plugin:added invoice creation event

New invoice_creation event triggered when an new invoice is created

Changelog-Added: plugin: New invoice_creation plugin event

contrib/plugins/helloworld.py

@@ -48,6 +48,14 @@ def on_payment(plugin, invoice_payment, **kwargs):
                                           invoice_payment.get("msat")))
 
 
+@plugin.subscribe("invoice_creation")
+def on_invoice_creation(plugin, invoice_creation, **kwargs):
+    plugin.log("Received invoice_creation event for label {}, preimage {},"
+               " and amount of {}".format(invoice_creation.get("label"),
+                                          invoice_creation.get("preimage"),
+                                          invoice_creation.get("msat")))
+
+
 @plugin.hook("htlc_accepted")
 def on_htlc_accepted(onion, htlc, plugin, **kwargs):
     plugin.log('on_htlc_accepted called')

doc/PLUGINS.md

@@ -334,6 +334,20 @@ A notification for topic `invoice_payment` is sent every time an invoie is paid.
     "msat": "10000msat"
   }
 }
+
+```
+### `invoice_creation`
+
+A notification for topic `invoice_creation` is sent every time an invoie is paid.
+
+```json
+{
+  "invoice_creation": {
+    "label": "unique-label-for-invoice",
+    "preimage": "0000000000000000000000000000000000000000000000000000000000000000",
+    "msat": "10000msat"
+  }
+}
 ```
 
 ### `warning`

lightningd/invoice.c

@@ -720,6 +720,8 @@ static void gossipd_incoming_channels_reply(struct subd *gossipd,
 	json_add_u64(response, "expires_at", details->expiry_time);
 	json_add_string(response, "bolt11", details->bolt11);
 
+	notify_invoice_creation(info->cmd->ld, *info->b11->msat, info->payment_preimage, info->label);
+
 	/* Warn if there's not sufficient incoming capacity. */
 	if (tal_count(info->b11->routes) == 0) {
 		log_unusual(info->cmd->ld->log,

lightningd/notification.c

@@ -140,6 +140,37 @@ void notify_invoice_payment(struct lightningd *ld, struct amount_msat amount,
 	plugins_notify(ld->plugins, take(n));
 }
 
+static void invoice_creation_notification_serialize(struct json_stream *stream,
+						   struct amount_msat amount,
+						   struct preimage preimage,
+						   const struct json_escape *label)
+{
+	json_object_start(stream, "invoice_creation");
+	json_add_string(stream, "msat",
+			type_to_string(tmpctx, struct amount_msat, &amount));
+	json_add_hex(stream, "preimage", &preimage, sizeof(preimage));
+	json_add_escaped_string(stream, "label", label);
+	json_object_end(stream);
+}
+
+REGISTER_NOTIFICATION(invoice_creation,
+		      invoice_creation_notification_serialize)
+
+void notify_invoice_creation(struct lightningd *ld, struct amount_msat amount,
+			    struct preimage preimage, const struct json_escape *label)
+{
+	void (*serialize)(struct json_stream *,
+			  struct amount_msat,
+			  struct preimage,
+			  const struct json_escape *) = invoice_creation_notification_gen.serialize;
+
+	struct jsonrpc_notification *n
+		= jsonrpc_notification_start(NULL, invoice_creation_notification_gen.topic);
+	serialize(n->stream, amount, preimage, label);
+	jsonrpc_notification_end(n);
+	plugins_notify(ld->plugins, take(n));
+}
+
 static void channel_opened_notification_serialize(struct json_stream *stream,
 						  struct node_id *node_id,
 						  struct amount_sat *funding_sat,

lightningd/notification.h

@@ -47,6 +47,9 @@ void notify_warning(struct lightningd *ld, struct log_entry *l);
 void notify_invoice_payment(struct lightningd *ld, struct amount_msat amount,
 			    struct preimage preimage, const struct json_escape *label);
 
+void notify_invoice_creation(struct lightningd *ld, struct amount_msat amount,
+			    struct preimage preimage, const struct json_escape *label);
+
 void notify_channel_opened(struct lightningd *ld, struct node_id *node_id,
 			   struct amount_sat *funding_sat, struct bitcoin_txid *funding_txid,
 			   bool *funding_locked);

lightningd/test/run-invoice-select-inchan.c

@@ -246,6 +246,10 @@ void notify_connect(struct lightningd *ld UNNEEDED, struct node_id *nodeid UNNEE
 /* Generated stub for notify_disconnect */
 void notify_disconnect(struct lightningd *ld UNNEEDED, struct node_id *nodeid UNNEEDED)
 { fprintf(stderr, "notify_disconnect called!\n"); abort(); }
+/* Generated stub for notify_invoice_creation */
+void notify_invoice_creation(struct lightningd *ld UNNEEDED, struct amount_msat amount UNNEEDED,
+			    struct preimage preimage UNNEEDED, const struct json_escape *label UNNEEDED)
+{ fprintf(stderr, "notify_invoice_creation called!\n"); abort(); }
 /* Generated stub for notify_invoice_payment */
 void notify_invoice_payment(struct lightningd *ld UNNEEDED, struct amount_msat amount UNNEEDED,
 			    struct preimage preimage UNNEEDED, const struct json_escape *label UNNEEDED)

tests/test_plugin.py

@@ -694,6 +694,24 @@ def test_invoice_payment_notification(node_factory):
                            .format(label, preimage, msats))
 
 
+@unittest.skipIf(not DEVELOPER, "needs to deactivate shadow routing")
+def test_invoice_creation_notification(node_factory):
+    """
+    Test the 'invoice_creation' notification
+    """
+    opts = [{}, {"plugin": os.path.join(os.getcwd(), "contrib/plugins/helloworld.py")}]
+    l1, l2 = node_factory.line_graph(2, opts=opts)
+
+    msats = 12345
+    preimage = '1' * 64
+    label = "a_descriptive_label"
+    l2.rpc.invoice(msats, label, 'description', preimage=preimage)
+
+    l2.daemon.wait_for_log(r"Received invoice_creation event for label {},"
+                           " preimage {}, and amount of {}msat"
+                           .format(label, preimage, msats))
+
+
 def test_channel_opened_notification(node_factory):
     """
     Test the 'channel_opened' notification sent at channel funding success.