fix: pay_invoice timeout to prevent blocking (#2875)

* fix: make invoice non blocking

* fix with vlad

* wallet.js take pending into account

* fixup!

* add check payment to outgoing

* revert

* bundle

* fix: label

* fix: rebase change

* feat: configure pay invoice wait time

* fix: check payment button

* bundle

* fix: task in async context

---------

Co-authored-by: Vlad Stan <stan.v.vlad@gmail.com>

lnbits/core/services/payments.py

@@ -1,3 +1,4 @@
+import asyncio
 import json
 import time
 from datetime import datetime, timedelta, timezone
@@ -17,6 +18,7 @@ from lnbits.db import Connection, Filters
 from lnbits.decorators import check_user_extension_access
 from lnbits.exceptions import InvoiceError, PaymentError
 from lnbits.settings import settings
+from lnbits.tasks import create_task
 from lnbits.utils.crypto import fake_privkey, random_secret_and_hash
 from lnbits.utils.exchange_rates import fiat_amount_as_satoshis, satoshis_amount_as_fiat
 from lnbits.wallets import fake_wallet, get_funding_source
@@ -61,11 +63,11 @@ async def pay_invoice(
     invoice = _validate_payment_request(payment_request, max_sat)
     assert invoice.amount_msat
 
-    async with db.reuse_conn(conn) if conn else db.connect() as conn:
+    async with db.reuse_conn(conn) if conn else db.connect() as new_conn:
         amount_msat = invoice.amount_msat
-        wallet = await _check_wallet_for_payment(wallet_id, tag, amount_msat, conn)
+        wallet = await _check_wallet_for_payment(wallet_id, tag, amount_msat, new_conn)
 
-        if await is_internal_status_success(invoice.payment_hash, conn):
+        if await is_internal_status_success(invoice.payment_hash, new_conn):
             raise PaymentError("Internal invoice already paid.", status="failed")
 
         _, extra = await calculate_fiat_amounts(amount_msat / 1000, wallet, extra=extra)
@@ -80,8 +82,10 @@ async def pay_invoice(
             extra=extra,
         )
 
-        payment = await _pay_invoice(wallet, create_payment_model, conn)
-        await _credit_service_fee_wallet(payment, conn)
+    payment = await _pay_invoice(wallet, create_payment_model, conn)
+
+    async with db.reuse_conn(conn) if conn else db.connect() as new_conn:
+        await _credit_service_fee_wallet(payment, new_conn)
 
         return payment
 
@@ -580,13 +584,19 @@ async def _pay_external_invoice(
     fee_reserve_msat = fee_reserve(amount_msat, internal=False)
     service_fee_msat = service_fee(amount_msat, internal=False)
 
-    funding_source = get_funding_source()
-
-    logger.debug(f"fundingsource: sending payment {checking_id}")
-    payment_response: PaymentResponse = await funding_source.pay_invoice(
-        create_payment_model.bolt11, fee_reserve_msat
+    task = create_task(
+        _fundingsource_pay_invoice(checking_id, payment.bolt11, fee_reserve_msat)
     )
-    logger.debug(f"backend: pay_invoice finished {checking_id}, {payment_response}")
+
+    # make sure a hold invoice or deferred payment is not blocking the server
+    try:
+        wait_time = max(1, settings.lnbits_funding_source_pay_invoice_wait_seconds)
+        payment_response = await asyncio.wait_for(task, wait_time)
+    except asyncio.TimeoutError:
+        # return pending payment on timeout
+        logger.debug(f"payment timeout, {checking_id} is still pending")
+        return payment
+
     if payment_response.checking_id and payment_response.checking_id != checking_id:
         logger.warning(
             f"backend sent unexpected checking_id (expected: {checking_id} got:"
@@ -622,9 +632,22 @@ async def _pay_external_invoice(
             "didn't receive checking_id from backend, payment may be stuck in"
             f" database: {checking_id}"
         )
+
     return payment
 
 
+async def _fundingsource_pay_invoice(
+    checking_id: str, bolt11: str, fee_reserve_msat: int
+) -> PaymentResponse:
+    logger.debug(f"fundingsource: sending payment {checking_id}")
+    funding_source = get_funding_source()
+    payment_response: PaymentResponse = await funding_source.pay_invoice(
+        bolt11, fee_reserve_msat
+    )
+    logger.debug(f"backend: pay_invoice finished {checking_id}, {payment_response}")
+    return payment_response
+
+
 async def _verify_external_payment(
     payment: Payment, conn: Optional[Connection] = None
 ) -> Payment:

lnbits/core/templates/admin/_tab_funding.html

@@ -54,7 +54,29 @@
         </div>
       </div>
       <div class="row q-col-gutter-md">
-        <div class="col-12 col-md-4">
+        <div class="col-12 col-md-3">
+          <p><span v-text="$t('fee_reserve')"></span></p>
+
+          <q-input
+            type="number"
+            filled
+            v-model="formData.lnbits_reserve_fee_min"
+            :label="$t('fee_reserve_msats')"
+          >
+          </q-input>
+        </div>
+        <div class="col-12 col-md-3">
+          <p><span v-text="$t('fee_reserve_percent')"></span></p>
+          <q-input
+            type="number"
+            filled
+            name="lnbits_reserve_fee_percent"
+            v-model="formData.lnbits_reserve_fee_percent"
+            :label="$t('reserve_fee_in_percent')"
+            step="0.1"
+          ></q-input>
+        </div>
+        <div class="col-12 col-md-3">
           <p><span v-text="$t('invoice_expiry')"></span></p>
           <q-input
             filled
@@ -65,29 +87,18 @@
           >
           </q-input>
         </div>
-        <div class="col-12 col-md-8">
-          <p><span v-text="$t('fee_reserve')"></span></p>
-          <div class="row q-col-gutter-md">
-            <div class="col-6">
-              <q-input
-                type="number"
-                filled
-                v-model="formData.lnbits_reserve_fee_min"
-                :label="$t('fee_reserve_msats')"
-              >
-              </q-input>
-            </div>
-            <div class="col-6">
-              <q-input
-                type="number"
-                filled
-                name="lnbits_reserve_fee_percent"
-                v-model="formData.lnbits_reserve_fee_percent"
-                :label="$t('fee_reserve_percent')"
-                step="0.1"
-              ></q-input>
-            </div>
-          </div>
+        <div class="col-12 col-md-3">
+          <p><span v-text="$t('payment_wait_time')"></span></p>
+          <q-input
+            type="number"
+            filled
+            name="lnbits_funding_source_pay_invoice_wait_seconds"
+            v-model="formData.lnbits_funding_source_pay_invoice_wait_seconds"
+            :label="$t('payment_wait_time')"
+            :hint="$t('payment_wait_time_desc')"
+            step="1"
+            min="0"
+          ></q-input>
         </div>
       </div>
       <div v-if="isSuperUser">