Add bones of execution_layer

beacon_node/execution_layer/src/engine_api.rs

@@ -0,0 +1,35 @@
+use async_trait::async_trait;
+use eth1::http::RpcError;
+
+pub use types::{Address, Hash256};
+
+pub mod http;
+
+pub type PayloadId = u64;
+
+#[derive(Debug)]
+pub enum Error {
+    Reqwest(reqwest::Error),
+    BadResponse(String),
+    RequestFailed(String),
+    JsonRpc(RpcError),
+}
+
+impl From<reqwest::Error> for Error {
+    fn from(e: reqwest::Error) -> Self {
+        Error::Reqwest(e)
+    }
+}
+
+#[async_trait]
+pub trait EngineApi {
+    async fn upcheck(&self) -> Result<(), Error>;
+
+    async fn prepare_payload(
+        &self,
+        parent_hash: Hash256,
+        timestamp: u64,
+        random: Hash256,
+        fee_recipient: Address,
+    ) -> Result<PayloadId, Error>;
+}