From db5970ac6d7843e7bd7e50638e0d999ed8018e37 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <clokep@users.noreply.github.com>
Date: Mon, 3 Aug 2020 07:09:33 -0400
Subject: [PATCH] Convert ACME code to async/await. (#7989)

---
 changelog.d/7989.misc     |  1 +
 synapse/app/homeserver.py | 13 ++++++-------
 synapse/handlers/acme.py  | 11 ++++-------
 3 files changed, 11 insertions(+), 14 deletions(-)
 create mode 100644 changelog.d/7989.misc

diff --git a/changelog.d/7989.misc b/changelog.d/7989.misc
new file mode 100644
index 000000000..dfe4c0317
--- /dev/null
+++ b/changelog.d/7989.misc
@@ -0,0 +1 @@
+Convert various parts of the codebase to async/await.
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index ec7401f91..b011e00b4 100644
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -380,13 +380,12 @@ def setup(config_options):
 
     hs.setup_master()
 
-    @defer.inlineCallbacks
-    def do_acme():
+    async def do_acme() -> bool:
         """
         Reprovision an ACME certificate, if it's required.
 
         Returns:
-            Deferred[bool]: Whether the cert has been updated.
+            Whether the cert has been updated.
         """
         acme = hs.get_acme_handler()
 
@@ -405,7 +404,7 @@ def setup(config_options):
             provision = True
 
         if provision:
-            yield acme.provision_certificate()
+            await acme.provision_certificate()
 
         return provision
 
@@ -415,7 +414,7 @@ def setup(config_options):
         Provision a certificate from ACME, if required, and reload the TLS
         certificate if it's renewed.
         """
-        reprovisioned = yield do_acme()
+        reprovisioned = yield defer.ensureDeferred(do_acme())
         if reprovisioned:
             _base.refresh_certificate(hs)
 
@@ -427,8 +426,8 @@ def setup(config_options):
                 acme = hs.get_acme_handler()
                 # Start up the webservices which we will respond to ACME
                 # challenges with, and then provision.
-                yield acme.start_listening()
-                yield do_acme()
+                yield defer.ensureDeferred(acme.start_listening())
+                yield defer.ensureDeferred(do_acme())
 
                 # Check if it needs to be reprovisioned every day.
                 hs.get_clock().looping_call(reprovision_acme, 24 * 60 * 60 * 1000)
diff --git a/synapse/handlers/acme.py b/synapse/handlers/acme.py
index a2d7959ab..7666d3abc 100644
--- a/synapse/handlers/acme.py
+++ b/synapse/handlers/acme.py
@@ -17,7 +17,6 @@ import logging
 
 import twisted
 import twisted.internet.error
-from twisted.internet import defer
 from twisted.web import server, static
 from twisted.web.resource import Resource
 
@@ -41,8 +40,7 @@ class AcmeHandler(object):
         self.reactor = hs.get_reactor()
         self._acme_domain = hs.config.acme_domain
 
-    @defer.inlineCallbacks
-    def start_listening(self):
+    async def start_listening(self):
         from synapse.handlers import acme_issuing_service
 
         # Configure logging for txacme, if you need to debug
@@ -82,18 +80,17 @@ class AcmeHandler(object):
         self._issuer._registered = False
 
         try:
-            yield self._issuer._ensure_registered()
+            await self._issuer._ensure_registered()
         except Exception:
             logger.error(ACME_REGISTER_FAIL_ERROR)
             raise
 
-    @defer.inlineCallbacks
-    def provision_certificate(self):
+    async def provision_certificate(self):
 
         logger.warning("Reprovisioning %s", self._acme_domain)
 
         try:
-            yield self._issuer.issue_cert(self._acme_domain)
+            await self._issuer.issue_cert(self._acme_domain)
         except Exception:
             logger.exception("Fail!")
             raise