From 1d52a49f5c8158b1336f8271a6ea8afb39396d07 Mon Sep 17 00:00:00 2001
From: Jakub Czajka <jakub@ekhem.eu.org>
Date: Wed, 29 Nov 2023 23:57:04 +0100
Subject: [PATCH] Implement a service to notify about failures with an email.

---
 notify_failure@.service | 16 ++++++++++++++++
 notify_on_failure.sh    | 19 +++++++++++++++++++
 2 files changed, 35 insertions(+)
 create mode 100644 notify_failure@.service
 create mode 100755 notify_on_failure.sh

diff --git a/notify_failure@.service b/notify_failure@.service
new file mode 100644
index 0000000..4a67097
--- /dev/null
+++ b/notify_failure@.service
@@ -0,0 +1,16 @@
+# Copyright (c) 2023 Jakub Czajka <jakub@ekhem.eu.org>
+# License: GPL-3.0 or later.
+
+[Unit]
+Description=Notify about failure through an email notification.
+
+[Service]
+Type=oneshot
+ExecStartPre=/usr/bin/git \
+    --work-tree=/tmp \
+    --git-dir=/srv/git/cron.git \
+    checkout main --force notify_on_failure.sh
+ExecStart=/tmp/notify_on_failure.sh %I
+
+[Install]
+WantedBy=multi-user.target
diff --git a/notify_on_failure.sh b/notify_on_failure.sh
new file mode 100755
index 0000000..2043dc7
--- /dev/null
+++ b/notify_on_failure.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+# Copyright (c) 2023 Jakub Czajka <jakub@ekhem.eu.org>
+# License: GPL-3.0 or later.
+
+MAILTO="server@${private_domain}"
+MAILFROM="server@${private_domain}"
+UNIT=${1}
+
+/usr/sbin/sendmail ${MAILTO} <<EOF
+From:${MAILFROM}
+To:${MAILTO}
+Subject:Status mail for unit: ${UNIT}
+
+$(journalctl --unit=${UNIT} \
+             --since="10 minute ago" \
+             --output=short-iso \
+             --no-hostname \
+             --no-pager)
+EOF
-- 
2.39.5