ ! -f "$TESTAPP_BIN" ]; then
+    echo "❌ testapp binary not found at $TESTAPP_BIN"
+    echo "Please run 'make build' first"
+    exit 1
+fi
+
+echo "✅ testapp binary found at $TESTAPP_BIN"
+
+# Create directories for two nodes
+AGG_HOME="$TEMP_DIR/aggregator"
+FULL_HOME="$TEMP_DIR/fullnode"
+
+echo "📁 Setting up temporary directories:"
+echo "   Aggregator: $AGG_HOME"
+echo "   Full node:  $FULL_HOME"
+
+# Initialize aggregator node
+echo ""
+echo "🔧 Initializing aggregator node..."
+"$TESTAPP_BIN" init \
+    --home="$AGG_HOME" \
+    --chain_id=demo-chain \
+    --evnode.node.aggregator \
+    --evnode.signer.passphrase=test123
+
+echo "✅ Aggregator initialized"
+
+# Initialize full node with aggregator endpoint
+echo ""
+echo "🔧 Initializing full node with aggregator endpoint..."
+"$TESTAPP_BIN" init \
+    --home="$FULL_HOME" \
+    --chain_id=demo-chain \
+    --evnode.da.aggregator_endpoint=http://localhost:7331
+
+echo "✅ Full node initialized"
+
+# Show the configuration files
+echo ""
+echo "📄 Full node configuration (showing DA config):"
+echo "------------------------------------------------"
+grep -A 10 "^da:" "$FULL_HOME/config/evnode.yaml" || echo "❌ Could not find DA config"
+
+echo ""
+echo "🎯 Key points demonstrated:"
+echo "1. ✅ New --evnode.da.aggregator_endpoint flag is available"
+echo "2. ✅ Configuration is properly saved to evnode.yaml"
+echo "3. ✅ Non-aggregator nodes can be configured to poll DA height"
+
+echo ""
+echo "🧪 To test the actual polling (requires running nodes):"
+echo "   1. Start aggregator: $TESTAPP_BIN start --home=$AGG_HOME --evnode.signer.passphrase=test123"
+echo "   2. Test DA height endpoint: curl http://localhost:7331/da/height"
+echo "   3. Start full node: $TESTAPP_BIN start --home=$FULL_HOME"
+echo "      (The full node will automatically poll DA height if genesis DA start time is zero)"
+
+# Cleanup function
+cleanup() {
+    echo ""
+    echo "🧹 Cleaning up temporary files..."
+    rm -rf "$TEMP_DIR"
+    echo "✅ Cleanup complete"
+}
+
+# Register cleanup function
+trap cleanup EXIT
+
+echo ""
+echo "✨ Demo completed successfully!"
+echo "   Temp directory: $TEMP_DIR (will be cleaned up on exit)"
diff --git a/test/integration/da_height_polling_test.go b/test/integration/da_height_polling_test.go
@@ -0,0 +1,99 @@
+package integration
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	coreda "github.com/evstack/ev-node/core/da"
+	"github.com/evstack/ev-node/pkg/config"
+	"github.com/evstack/ev-node/pkg/da_client"
+	genesispkg "github.com/evstack/ev-node/pkg/genesis"
+	"github.com/evstack/ev-node/pkg/rpc/server"
+	"github.com/rs/zerolog"
+)
+
+// TestDAHeightPollingIntegration tests the end-to-end DA height polling functionality
+func TestDAHeightPollingIntegration(t *testing.T) {
+	logger := zerolog.Nop()
+
+	// Step 1: Create a simulated aggregator with DummyDA
+	dummyDA := coreda.NewDummyDA(1024, 0, 0, 50*time.Millisecond)
+	dummyDA.StartHeightTicker()
+	defer dummyDA.StopHeightTicker()
+
+	// Wait for DA height to increment to > 0
+	time.Sleep(100 * time.Millisecond)
+
+	// Create aggregator's DA visualization server
+	aggregatorServer := server.NewDAVisualizationServer(dummyDA, logger, true)
+	server.SetDAVisualizationServer(aggregatorServer) // Set the global server instance
+
+	// Set up HTTP test server to simulate the aggregator using the public HTTP endpoints
+	mux := http.NewServeMux()
+	server.RegisterCustomHTTPEndpoints(mux) // This will register all the endpoints including /da/height
+	testAggregator := httptest.NewServer(mux)
+	defer testAggregator.Close()
+
+	// Step 2: Test DA client polling functionality
+	client := da_client.NewClient()
+	
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	height, err := client.GetDAHeight(ctx, testAggregator.URL)
+	if err != nil {
+		t.Fatalf("Failed to get DA height from aggregator: %v", err)
+	}
+
+	if height == 0 {
+		t.Errorf("Expected DA height > 0, got %d", height)
+	}
+
+	t.Logf("Successfully polled DA height: %d", height)
+
+	// Step 3: Test polling functionality (simulates genesis initialization)
+	pollHeight, err := client.PollDAHeight(ctx, testAggregator.URL, 100*time.Millisecond)
+	if err != nil {
+		t.Fatalf("Failed to poll DA height: %v", err)
+	}
+
+	if pollHeight == 0 {
+		t.Errorf("Expected polled DA height > 0, got %d", pollHeight)
+	}
+
+	t.Logf("Successfully polled DA height via polling: %d", pollHeight)
+}
+
+// TestGenesisPollingConfig tests the configuration and genesis modification logic
+func TestGenesisPollingConfig(t *testing.T) {
+	// Test configuration with aggregator endpoint
+	cfg := config.DefaultConfig
+	cfg.DA.AggregatorEndpoint = "http://localhost:8080"
+	cfg.Node.Aggregator = false // This is a non-aggregator node
+
+	// Verify the configuration is set correctly
+	if cfg.DA.AggregatorEndpoint == "" {
+		t.Error("Expected aggregator endpoint to be set")
+	}
+
+	if cfg.Node.Aggregator {
+		t.Error("Expected node to be non-aggregator for this test")
+	}
+
+	// Test genesis with zero start time (simulating the condition that triggers polling)
+	genesis := genesispkg.Genesis{
+		ChainID:            "test-chain",
+		GenesisDAStartTime: time.Time{}, // Zero time
+		InitialHeight:      1,
+		ProposerAddress:    []byte("test-proposer"),
+	}
+
+	if !genesis.GenesisDAStartTime.IsZero() {
+		t.Error("Expected genesis DA start time to be zero")
+	}
+
+	t.Log("Configuration test passed - ready for DA height polling")
+}
