From 4e2a1c3e52183445a9d927b8d52bb2eb21b532ee Mon Sep 17 00:00:00 2001
From: "Joshua M. Boniface" <joshua@boniface.me>
Date: Mon, 28 Jun 2021 12:18:48 -0400
Subject: [PATCH] Add worker wrapper to fix Deb incompatibility

Celery 5.x introduced a new worker argument format that is not
backwards-compatible with the older Celery 4.x format. This created a
conundrum since we use one service unit for both Debian 10 (4.x) and
Debian 11 (5.x). Instead of worse hacks, create a wrapper script to
start the worker with the correct arguments instead.
---
 api-daemon/pvcapid-worker.service |  2 +-
 api-daemon/pvcapid-worker.sh      | 40 +++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100755 api-daemon/pvcapid-worker.sh

diff --git a/api-daemon/pvcapid-worker.service b/api-daemon/pvcapid-worker.service
index 58adcf43..f79f58f5 100644
--- a/api-daemon/pvcapid-worker.service
+++ b/api-daemon/pvcapid-worker.service
@@ -9,7 +9,7 @@ Type = simple
 WorkingDirectory = /usr/share/pvc
 Environment = PYTHONUNBUFFERED=true
 Environment = PVC_CONFIG_FILE=/etc/pvc/pvcapid.yaml
-ExecStart = /usr/bin/celery --app pvcapid.flaskapi.celery worker --concurrency 1 --loglevel INFO
+ExecStart = /usr/share/pvc/pvcapid-worker.sh
 Restart = on-failure
 
 [Install]
diff --git a/api-daemon/pvcapid-worker.sh b/api-daemon/pvcapid-worker.sh
new file mode 100755
index 00000000..9ff5505e
--- /dev/null
+++ b/api-daemon/pvcapid-worker.sh
@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+
+# pvcapid-worker.py - API Celery worker daemon startup stub
+# Part of the Parallel Virtual Cluster (PVC) system
+#
+#    Copyright (C) 2018-2021 Joshua M. Boniface <joshua@boniface.me>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation, version 3.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+#
+###############################################################################
+
+CELERY_BIN="$( which celery )"
+
+# This absolute hackery is needed because Celery got the bright idea to change how their
+# app arguments work in a non-backwards-compatible way with Celery 5.
+case "$( cat /etc/debian_version )" in
+    10.*)
+        CELERY_ARGS="worker --app pvcapid.flaskapi.celery --concurrency 1 --loglevel INFO"
+    ;;
+    11.*)
+        CELERY_ARGS="--app pvcapid.flaskapi.celery worker --concurrency 1 --loglevel INFO"
+    ;;
+    *)
+        echo "Invalid Debian version found!"
+        exit 1
+    ;;
+esac
+
+${CELERY_BIN} ${CELERY_ARGS}
+exit $?