feat: implement KeyManager API (#1246)

Author: avilagaston9

README.md

@@ -90,7 +90,8 @@ Some public endpoints can be found in [eth-clients.github.io/checkpoint-sync-end
 > The data retrieved from the URL is stored in the DB once the node is initiated (i.e. the iex prompt shows).
 > Once this happens, following runs of `make iex` will start the node using that data.
 
-### Beacon API
+### APIs
+#### Beacon API
 
 You can start the application with the Beacon API on the default port `4000` running:
 ```shell
@@ -100,7 +101,27 @@ make start
 You can also specify a port with the "--beacon-api-port" flag:
 
 ```shell
-iex -S mix run -- --beacon-api --beacon-api-port <your_port_here>
+iex -S mix run --  --beacon-api-port <your_port_here>
+```
+> [!WARNING]
+> In case checkpoint-sync is needed, following the instructions above will end immediately with an error (see [Checkpoint Sync](#checkpoint-sync)).
+>
+
+#### Key-Manager API
+
+Implemented following the [Ethereum specification](https://ethereum.github.io/keymanager-APIs/#/).
+
+You can start the application with the key manager API on the default port `5000` running:
+
+```shell
+iex -S mix run -- --validator-api
+```
+
+
+You can also specify a port with the "--validator-api-port" flag:
+
+```shell
+iex -S mix run -- --validator-api-port <your_port_here>
 ```
 > [!WARNING]
 > In case checkpoint-sync is needed, following the instructions above will end immediately with an error (see [Checkpoint Sync](#checkpoint-sync)).
@@ -250,6 +271,7 @@ participants:
     use_separate_vc: false
     count: 1
     cl_max_mem: 4096
+    keymanager_enabled: true
 ```
 
 ### Kurtosis Execution and Make tasks

config/runtime.exs

@@ -18,6 +18,8 @@ switches = [
   log_file: :string,
   beacon_api: :boolean,
   beacon_api_port: :integer,
+  validator_api: :boolean,
+  validator_api_port: :integer,
   listen_address: [:string, :keep],
   discovery_port: :integer,
   boot_nodes: :string,
@@ -47,6 +49,8 @@ metrics_port = Keyword.get(args, :metrics_port, nil)
 enable_metrics = Keyword.get(args, :metrics, not is_nil(metrics_port))
 beacon_api_port = Keyword.get(args, :beacon_api_port, nil)
 enable_beacon_api = Keyword.get(args, :beacon_api, not is_nil(beacon_api_port))
+validator_api_port = Keyword.get(args, :validator_api_port, nil)
+enable_validator_api = Keyword.get(args, :validator_api, not is_nil(validator_api_port))
 listen_addresses = Keyword.get_values(args, :listen_address)
 discovery_port = Keyword.get(args, :discovery_port, 9000)
 cli_bootnodes = Keyword.get(args, :boot_nodes, "")
@@ -153,6 +157,16 @@ config :lambda_ethereum_consensus, BeaconApi.Endpoint,
     layout: false
   ]
 
+# KeyStore API
+config :lambda_ethereum_consensus, KeyStoreApi.Endpoint,
+  server: enable_validator_api,
+  http: [port: validator_api_port || 5000],
+  url: [host: "localhost"],
+  render_errors: [
+    formats: [json: KeyStoreApi.ErrorJSON],
+    layout: false
+  ]
+
 # Validator setup
 
 if (keystore_dir != nil and keystore_pass_dir == nil) or