7390 block v2 fallback (Consensys#7637)

* Add block v2 fallback

ethereum/spec/src/main/java/tech/pegasys/teku/spec/logic/common/util/BlockProposalUtil.java

@@ -117,7 +117,12 @@ public SafeFuture<BeaconBlockAndState> createNewUnsignedBlock(
       final Bytes32 parentBlockSigningRoot,
       final Consumer<BeaconBlockBodyBuilder> bodyBuilder) {
     return createNewUnsignedBlock(
-        newSlot, proposerIndex, blockSlotState, parentBlockSigningRoot, bodyBuilder, true);
+        newSlot,
+        proposerIndex,
+        blockSlotState,
+        parentBlockSigningRoot,
+        bodyBuilder,
+        ValidatorsUtil.DEFAULT_PRODUCE_BLINDED_BLOCK);
   }
 
   private SafeFuture<? extends BeaconBlockBody> createBeaconBlockBody(

ethereum/spec/src/main/java/tech/pegasys/teku/spec/logic/common/util/ValidatorsUtil.java

@@ -35,6 +35,7 @@
 
 public class ValidatorsUtil {
 
+  public static final boolean DEFAULT_PRODUCE_BLINDED_BLOCK = true;
   private final SpecConfig specConfig;
   private final MiscHelpers miscHelpers;
   private final BeaconStateAccessors beaconStateAccessors;

validator/client/src/main/java/tech/pegasys/teku/validator/client/duties/BlockProductionDuty.java

@@ -103,7 +103,7 @@ private SafeFuture<BLSSignature> createRandaoReveal(final ForkInfo forkInfo) {
 
   private SafeFuture<Optional<BlockContainer>> createUnsignedBlock(
       final BLSSignature randaoReveal) {
-    if (this.blockV3Enabled) {
+    if (blockV3Enabled) {
       return validatorApiChannel.createUnsignedBlock(slot, randaoReveal, validator.getGraffiti());
     } else {
       return validatorApiChannel.createUnsignedBlock(

validator/remote/src/integration-test/java/tech/pegasys/teku/validator/remote/typedef/OkHttpValidatorTypeDefClientTest.java

@@ -15,6 +15,8 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assumptions.assumeThat;
+import static tech.pegasys.teku.infrastructure.unsigned.UInt64.ONE;
+import static tech.pegasys.teku.spec.SpecMilestone.DENEB;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -296,6 +298,44 @@ void registerValidators_fallbacksToJsonIfSszNotSupported() throws InterruptedExc
     verifyRegisterValidatorsPostRequest(mockWebServer.takeRequest(), JSON_CONTENT_TYPE);
   }
 
+  @TestTemplate
+  void blockV3ShouldFallbacksToBlockV2WhenNotFound()
+      throws JsonProcessingException, InterruptedException {
+    mockWebServer.enqueue(new MockResponse().setResponseCode(404));
+
+    final BlockContainer blockContainer;
+    if (specMilestone.isGreaterThanOrEqualTo(DENEB)) {
+      blockContainer = dataStructureUtil.randomBlindedBlockContents(ONE);
+    } else {
+      blockContainer = dataStructureUtil.randomBlindedBeaconBlock(ONE);
+    }
+
+    mockWebServer.enqueue(
+        new MockResponse()
+            .setResponseCode(200)
+            .setBody(
+                "{\"data\": "
+                    + serializeBlockContainer(blockContainer)
+                    + ", \"version\": \""
+                    + specMilestone
+                    + "\"}"));
+
+    final Optional<BlockContainer> producedBlock =
+        okHttpValidatorTypeDefClient.createUnsignedBlock(
+            dataStructureUtil.randomUInt64(),
+            dataStructureUtil.randomSignature(),
+            Optional.empty());
+
+    assertThat(producedBlock).hasValue(blockContainer);
+
+    assertThat(mockWebServer.getRequestCount()).isEqualTo(2);
+
+    final RecordedRequest firstRequest = mockWebServer.takeRequest();
+    assertThat(firstRequest.getPath()).startsWith("/eth/v3/validator/blocks");
+    final RecordedRequest secondRequest = mockWebServer.takeRequest();
+    assertThat(secondRequest.getPath()).startsWith("/eth/v1/validator/blinded_blocks");
+  }
+
   private void verifyRegisterValidatorsPostRequest(
       final RecordedRequest recordedRequest, final String expectedContentType) {
     assertThat(recordedRequest.getPath()).isEqualTo("/eth/v1/validator/register_validator");
@@ -315,6 +355,9 @@ private void assertJsonEquals(final String actual, final String expected) {
   private String serializeBlockContainer(final BlockContainer blockContainer)
       throws JsonProcessingException {
     return JsonUtil.serialize(
-        blockContainer, schemaDefinitions.getBlockContainerSchema().getJsonTypeDefinition());
+        blockContainer,
+        blockContainer.isBlinded()
+            ? schemaDefinitions.getBlindedBlockContainerSchema().getJsonTypeDefinition()
+            : schemaDefinitions.getBlockContainerSchema().getJsonTypeDefinition());
   }
 }

validator/remote/src/main/java/tech/pegasys/teku/validator/remote/typedef/BlockProductionV3FailedException.java

@@ -0,0 +1,16 @@
+/*
+ * Copyright Consensys Software Inc., 2023
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+
+package tech.pegasys.teku.validator.remote.typedef;
+
+public class BlockProductionV3FailedException extends RuntimeException {}

validator/remote/src/main/java/tech/pegasys/teku/validator/remote/typedef/OkHttpValidatorTypeDefClient.java

@@ -28,6 +28,7 @@
 import tech.pegasys.teku.spec.datastructures.builder.SignedValidatorRegistration;
 import tech.pegasys.teku.spec.datastructures.genesis.GenesisData;
 import tech.pegasys.teku.spec.datastructures.operations.AttestationData;
+import tech.pegasys.teku.spec.logic.common.util.ValidatorsUtil;
 import tech.pegasys.teku.validator.api.SendSignedBlockResult;
 import tech.pegasys.teku.validator.api.required.SyncingStatus;
 import tech.pegasys.teku.validator.remote.typedef.handlers.CreateAttestationDataRequest;
@@ -111,7 +112,13 @@ public Optional<BlockContainer> createUnsignedBlock(
       final UInt64 slot, final BLSSignature randaoReveal, final Optional<Bytes32> graffiti) {
     final ProduceBlockRequest produceBlockRequest =
         new ProduceBlockRequest(baseEndpoint, okHttpClient, spec, slot, preferSszBlockEncoding);
-    return produceBlockRequest.createUnsignedBlock(randaoReveal, graffiti);
+    try {
+      return produceBlockRequest.createUnsignedBlock(randaoReveal, graffiti);
+    } catch (final BlockProductionV3FailedException ex) {
+      LOG.warn("Produce Block V3 request failed at slot {}. Retrying with Block V2", slot);
+      return createUnsignedBlock(
+          slot, randaoReveal, graffiti, ValidatorsUtil.DEFAULT_PRODUCE_BLINDED_BLOCK);
+    }
   }
 
   public void registerValidators(

validator/remote/src/main/java/tech/pegasys/teku/validator/remote/typedef/handlers/ProduceBlockRequest.java

@@ -13,6 +13,7 @@
 
 package tech.pegasys.teku.validator.remote.typedef.handlers;
 
+import static tech.pegasys.teku.infrastructure.http.HttpStatusCodes.SC_NOT_FOUND;
 import static tech.pegasys.teku.infrastructure.http.HttpStatusCodes.SC_OK;
 import static tech.pegasys.teku.infrastructure.http.RestApiConstants.CONSENSUS_BLOCK_VALUE;
 import static tech.pegasys.teku.infrastructure.http.RestApiConstants.EXECUTION_PAYLOAD_BLINDED;
@@ -45,6 +46,7 @@
 import tech.pegasys.teku.spec.SpecMilestone;
 import tech.pegasys.teku.spec.datastructures.blocks.BlockContainer;
 import tech.pegasys.teku.spec.datastructures.blocks.BlockContainerSchema;
+import tech.pegasys.teku.validator.remote.typedef.BlockProductionV3FailedException;
 import tech.pegasys.teku.validator.remote.typedef.ResponseHandler;
 
 public class ProduceBlockRequest extends AbstractTypeDefRequest {
@@ -56,7 +58,6 @@ public class ProduceBlockRequest extends AbstractTypeDefRequest {
   private final BlockContainerSchema<BlockContainer> blockContainerSchema;
   private final BlockContainerSchema<BlockContainer> blindedBlockContainerSchema;
   private final ResponseHandler<ProduceBlockResponse> responseHandler;
-
   public final DeserializableOneOfTypeDefinition<ProduceBlockResponse> produceBlockTypeDefinition;
 
   public ProduceBlockRequest(
@@ -91,7 +92,12 @@ public ProduceBlockRequest(
 
     this.responseHandler =
         new ResponseHandler<>(produceBlockTypeDefinition)
-            .withHandler(SC_OK, this::handleBlockContainerResult);
+            .withHandler(SC_OK, this::handleBlockContainerResult)
+            .withHandler(
+                SC_NOT_FOUND,
+                (__, ___) -> {
+                  throw new BlockProductionV3FailedException();
+                });
   }
 
   public Optional<BlockContainer> createUnsignedBlock(