Merge DNS changes and adjustments to automated restic backup on teal from dev branch

devices/teal/config/etc/systemd/system/restic-backup@.service

@@ -0,0 +1,17 @@
+[Unit]
+Description=Backup with restic to Backblaze B2
+# Email on failure require special setup. See README.md
+#OnFailure=status-email-user@%n.service
+# Prevent backup on unmetered connection. Needs special setup. See README.md.
+#Requires=nm-unmetered-connection.service
+#After=nm-unmetered-connection.service
+
+[Service]
+Type=simple
+Nice=10
+# $HOME or $XDG_CACHE_HOME must be set for restic to find /root/.cache/restic/
+Environment="HOME=/root"
+# pipefail: so that redirecting stderr from the script to systemd-cat does not hide the failed command from OnFailure above.
+# Random sleep (in seconds): in the case of multiple backup profiles. Many restic instances started at the same time could case high load or network bandwith usage.
+# `systemd-cat` allows showing the restic output to the systemd journal
+ExecStart=/bin/bash -c 'set -o pipefail; ps cax | grep -q restic && sleep $(shuf -i 0-300 -n 1); source /etc/restic/%I.env.sh && /bin/restic_backup.sh 2>&1 | systemd-cat'