Add MessageIdProvider for `WakuRelay` (#803)

* Add MessageIdProvider

* Fix unit test. Changelog.

CHANGELOG.md

@@ -15,6 +15,9 @@ which is a sequence of string.
 - All `HistoryResponse` messages are now auto-paginated to a maximum of 100 messages per response
 - Increased maximum length for reading from a libp2p input stream to allow largest possible protocol messages, including `HistoryResponse` messages at max size.
 
+### Fixes
+- Added GossipSub `MessageIdProvider` for `11/WAKU2-RELAY` messages.
+
 ## 2021-11-05 v0.6
 
 Some useful features and fixes in this release, include:

tests/v2/test_jsonrpc_waku.nim

@@ -128,8 +128,10 @@ procSuite "Waku v2 JSON-RPC API":
       node3 = WakuNode.new(nodeKey3, bindIp, Port(60003), some(extIp), some(port))
       pubSubTopic = "polling"
       contentTopic = defaultContentTopic
-      payload = @[byte 9]
-      message = WakuMessage(payload: payload, contentTopic: contentTopic)
+      payload1 = @[byte 9]
+      message1 = WakuMessage(payload: payload1, contentTopic: contentTopic)
+      payload2 = @[byte 8]
+      message2 = WakuMessage(payload: payload2, contentTopic: contentTopic)
 
     await node1.start()
     node1.mountRelay(@[pubSubTopic])
@@ -157,7 +159,7 @@ procSuite "Waku v2 JSON-RPC API":
     await client.connect("127.0.0.1", rpcPort)
 
     # First see if we can retrieve messages published on the default topic (node is already subscribed)
-    await node2.publish(defaultTopic, message)
+    await node2.publish(defaultTopic, message1)
 
     await sleepAsync(2000.millis)
 
@@ -166,7 +168,7 @@ procSuite "Waku v2 JSON-RPC API":
     check:
       messages.len == 1
       messages[0].contentTopic == contentTopic
-      messages[0].payload == payload
+      messages[0].payload == payload1
     
     # Ensure that read messages are cleared from cache
     messages = await client.get_waku_v2_relay_v1_messages(pubSubTopic)  
@@ -184,7 +186,7 @@ procSuite "Waku v2 JSON-RPC API":
       response == true
 
     # Now publish a message on node1 and see if we receive it on node3
-    await node1.publish(pubSubTopic, message)
+    await node1.publish(pubSubTopic, message2)
 
     await sleepAsync(2000.millis)
     
@@ -193,7 +195,7 @@ procSuite "Waku v2 JSON-RPC API":
     check:
       messages.len == 1
       messages[0].contentTopic == contentTopic
-      messages[0].payload == payload
+      messages[0].payload == payload2
     
     # Ensure that read messages are cleared from cache
     messages = await client.get_waku_v2_relay_v1_messages(pubSubTopic)  

waku/v2/node/wakunode2.nim

@@ -1,7 +1,7 @@
 {.push raises: [Defect].}
 
 import
-  std/[options, tables, strutils, sequtils, os],
+  std/[hashes, options, tables, strutils, sequtils, os],
   chronos, chronicles, metrics,
   stew/shims/net as stewNet,
   stew/byteutils,
@@ -9,9 +9,9 @@ import
   eth/p2p/discoveryv5/enr,
   libp2p/crypto/crypto,
   libp2p/protocols/ping,
-  libp2p/protocols/pubsub/gossipsub,
+  libp2p/protocols/pubsub/[gossipsub, rpc/messages],
   libp2p/nameresolving/dnsresolver,
-  libp2p/builders,
+  libp2p/[builders, multihash],
   libp2p/transports/[transport, tcptransport, wstransport],
   ../protocol/[waku_relay, waku_message],
   ../protocol/waku_store/waku_store,
@@ -632,12 +632,18 @@ proc mountRelay*(node: WakuNode,
                  relayMessages = true,
                  triggerSelf = true)
   # @TODO: Better error handling: CatchableError is raised by `waitFor`
-  {.gcsafe, raises: [Defect, InitializationError, LPError, CatchableError].} = 
+  {.gcsafe, raises: [Defect, InitializationError, LPError, CatchableError].} =
+
+  func msgIdProvider(m: messages.Message): seq[byte] =
+    let mh = MultiHash.digest("sha2-256", m.data)
+    if mh.isOk():
+      return mh[].data.buffer
+    else:
+      return ($m.data.hash).toBytes()
 
   let wakuRelay = WakuRelay.init(
     switch = node.switch,
-    # Use default
-    #msgIdProvider = msgIdProvider,
+    msgIdProvider = msgIdProvider,
     triggerSelf = triggerSelf,
     sign = false,
     verifySignature = false,