chore: Enabling to use a full node for lightpush via rest api without lightpush client configured (#2626)

* Enabling to use a full node for lightpush via rest api without light push client configured

waku/node/waku_node.nim

@@ -44,6 +44,7 @@ import
   ../waku_lightpush/client as lightpush_client,
   ../waku_lightpush/common,
   ../waku_lightpush/protocol,
+  ../waku_lightpush/self_req_handler,
   ../waku_enr,
   ../waku_peer_exchange,
   ../waku_rln_relay,
@@ -913,7 +914,7 @@ proc mountLightPush*(
 
       if publishedCount == 0:
         ## Agreed change expected to the lightpush protocol to better handle such case. https://github.com/waku-org/pm/issues/93
-        debug("Lightpush request has not been published to any peers")
+        debug "Lightpush request has not been published to any peers"
 
       return ok()
 
@@ -942,15 +943,30 @@ proc lightpushPublish*(
   ## Returns whether relaying was successful or not.
   ## `WakuMessage` should contain a `contentTopic` field for light node
   ## functionality.
-  if node.wakuLightpushClient.isNil():
-    return err("waku lightpush client is nil")
+  if node.wakuLightpushClient.isNil() and node.wakuLightPush.isNil():
+    error "failed to publish message as lightpush not available"
+    return err("Waku lightpush not available")
+
+  let internalPublish = proc(
+      node: WakuNode,
+      pubsubTopic: PubsubTopic,
+      message: WakuMessage,
+      peer: RemotePeerInfo,
+  ): Future[WakuLightPushResult[void]] {.async, gcsafe.} =
+    if not node.wakuLightpushClient.isNil():
+      debug "publishing message with lightpush",
+        pubsubTopic = pubsubTopic,
+        contentTopic = message.contentTopic,
+        peer = peer.peerId
+      return await node.wakuLightpushClient.publish(pubsubTopic, message, peer)
+
+    if not node.wakuLightPush.isNil():
+      debug "publishing message with self hosted lightpush",
+        pubsubTopic = pubsubTopic, contentTopic = message.contentTopic
+      return await node.wakuLightPush.handleSelfLightPushRequest(pubsubTopic, message)
 
   if pubsubTopic.isSome():
-    debug "publishing message with lightpush",
-      pubsubTopic = pubsubTopic.get(),
-      contentTopic = message.contentTopic,
-      peer = peer.peerId
-    return await node.wakuLightpushClient.publish(pubsubTopic.get(), message, peer)
+    return await internalPublish(node, pubsubTopic.get(), message, peer)
 
   let topicMapRes = node.wakuSharding.parseSharding(pubsubTopic, message.contentTopic)
 
@@ -961,9 +977,7 @@ proc lightpushPublish*(
       topicMapRes.get()
 
   for pubsub, _ in topicMap.pairs: # There's only one pair anyway
-    debug "publishing message with lightpush",
-      pubsubTopic = pubsub, contentTopic = message.contentTopic, peer = peer.peerId
-    return await node.wakuLightpushClient.publish($pubsub, message, peer)
+    return await internalPublish(node, $pubsub, message, peer)
 
 # TODO: Move to application module (e.g., wakunode2.nim)
 proc lightpushPublish*(
@@ -971,16 +985,19 @@ proc lightpushPublish*(
 ): Future[WakuLightPushResult[void]] {.
     async, gcsafe, deprecated: "Use 'node.lightpushPublish()' instead"
 .} =
-  if node.wakuLightpushClient.isNil():
-    let msg = "waku lightpush client is nil"
-    error "failed to publish message", msg = msg
-    return err(msg)
+  if node.wakuLightpushClient.isNil() and node.wakuLightPush.isNil():
+    error "failed to publish message as lightpush not available"
+    return err("waku lightpush not available")
 
-  let peerOpt = node.peerManager.selectPeer(WakuLightPushCodec)
-  if peerOpt.isNone():
-    let msg = "no suitable remote peers"
-    error "failed to publish message", msg = msg
-    return err(msg)
+  var peerOpt: Option[RemotePeerInfo] = none(RemotePeerInfo)
+  if not node.wakuLightpushClient.isNil():
+    peerOpt = node.peerManager.selectPeer(WakuLightPushCodec)
+    if peerOpt.isNone():
+      let msg = "no suitable remote peers"
+      error "failed to publish message", msg = msg
+      return err(msg)
+  elif not node.wakuLightPush.isNil():
+    peerOpt = some(RemotePeerInfo.init($node.switch.peerInfo.peerId))
 
   let publishRes =
     await node.lightpushPublish(pubsubTopic, message, peer = peerOpt.get())

waku/waku_api/rest/builder.nim

@@ -177,7 +177,10 @@ proc startRestServerProtocolSupport*(
   rest_store_legacy_api.installStoreApiHandlers(router, node, storeDiscoHandler)
 
   ## Light push API
-  if conf.lightpushnode != "" and node.wakuLightpushClient != nil:
+  ## Install it either if lightpushnode (lightpush service node) is configured and client is mounted)
+  ## or install it to be used with self-hosted lightpush service
+  if (conf.lightpushnode != "" and node.wakuLightpushClient != nil) or
+      (conf.lightpush and node.wakuLightPush != nil and node.wakuRelay != nil):
     let lightDiscoHandler =
       if wakuDiscv5.isSome():
         some(defaultDiscoveryHandler(wakuDiscv5.get(), Lightpush))

waku/waku_api/rest/lightpush/handlers.nim

@@ -16,6 +16,7 @@ import
   ../../waku/node/peer_manager,
   ../../../waku_node,
   ../../waku/waku_lightpush/common,
+  ../../waku/waku_lightpush/self_req_handler,
   ../../handlers,
   ../serdes,
   ../responses,
@@ -35,6 +36,9 @@ const NoPeerNoDiscoError =
 const NoPeerNoneFoundError =
   RestApiResponse.serviceUnavailable("No suitable service peer & none discovered")
 
+proc useSelfHostedLightPush(node: WakuNode): bool =
+  return node.wakuLightPush != nil and node.wakuLightPushClient == nil
+
 #### Request handlers
 
 const ROUTE_LIGHTPUSH* = "/lightpush/v1/message"
@@ -60,15 +64,19 @@ proc installLightPushRequestHandler*(
     let msg = req.message.toWakuMessage().valueOr:
       return RestApiResponse.badRequest("Invalid message: " & $error)
 
-    let peer = node.peerManager.selectPeer(WakuLightPushCodec).valueOr:
-      let handler = discHandler.valueOr:
-        return NoPeerNoDiscoError
+    var peer = RemotePeerInfo.init($node.switch.peerInfo.peerId)
+    if useSelfHostedLightPush(node):
+      discard
+    else:
+      peer = node.peerManager.selectPeer(WakuLightPushCodec).valueOr:
+        let handler = discHandler.valueOr:
+          return NoPeerNoDiscoError
 
-      let peerOp = (await handler()).valueOr:
-        return RestApiResponse.internalServerError("No value in peerOp: " & $error)
+        let peerOp = (await handler()).valueOr:
+          return RestApiResponse.internalServerError("No value in peerOp: " & $error)
 
-      peerOp.valueOr:
-        return NoPeerNoneFoundError
+        peerOp.valueOr:
+          return NoPeerNoneFoundError
 
     let subFut = node.lightpushPublish(req.pubsubTopic, msg, peer)
 

waku/waku_lightpush/self_req_handler.nim

@@ -0,0 +1,53 @@
+when (NimMajor, NimMinor) < (1, 4):
+  {.push raises: [Defect].}
+else:
+  {.push raises: [].}
+
+## Notice that the REST /lightpush requests normally assume that the node
+## is acting as a lightpush-client that will trigger the service provider node
+## to relay the message.
+## In this module, we allow that a lightpush service node (full node) can be
+## triggered directly through the  REST /lightpush endpoint.
+## The typical use case for that is when using `nwaku-compose`,
+## which spawn a full service Waku node
+## that could be used also as a lightpush client, helping testing and development.
+
+import stew/results, chronos, chronicles, std/options, metrics
+import
+  ../waku_core,
+  ./protocol,
+  ./common,
+  ./rpc,
+  ./rpc_codec,
+  ./protocol_metrics,
+  ../utils/requests
+
+proc handleSelfLightPushRequest*(
+    self: WakuLightPush, pubSubTopic: PubsubTopic, message: WakuMessage
+): Future[WakuLightPushResult[void]] {.async.} =
+  ## Handles the lightpush requests made by the node to itself.
+  ## Normally used in REST-lightpush requests
+
+  try:
+    # provide self peerId as now this node is used directly, thus there is no light client sender peer.
+    let selfPeerId = self.peerManager.switch.peerInfo.peerId
+
+    let req = PushRequest(pubSubTopic: pubSubTopic, message: message)
+    let rpc = PushRPC(requestId: generateRequestId(self.rng), request: some(req))
+
+    let respRpc = await self.handleRequest(selfPeerId, rpc.encode().buffer)
+
+    if respRpc.response.isNone():
+      waku_lightpush_errors.inc(labelValues = [emptyResponseBodyFailure])
+      return err(emptyResponseBodyFailure)
+
+    let response = respRpc.response.get()
+    if not response.isSuccess:
+      if response.info.isSome():
+        return err(response.info.get())
+      else:
+        return err("unknown failure")
+
+    return ok()
+  except Exception:
+    return err("exception in handleSelfLightPushRequest: " & getCurrentExceptionMsg())