Add a GitHub App support for aiohttp implementation

browntruck/__init__.py

@@ -20,6 +20,7 @@
 from aiocron import crontab
 from aiohttp import web
 
+from browntruck.integration_installation import integration_installation_hook
 from browntruck.news import news_hook
 from browntruck.rebase import check_prs, needs_rebase_hook
 
@@ -37,18 +38,30 @@ async def _shutdown_redis_pool(app):
     await app["redis.pool"].wait_closed()
 
 
-def create_app(*, github_token, github_payload_key, repo, redis_url,
+def create_app(*, github_token, github_payload_key,
+               github_app_id,
+               github_app_private_key,
+               # github_app_webhook_secret,  # seems == github_payload_key
+               repo, redis_url,
                loop=None):
     app = web.Application(loop=loop)
     app["repo"] = repo
     app["github_token"] = github_token
     app["github_payload_key"] = github_payload_key
+    app["github_app_id"] = github_app_id
+    app["github_app_private_key"] = github_app_private_key
+    # app["github_app_webhook_secret"] = github_app_webhook_secret
     app["redis.url"] = redis_url
 
     app.on_startup.append(_create_redis_pool)
 
     app.on_cleanup.append(_shutdown_redis_pool)
 
+    app.router.add_post(
+        "/hooks/integration_installation",
+        integration_installation_hook,
+    )
+
     app.router.add_post("/hooks/news", news_hook)
     app.router.add_post("/hooks/rebase", needs_rebase_hook)
 
@@ -64,6 +77,11 @@ def main(argv):
     app = create_app(
         github_token=os.environ.get("GITHUB_TOKEN"),
         github_payload_key=os.environ.get("GITHUB_PAYLOAD_KEY"),
+        # GitHub App integration credentials:
+        github_app_id=os.environ.get("GITHUB_APP_IDENTIFIER"),
+        github_app_private_key=os.environ.get("GITHUB_PRIVATE_KEY"),
+        # github_app_webhook_secret=os.environ.get("GITHUB_WEBHOOK_SECRET"),  # seems to be the same as github_payload_key
+        # GitHub App integration credentials end
         repo=os.environ.get("REPO"),
         redis_url=os.environ.get("REDIS_URL"),
         loop=loop,

browntruck/integration_installation.py

@@ -0,0 +1,45 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import json
+
+import aiohttp
+import gidgethub.aiohttp
+
+from aiohttp import web
+
+from browntruck.utils import get_install_token
+
+
+async def integration_installation_hook(request):
+    payload = await request.read()
+
+    data = json.loads(payload.decode(request.charset or "utf8"))
+    installation_token = await get_install_token(
+	app_id=app["github_app_id"],
+	private_key=app["github_app_private_key"],
+	install_id=data["installation"]["id"],
+	payload=data,
+    )
+
+    async with aiohttp.ClientSession() as session:
+        gh = gidgethub.aiohttp.GitHubAPI(
+            session,
+            "BrownTruck-Bot"  # TODO: add "/1.0" as in version
+            " (+https://github.com/pypa/browntruck)",
+            oauth_token=request.app["github_token"],
+        )
+	# ...
+
+    return web.json_response({
+	"message": "installation recorded",
+    })

browntruck/utils.py

@@ -11,7 +11,11 @@
 # limitations under the License.
 
 import hmac
+import time
 
+import aiohttp
+import gidgethub.aiohttp
+import jwt
 
 class InvalidSignature(Exception):
     pass
@@ -22,3 +26,34 @@ def verify_signature(key, signature, body):
     if not hmac.compare_digest(f"sha1={digest.hexdigest().lower()}",
                                signature.lower()):
         raise InvalidSignature
+
+
+def get_gh_jwt(app_id, private_key):
+    """Create a signed JWT, valid for 60 seconds."""
+    now = int(time.time())
+    payload = {
+        "iat": now,
+        "exp": now + 60,
+        "iss": app_id
+    }
+    return jwt.encode(
+        payload,
+        key=private_key,
+        algorithm="RS256"
+    ).decode('utf-8')
+
+
+async def get_install_token(*, app_id, private_key, install_id, payload):
+    gh_jwt = get_gh_jwt(app_id, private_key)
+    async with aiohttp.ClientSession() as session:
+        gh = gidgethub.aiohttp.GitHubAPI(
+            session,
+            "BrownTruck-Bot"  # TODO: add "/1.0" as in version
+            " (+https://github.com/pypa/browntruck)",
+            jwt=gh_jwt,
+        )
+        return (
+            await gh.getitem(
+                payload["installation"]["access_tokens_url"]
+            )["token"]
+        )

requirements.txt

@@ -12,6 +12,7 @@ gidgethub==2.0.0
 hiredis==0.2.0
 multidict==2.1.4
 pycares==2.1.1
+pyjwt
 python-dateutil==2.6.0
 six==1.10.0
 unidiff==0.5.2+new.files