getPayloadV2 support for capella (#4457)

* getPayloadV2 support for capella

* check execution payload type more rigorously

beacon_chain/eth1/eth1_monitor.nim

@@ -543,8 +543,9 @@ proc getBlockByNumber*(p: Web3DataProviderRef,
   except ValueError as exc: raiseAssert exc.msg # Never fails
   p.web3.provider.eth_getBlockByNumber(hexNumber, false)
 
-proc getPayload*(p: Eth1Monitor,
-                 payloadId: bellatrix.PayloadID): Future[engine_api.ExecutionPayloadV1] =
+proc getPayloadV1*(
+    p: Eth1Monitor, payloadId: bellatrix.PayloadID):
+    Future[engine_api.ExecutionPayloadV1] =
   # Eth1 monitor can recycle connections without (external) warning; at least,
   # don't crash.
   if p.isNil or p.dataProvider.isNil:
@@ -554,6 +555,18 @@ proc getPayload*(p: Eth1Monitor,
 
   p.dataProvider.web3.provider.engine_getPayloadV1(FixedBytes[8] payloadId)
 
+proc getPayloadV2*(
+    p: Eth1Monitor, payloadId: bellatrix.PayloadID):
+    Future[engine_api.ExecutionPayloadV2] =
+  # Eth1 monitor can recycle connections without (external) warning; at least,
+  # don't crash.
+  if p.isNil or p.dataProvider.isNil:
+    let epr = newFuture[engine_api.ExecutionPayloadV2]("getPayload")
+    epr.complete(default(engine_api.ExecutionPayloadV2))
+    return epr
+
+  p.dataProvider.web3.provider.engine_getPayloadV2(FixedBytes[8] payloadId)
+
 proc newPayload*(p: Eth1Monitor, payload: engine_api.ExecutionPayloadV1):
     Future[PayloadStatusV1] =
   # Eth1 monitor can recycle connections without (external) warning; at least,

beacon_chain/validators/validator_duties.nim

@@ -319,10 +319,15 @@ proc get_execution_payload[EP](
   else:
     when EP is bellatrix.ExecutionPayload:
       asConsensusExecutionPayload(
-        await execution_engine.getPayload(payload_id.get))
-    else:
-      debugRaiseAssert $capellaImplementationMissing & ": implement getPayload V2"
+        await execution_engine.getPayloadV1(payload_id.get))
+    elif EP is capella.ExecutionPayload:
+      asConsensusExecutionPayload(
+        await execution_engine.getPayloadV2(payload_id.get))
+    elif EP is eip4844.ExecutionPayload:
+      debugRaiseAssert $eip4844ImplementationMissing & ": get_execution_payload"
       default(EP)
+    else:
+      static: doAssert "unknown execution payload type"
 
 proc getFeeRecipient(node: BeaconNode,
                      pubkey: ValidatorPubKey,