This repository has no description
services.flix: stop transmission and alert on Matrix when disk is low
When /var/download drops below 100 GiB free the guard now stops all
transmission torrents (it has no native low-disk pause like sabnzbd's
download_free) and posts a Matrix message to !MRjkvAaFPsjdYCpeiZ:lassul.us
via the archiver bot's access token. Torrents are restarted and a
recovery message sent once space climbs back above the threshold. State
is tracked in StateDirectory so alerts fire only on transitions, not
every run.
Assisted-by: Claude Code (claude-opus-4-8)
author
lassulus
date
(Jun 16, 2026, 4:53 PM CEST)
commit
34d29fb8
34d29fb8c2ae5cfc7e90933fa82dc1d7b30dbaaa
parent
1c1200ad
1c1200ad9c14e66c20e4290e0250972c3c3f2622
+38
-13
+38
-13
2configs/services/flix/default.nix
+38
-13
2configs/services/flix/default.nix
···
143
143
# pause downloads when /var/download runs low, so a full disk can no longer
144
144
# hard-wedge sabnzbd with an unrecoverable "Disk full! Forcing Pause".
145
145
# sabnzbd pauses itself once free disk drops below download_free/complete_free
146
-
# (auto-resuming above); this guard keeps those set to THRESH GiB and, since
147
-
# transmission has no equivalent, throttles its downloads below the threshold.
146
+
# (auto-resuming above); this guard keeps those set to THRESH GiB. Transmission
147
+
# has no equivalent, so below the threshold the guard stops all its torrents
148
+
# (restarting them on recovery) and posts a Matrix alert on each transition.
148
149
systemd.services.download-space-guard = {
149
150
wantedBy = [ "multi-user.target" ];
150
151
after = [ "sabnzbd.service" ];
···
154
155
pkgs.coreutils
155
156
pkgs.gnugrep
156
157
pkgs.gawk
158
+
pkgs.jq
157
159
pkgs.transmission_4
158
160
];
159
161
script = ''
160
162
set -efu
161
163
DIR=/var/download
162
164
THRESH=100
165
+
# !MRjkvAaFPsjdYCpeiZ:lassul.us, URL-encoded for the API path
166
+
ROOM=%21MRjkvAaFPsjdYCpeiZ%3Alassul.us
167
+
STATE="$STATE_DIRECTORY/state"
163
168
164
169
avail=$(df -Pk "$DIR" | awk 'NR==2 {print int($4 / 1024 / 1024)}')
165
170
···
167
172
key=$(grep -E '^api_key' "$INI" | head -1 | cut -d= -f2 | tr -d ' ')
168
173
sab() {
169
174
curl -fsS --max-time 15 "http://127.0.0.1:8080/api?output=json&apikey=$key&$1" >/dev/null || :
175
+
}
176
+
tr_remote() {
177
+
transmission-remote 128.0.0.1:9091 "$@" >/dev/null || :
178
+
}
179
+
notify() {
180
+
token=$(cat "$CREDENTIALS_DIRECTORY/matrix-token")
181
+
body=$(jq -nc --arg b "$1" '{msgtype: "m.text", body: $b}')
182
+
curl -fsS --max-time 15 -X POST \
183
+
-H "Authorization: Bearer $token" -H 'Content-Type: application/json' \
184
+
"https://matrix.lassul.us/_matrix/client/v3/rooms/$ROOM/send/m.room.message" \
185
+
--data "$body" >/dev/null || :
170
186
}
171
187
172
188
# sabnzbd pauses continuously once free disk drops below these (and
···
176
192
|| sab "mode=set_config§ion=misc&keyword=$k&value=''${THRESH}G"
177
193
done
178
194
179
-
# transmission has no built-in low-disk guard: throttle its downloads to a
180
-
# trickle below the threshold (seeding keeps running), lift it above.
181
-
tr_remote() {
182
-
transmission-remote 128.0.0.1:9091 "$@" >/dev/null || :
183
-
}
184
-
if [ "$avail" -lt "$THRESH" ]; then
185
-
echo "free ''${avail}G < ''${THRESH}G: sabnzbd paused by download_free, throttling transmission"
186
-
tr_remote -d 1
187
-
else
188
-
echo "free ''${avail}G >= ''${THRESH}G: downloads unrestricted"
189
-
tr_remote -D
195
+
prev=ok
196
+
if [ -f "$STATE" ]; then prev=$(cat "$STATE"); fi
197
+
if [ "$avail" -lt "$THRESH" ]; then cur=low; else cur=ok; fi
198
+
199
+
if [ "$cur" = low ]; then
200
+
# stop everything each run so newly-grabbed torrents can't fill the disk
201
+
tr_remote -t all --stop
202
+
if [ "$prev" != low ]; then
203
+
echo "free ''${avail}G < ''${THRESH}G: stopped transmission, alerting"
204
+
notify "⚠️ yellow: /var/download down to ''${avail} GiB free (< ''${THRESH} GiB). Stopped all transmission torrents; sabnzbd auto-paused via download_free."
205
+
fi
206
+
elif [ "$prev" = low ]; then
207
+
echo "free ''${avail}G >= ''${THRESH}G: resumed transmission, alerting"
208
+
tr_remote -t all --start
209
+
notify "✅ yellow: /var/download recovered to ''${avail} GiB free. Restarted transmission torrents."
190
210
fi
211
+
echo "$cur" > "$STATE"
191
212
'';
192
213
serviceConfig = {
193
214
Type = "oneshot";
194
215
User = "root";
216
+
StateDirectory = "download-space-guard";
217
+
LoadCredential = [
218
+
"matrix-token:${config.clan.core.vars.generators.archiver-matrix.files."matrix-access-token".path}"
219
+
];
195
220
};
196
221
};
197
222