Add TODO comments for missing implementations.

Change default REST port to use 5052 (Lighthouse).
Add missing checks for maximum amount of validator ids.

beacon_chain/conf.nim

@@ -287,7 +287,7 @@ type
         name: "rest" }: bool
 
       restPort* {.
-        defaultValue: defaultEth2RpcPort
+        defaultValue: DefaultEth2RestPort
         desc: "HTTP port for the REST service"
         name: "rest-port" }: Port
 

beacon_chain/rpc/beacon_rest_api.nim

@@ -18,6 +18,11 @@ import
 
 logScope: topics = "rest_beaconapi"
 
+const
+  # https://github.com/ethereum/eth2.0-APIs/blob/master/apis/beacon/states/validator_balances.yaml#L17
+  # https://github.com/ethereum/eth2.0-APIs/blob/master/apis/beacon/states/validators.yaml#L17
+  MaximumValidatorIds = 30
+
 type
   ValidatorTuple = tuple
     index: ValidatorIndex
@@ -212,7 +217,11 @@ proc installBeaconApiHandlers*(router: var RestRouter, node: BeaconNode) =
         if id.isErr():
           return RestApiResponse.jsonError(Http400,
                                            "Invalid validator identifier(s)")
-        id.get()
+        let ires = id.get()
+        if len(ires) > MaximumValidatorIds:
+          return RestApiResponse.jsonError(Http400,
+                                         "Maximum number of id values exceeded")
+        ires
 
     let validatorsMask =
       block:
@@ -350,7 +359,11 @@ proc installBeaconApiHandlers*(router: var RestRouter, node: BeaconNode) =
         if id.isErr():
           return RestApiResponse.jsonError(Http400,
                                            "Invalid validator identifier(s)")
-        id.get()
+        let ires = id.get()
+        if len(ires) > MaximumValidatorIds:
+          return RestApiResponse.jsonError(Http400,
+                                         "Maximum number of id values exceeded")
+        ires
     let (keySet, indexSet) =
       block:
         var res1: HashSet[ValidatorPubKey]
@@ -471,6 +484,8 @@ proc installBeaconApiHandlers*(router: var RestRouter, node: BeaconNode) =
   # https://ethereum.github.io/eth2.0-APIs/#/Beacon/getBlockHeaders
   router.api(MethodGet, "/api/eth/v1/beacon/headers") do (
     slot: Option[Slot], parent_root: Option[Eth2Digest]) -> RestApiResponse:
+    # TODO (cheatfate): This call could not be implemented because structure
+    # of database do not allow to query blocks by `parent_root`.
     return RestApiResponse.jsonError(Http500, "Not implemented yet")
 
   # https://ethereum.github.io/eth2.0-APIs/#/Beacon/getBlockHeader

beacon_chain/rpc/event_rest_api.nim

@@ -51,7 +51,8 @@ proc validateEventTopics(events: seq[EventTopic]): Result[EventTopics,
 proc installEventApiHandlers*(router: var RestRouter, node: BeaconNode) =
   router.api(MethodGet, "/api/eth/v1/events") do (
     topics: seq[EventTopic]) -> RestApiResponse:
-
+    # TODO (cheatfate): This call is not fully implemented yet, because there
+    # missing infrastructure to raise/catch global events (eventbus).
     let eventTopics =
       block:
         if topics.isErr():

beacon_chain/rpc/validator_rest_api.nim

@@ -335,8 +335,8 @@ proc installValidatorApiHandlers*(router: var RestRouter, node: BeaconNode) =
   router.api(MethodPost,
              "/api/eth/v1/validator/beacon_committee_subscriptions") do (
     contentBody: Option[ContentBody]) -> RestApiResponse:
-    # TODO: This call could not be finished because more complex peer manager
-    # is needed.
+    # TODO (cheatfate): This call could not be finished because more complex
+    # peer manager implementation needed.
     let requests =
       block:
         if contentBody.isNone():

beacon_chain/spec/network.nim

@@ -30,6 +30,9 @@ const
   # This is not part of the spec yet! Keep in sync with BASE_RPC_PORT
   defaultEth2RpcPort* = 9190
 
+  # This is not part of the spec! But its port which uses Lighthouse
+  DefaultEth2RestPort* = 5052
+
 func getBeaconBlocksTopic*(forkDigest: ForkDigest): string =
   try:
     &"/eth2/{$forkDigest}/{topicBeaconBlocksSuffix}"