notifier: adding basic oncall notifications (envoyproxy#29820)

Since slack google calendar support is deprecated, adding it back in via the PR notifier.
(theoretically) notifying general and oncall of rotation switches. This won't work (but will post that it doesn't work) if we do overrides incorrectly.
Signed-off-by: Alyssa Wilk <[email protected]>

.github/actions/pr_notifier/pr_notifier.py

@@ -17,7 +17,9 @@
 import os
 import sys
 
+import requests
 import github
+import icalendar
 from slack_sdk import WebClient
 from slack_sdk.errors import SlackApiError
 
@@ -43,6 +45,9 @@
     'soulxu': 'U01GNQ3B8AY',
 }
 
+# Oncall calendar
+CALENDAR = "https://calendar.google.com/calendar/ical/d6glc0l5rc3v235q9l2j29dgovh3dn48%40import.calendar.google.com/public/basic.ics"
+
 # First pass reviewers who are not maintainers should get
 # notifications but not result in a PR not getting assigned a
 # maintainer owner.
@@ -226,10 +231,30 @@ def post_to_oncall(client, unassigned_prs, out_slo_prs):
             text=(
                 "*Untriaged Issues* (please tag and cc area experts)\n<%s|%s>" %
                 (issue_link, issue_link)))
+        # On Monday, post the new oncall.
+        if datetime.date.today().weekday() == 0:
+            oncall = parse_calendar()
+            client.chat_postMessage(channel='#envoy-maintainer-oncall', text=(oncall))
+            client.chat_postMessage(channel='#general', text=(oncall))
     except SlackApiError as e:
         print("Unexpected error %s", e.response["error"])
 
 
+def parse_calendar():
+    ical = requests.get(CALENDAR)
+    parsed_calendar = icalendar.Calendar.from_ical(ical.text)
+    ical.close()
+
+    now = datetime.datetime.now()
+    sunday = now - datetime.timedelta(days=now.weekday() + 1)
+
+    for component in parsed_calendar.walk():
+        if component.name == "VEVENT":
+            if (sunday.date() == component.decoded("dtstart").date()):
+                return component.get("summary")
+    return "unable to find this week's oncall"
+
+
 if __name__ == '__main__':
     parser = argparse.ArgumentParser()
     parser.add_argument(

.github/actions/pr_notifier/requirements.in

@@ -1,2 +1,4 @@
 pygithub
 slack_sdk
+requests
+icalendar

.github/actions/pr_notifier/requirements.txt

@@ -1,8 +1,8 @@
 #
-# This file is autogenerated by pip-compile
-# To update, run:
+# This file is autogenerated by pip-compile with Python 3.11
+# by the following command:
 #
-#    pip-compile --generate-hashes .github/actions/pr_notifier/requirements.txt
+#    pip-compile --allow-unsafe --generate-hashes requirements.in
 #
 certifi==2023.7.22 \
     --hash=sha256:539cc1d13202e33ca466e88b2807e29f4c13049d6d87031a3c110744495cb082 \
@@ -167,6 +167,10 @@ deprecated==1.2.13 \
     --hash=sha256:43ac5335da90c31c24ba028af536a91d41d53f9e6901ddb021bcc572ce44e38d \
     --hash=sha256:64756e3e14c8c5eea9795d93c524551432a0be75629f8f29e67ab8caf076c76d
     # via pygithub
+icalendar==5.0.10 \
+    --hash=sha256:34f0ca020b804758ddf316eb70d1d46f769bce64638d5a080cb65dd46cfee642 \
+    --hash=sha256:6e392c2f301b6b5f49433e14c905db3de444b12876f3345f1856a75e9cd8be6f
+    # via -r requirements.in
 idna==2.10 \
     --hash=sha256:b307872f855b18632ce0c21c5e45be78c0ea7ae4c15c828c20788b26921eb3f6 \
     --hash=sha256:b97d804b1e9b523befed77c48dacec60e6dcb0b5391d57af6a65a312a90648c0
@@ -207,10 +211,16 @@ python-dateutil==2.8.2 \
     --hash=sha256:0123cacc1627ae19ddf3c27a5de5bd67ee4586fbdd6440d9748f8abb483d3e86 \
     --hash=sha256:961d03dc3453ebbc59dbdea9e4e11c5651520a876d0f4db161e8674aae935da9
     # via pygithub
+pytz==2023.3.post1 \
+    --hash=sha256:7b4fddbeb94a1eba4b557da24f19fdf9db575192544270a9101d8509f9f43d7b \
+    --hash=sha256:ce42d816b81b68506614c11e8937d3aa9e41007ceb50bfdcb0749b921bf646c7
+    # via icalendar
 requests==2.31.0 \
     --hash=sha256:58cd2187c01e70e6e26505bca751777aa9f2ee0b7f4300988b709f44e013003f \
     --hash=sha256:942c5a758f98d790eaed1a29cb6eefc7ffb0d1cf7af05c3d2791656dbd6ad1e1
-    # via pygithub
+    # via
+    #   -r requirements.in
+    #   pygithub
 six==1.16.0 \
     --hash=sha256:1e61c37477a1626458e36f7b1d82aa5c9b094fa4802892072e49de9c60c4c926 \
     --hash=sha256:8abb2f1d86890a2dfb989f9a77cfcfd3e47c2a354b01111771326f8aa26e0254