fix: store config without db-path leads SIGSEGV (#1218)

waku/v2/node/storage/message/sqlite_store/sqlite_store.nim

@@ -19,6 +19,10 @@ logScope:
 
 
 proc init(db: SqliteDatabase): MessageStoreResult[void] =
+  ## Misconfiguration can lead to nil DB
+  if db.isNil():
+    return err("db not initialized")
+
   # Create table, if doesn't exist
   let resCreate = createTable(db)
   if resCreate.isErr():

waku/v2/node/storage/peer/waku_peer_storage.nim

@@ -61,6 +61,9 @@ proc encode*(storedInfo: StoredInfo): PeerStorageResult[ProtoBuffer] =
 ##########################
 
 proc new*(T: type WakuPeerStorage, db: SqliteDatabase): PeerStorageResult[T] =
+  ## Misconfiguration can lead to nil DB
+  if db.isNil():
+    return err("db not initialized")
   
   ## Create the "Peer" table
   ## It contains:

waku/v2/node/wakunode2.nim

@@ -886,20 +886,25 @@ when isMainModule:
         storeTuple.pStorage = res.value
 
     if conf.persistMessages:
-      if conf.sqliteStore: 
+      if conf.sqliteStore:
+        debug "setting up sqlite-only store"
         let res = SqliteStore.init(sqliteDatabase)
         if res.isErr():
           warn "failed to init message store", err = res.error
           waku_node_errors.inc(labelValues = ["init_store_failure"])
         else:
           storeTuple.mStorage = res.value
-      else: 
+      elif not sqliteDatabase.isNil():
+        debug "setting up dual message store"
         let res = DualMessageStore.init(sqliteDatabase, conf.storeCapacity)
         if res.isErr():
           warn "failed to init message store", err = res.error
           waku_node_errors.inc(labelValues = ["init_store_failure"])
         else:
           storeTuple.mStorage = res.value
+      else:
+        debug "setting up in-memory store"
+        storeTuple.mStorage = StoreQueueRef.new(conf.storeCapacity)
 
     ok(storeTuple)