notify: channel_state_changed now receives notice when channel opens

Previously we wouldn't notify when a channel moves into state
"CHANNELD_AWAITING_LOCKIN", as this is the original state (so there's
no movement btw states). This meant that it's impossible to track when a
channel's commitment txs have been exchanged and we're waiting for
onchain confirmation.

It's useful to have notice of this initialization though, all in one
place so that the `channel_state_changed` notification can successfully
track the entire lifecycle of a channel, from inception to close.

Note that for v2 "dual-funded" channels, we already notify at the same place, at
"DUALOPEND_AWAITING_LOCKIN" (the initial state for a dualopend channel
is "DUALOPEND_OPEN_INIT" -- this is the only state we don't get notified
at now...)

Changelog-Added: Plugins: `channel_state_changed` now triggers for a v1 channel's initial "CHANNELD_AWAITING_LOCKIN" state transition (from prior state "unknown")

lightningd/opening_control.c

@@ -102,6 +102,7 @@ wallet_commit_channel(struct lightningd *ld,
 	u64 static_remotekey_start;
 	u32 lease_start_blockheight = 0; /* No leases on v1 */
 	struct short_channel_id *alias_local;
+	struct timeabs timestamp;
 
 	/* We cannot both be the fundee *and* have a `fundchannel_start`
 	 * command running!
@@ -226,6 +227,17 @@ wallet_commit_channel(struct lightningd *ld,
 	/* Now we finally put it in the database. */
 	wallet_channel_insert(ld->wallet, channel);
 
+	/* Notify that channel state changed (from non existant to existant) */
+	timestamp = time_now();
+	notify_channel_state_changed(ld, &channel->peer->id,
+				     &channel->cid,
+				     channel->scid, /* NULL */
+				     &timestamp,
+				     0, /* No prior state */
+				     channel->state,
+				     channel->state_change_cause,
+				     "new channel opened");
+
 	return channel;
 }
 

tests/test_plugin.py

@@ -777,27 +777,29 @@ def test_channel_state_changed_bilateral(node_factory, bitcoind):
 
     event1 = wait_for_event(l1)
     event2 = wait_for_event(l2)
-    if l1.config('experimental-dual-fund'):
-        # Dual funded channels have an extra state change
-        assert(event1['peer_id'] == l2_id)  # we only test these IDs the first time
-        assert(event1['channel_id'] == cid)
-        assert(event1['short_channel_id'] is None)
-        assert(event1['old_state'] == "DUALOPEND_OPEN_INIT")
-        assert(event1['new_state'] == "DUALOPEND_AWAITING_LOCKIN")
-        assert(event1['cause'] == "user")
-        assert(event1['message'] == "Sigs exchanged, waiting for lock-in")
-        event1 = wait_for_event(l1)
-        assert(event2['peer_id'] == l1_id)  # we only test these IDs the first time
-        assert(event2['channel_id'] == cid)
-        assert(event2['short_channel_id'] is None)
-        assert(event2['old_state'] == "DUALOPEND_OPEN_INIT")
-        assert(event2['new_state'] == "DUALOPEND_AWAITING_LOCKIN")
-        assert(event2['cause'] == "remote")
-        assert(event2['message'] == "Sigs exchanged, waiting for lock-in")
-        event2 = wait_for_event(l2)
-
     assert(event1['peer_id'] == l2_id)  # we only test these IDs the first time
     assert(event1['channel_id'] == cid)
+    assert(event1['short_channel_id'] is None)  # None until locked in
+    assert(event1['cause'] == "user")
+
+    assert(event2['peer_id'] == l1_id)  # we only test these IDs the first time
+    assert(event2['channel_id'] == cid)
+    assert(event2['short_channel_id'] is None)  # None until locked in
+    assert(event2['cause'] == "remote")
+
+    for ev in [event1, event2]:
+        # Dual funded channels
+        if l1.config('experimental-dual-fund'):
+            assert(ev['old_state'] == "DUALOPEND_OPEN_INIT")
+            assert(ev['new_state'] == "DUALOPEND_AWAITING_LOCKIN")
+            assert(ev['message'] == "Sigs exchanged, waiting for lock-in")
+        else:
+            assert(ev['old_state'] == "unknown")
+            assert(ev['new_state'] == "CHANNELD_AWAITING_LOCKIN")
+            assert(ev['message'] == "new channel opened")
+
+    event1 = wait_for_event(l1)
+    event2 = wait_for_event(l2)
     assert(event1['short_channel_id'] == scid)
     if l1.config('experimental-dual-fund'):
         assert(event1['old_state'] == "DUALOPEND_AWAITING_LOCKIN")
@@ -807,8 +809,6 @@ def test_channel_state_changed_bilateral(node_factory, bitcoind):
     assert(event1['cause'] == "user")
     assert(event1['message'] == "Lockin complete")
 
-    assert(event2['peer_id'] == l1_id)
-    assert(event2['channel_id'] == cid)
     assert(event2['short_channel_id'] == scid)
     if l1.config('experimental-dual-fund'):
         assert(event2['old_state'] == "DUALOPEND_AWAITING_LOCKIN")
@@ -911,18 +911,21 @@ def test_channel_state_changed_unilateral(node_factory, bitcoind):
         return event
 
     event2 = wait_for_event(l2)
+    assert(event2['peer_id'] == l1_id)
+    assert(event2['channel_id'] == cid)
+    assert(event2['short_channel_id'] is None)
+    assert(event2['cause'] == "remote")
+
     if l2.config('experimental-dual-fund'):
-        assert(event2['peer_id'] == l1_id)
-        assert(event2['channel_id'] == cid)
-        assert(event2['short_channel_id'] is None)
         assert(event2['old_state'] == "DUALOPEND_OPEN_INIT")
         assert(event2['new_state'] == "DUALOPEND_AWAITING_LOCKIN")
-        assert(event2['cause'] == "remote")
         assert(event2['message'] == "Sigs exchanged, waiting for lock-in")
-        event2 = wait_for_event(l2)
+    else:
+        assert(event2['old_state'] == "unknown")
+        assert(event2['new_state'] == "CHANNELD_AWAITING_LOCKIN")
+        assert(event2['message'] == "new channel opened")
 
-    assert(event2['peer_id'] == l1_id)  # we only test these IDs the first time
+    event2 = wait_for_event(l2)
-    assert(event2['channel_id'] == cid)
     assert(event2['short_channel_id'] == scid)
     if l2.config('experimental-dual-fund'):
         assert(event2['old_state'] == "DUALOPEND_AWAITING_LOCKIN")