LN: pass openchannel args from graphml file to ln node

Author: pinheadmz

docs/lightning.md

@@ -17,17 +17,18 @@ Example:
 
 ## Adding LN channels to graph
 
-LN channels are represented in the graphml file as edges with an extra data element
-with key `"channel"` and a value in satoshis representing channel capacity. Note
-that this data element is the only difference between LN channels and regular bitcoin
-p2p connections. The graph will be considered a `MultiDiGraph` and contain two different
-kinds of edges.
+LN channels are represented in the graphml file as edges with extra data elements
+that correspond to arguments to the lnd `openchannel` and `updatechanpolicy` RPC
+commands. The keys are with either `"source-policy"` (arguments added to `openchannel`)
+or `"target-policy"` (arguments added to `updatechanpolicy`). Therefore, the key `"source-policy"` is
+required to open a LN channel in warnet, and to identify an edge in the graphml file
+as a LN channel.
 
 Example:
 
 ```
     <edge id="0" source="0" target="1">
-        <data key="channel">100000</data>
+        <data key="source-policy">--local_amt=100000</data>
     </edge>
 ```
 

src/scenarios/ln_init.py

@@ -50,12 +50,12 @@ def run_test(self):
         ln_edges = []
         for edge in self.warnet.graph.edges(data=True):
             (src, dst, data) = edge
-            if "channel" in data:
+            if "source-policy" in data:
                 src_node = self.warnet.get_ln_node_from_tank(src)
                 assert src_node is not None
                 assert self.warnet.get_ln_node_from_tank(dst) is not None
                 ln_edges.append(edge)
-                tx = src_node.open_channel_to_tank(dst, data["channel"])["funding_txid"]
+                tx = src_node.open_channel_to_tank(dst, data["source-policy"])["funding_txid"]
                 opening_txs.append(tx)
 
         self.log.info("Waiting for all channel open txs in mempool")

src/warnet/lnnode.py

@@ -73,10 +73,10 @@ def get_wallet_balance(self):
         res = self.lncli("walletbalance")
         return res
 
-    def open_channel_to_tank(self, index, amt):
+    def open_channel_to_tank(self, index: int, policy: str) -> str:
         tank = self.warnet.tanks[index]
         [pubkey, host] = tank.lnnode.getURI().split("@")
-        res = self.lncli(f"openchannel --node_key={pubkey} --connect={host} --local_amt={amt}")
+        res = self.lncli(f"openchannel --node_key={pubkey} --connect={host} {policy}")
         return res
 
     def connect_to_tank(self, index):

src/warnet/warnet.py

@@ -150,7 +150,8 @@ def tanks_from_graph(self):
             # import edges as list of destinations to connect to
             for edge in self.graph.edges(data=True):
                 (src, dst, data) = edge
-                if "channel" in data:
+                # Ignore LN edges for now
+                if "source-policy" in data:
                     continue
                 if src == node_id:
                     tank.init_peers.append(int(dst))

test/data/ln.graphml

@@ -6,21 +6,21 @@
   <key attr.name="ln_image"       attr.type="string" for="node" id="ln_image"/>
   <key attr.name="ln_cb_image"    attr.type="string" for="node" id="ln_cb_image"/>
   <key attr.name="ln_config"      attr.type="string" for="node" id="ln_config"/>
-  <key attr.name="channel"        attr.type="string" for="edge" id="channel"/>
+  <key attr.name="source-policy"  attr.type="string" for="edge" id="source-policy"/>
   <key attr.name="collect_logs"   attr.type="boolean" for="node" id="collect_logs"/>
   <key attr.name="image"          attr.type="string" for="node" id="image"/>
   <graph edgedefault="directed">
     <node id="0">
         <data key="version">26.0</data>
         <data key="bitcoin_config">-uacomment=w0</data>
         <data key="ln">lnd</data>
+        <data key="ln_image">lightninglabs/lnd:v0.15.5-beta</data>
         <data key="collect_logs">true</data>
     </node>
     <node id="1">
         <data key="version">26.0</data>
         <data key="bitcoin_config">-uacomment=w1</data>
         <data key="ln">lnd</data>
-        <data key="ln_image">lightninglabs/lnd:v0.15.5-beta</data>
         <data key="ln_cb_image">pinheadmz/circuitbreaker:278737d</data>
         <data key="collect_logs">true</data>
         <data key="ln_config">--bitcoin.timelockdelta=20</data>
@@ -41,10 +41,10 @@
     <edge id="4" source="3" target="0"></edge>
     <!-- LN channels -->
     <edge id="5" source="0" target="1">
-        <data key="channel">100000</data>
+        <data key="source-policy">--local_amt=100000</data>
     </edge>
     <edge id="6" source="1" target="2">
-        <data key="channel">100000</data>
+        <data key="source-policy">--local_amt=100000 --push_amt=50000 --base_fee_msat=5500 --fee_rate_ppm=3</data>
     </edge>
   </graph>
 </graphml>

test/ln_test.py

@@ -44,7 +44,7 @@ def get_cb_forwards(index):
 base.warcli("scenarios run ln_init")
 base.wait_for_all_scenarios()
 
-print("\nEnsuring channel policy settings")
+print("\nEnsuring node-level channel policy settings")
 chans = json.loads(base.warcli("lncli 1 describegraph"))["edges"]
 for chan in chans:
     # node_1 or node_2 is tank 1 with its non-default --bitcoin.timelockdelta=20
@@ -71,6 +71,10 @@ def check_invoices():
         return False
 base.wait_for_predicate(check_invoices)
 
+print("\nEnsuring channel-level channel policy settings")
+payment = json.loads(base.warcli("lncli 0 listpayments"))["payments"][0]
+assert payment["fee_msat"] == "5503"
+
 print("\nEnsuring circuit breaker tracked payment")
 assert len(get_cb_forwards(1)["forwards"]) == 1