RTL-SDR + readsb + tar1090 + watchdog

1) Préparer la clé RTL-SDR

Vérifier la détection et installer les outils de test.

lsusb | grep -i realtek
sudo apt-get update
sudo apt-get install -y rtl-sdr
sudo rtl_test -t

2) Désactiver le driver DVB du noyau (évite les conflits)

echo -e "blacklist dvb_usb_rtl28xxu\nblacklist rtl2832\nblacklist rtl2830" | sudo tee /etc/modprobe.d/blacklist-rtlsdr.conf
sudo update-initramfs -u
sudo modprobe -r dvb_usb_rtl28xxu rtl2832 rtl2830 2>/dev/null || true

3) Installer et configurer readsb

Éditer /etc/default/readsb :

RECEIVER_OPTIONS="--device 0 --device-type rtlsdr --gain auto"
DECODER_OPTIONS="--fix --aggressive"
NET_OPTIONS="--net --net-heartbeat 60 --net-ro-size 1250 --net-ro-interval 0.05 --net-ri-port 30001 --net-ro-port 30002 --net-sbs-port 30003 --net-bi-port 30004,30104 --net-bo-port 30005"
JSON_OPTIONS="--write-json /run/readsb --write-interval 1"

Puis démarrer et vérifier :

sudo systemctl daemon-reload
sudo systemctl enable --now readsb
systemctl status readsb --no-pager
ls -l /run/readsb/aircraft.json

4) Installer le serveur web lighttpd pour tar1090

sudo apt-get install -y lighttpd
sudo systemctl enable --now lighttpd

Créer /etc/lighttpd/conf-available/89-tar1090.conf :

alias.url += ( "/tar1090/" => "/usr/share/tar1090/html/" )
$HTTP["url"] =~ "^/tar1090/data/" {
  alias.url += ( "/tar1090/data/" => "/run/readsb/" )
}

Activer et tester :

sudo lighttpd-enable-mod tar1090
sudo systemctl reload lighttpd
curl -I http://localhost/tar1090/
curl -I http://localhost/tar1090/data/aircraft.json

5) Ajouter un watchdog (redémarrage auto si le flux se fige)

Script /usr/local/bin/readsb-watchdog.sh :

#!/usr/bin/env bash
JSON_FILE="/run/readsb/aircraft.json"
SERVICE="readsb.service"
THRESHOLD_MIN=3
STATE_FILE="/run/readsb-watchdog.state"

messages=$(jq -r '.messages // empty' "$JSON_FILE" 2>/dev/null || true)
[[ -z "$messages" ]] && exit 0

now=$(date +%s)
last_messages=0
last_change=$now
[[ -f "$STATE_FILE" ]] && read -r last_messages last_change < "$STATE_FILE"

if [[ "$messages" -gt "$last_messages" ]]; then
  echo "$messages $now" > "$STATE_FILE"
  exit 0
fi

elapsed=$(( now - last_change ))
limit=$(( THRESHOLD_MIN * 60 ))

if [[ "$elapsed" -ge "$limit" ]]; then
  logger -t readsb-watchdog "No new messages for ${elapsed}s, restarting $SERVICE"
  systemctl restart "$SERVICE"
  echo "$messages $now" > "$STATE_FILE"
fi

Rendre exécutable :

sudo chmod +x /usr/local/bin/readsb-watchdog.sh

Unit systemd /etc/systemd/system/readsb-watchdog.service

[Unit]
Description=Watchdog readsb - restart if stalled
After=readsb.service

[Service]
Type=oneshot
ExecStart=/usr/local/bin/readsb-watchdog.sh

Timer /etc/systemd/system/readsb-watchdog.timer

[Unit]
Description=Run readsb watchdog every minute

[Timer]
OnBootSec=1min
OnUnitActiveSec=1min
AccuracySec=10s
Unit=readsb-watchdog.service

[Install]
WantedBy=timers.target

Activer :

sudo systemctl daemon-reload
sudo systemctl enable --now readsb-watchdog.timer
systemctl list-timers | grep readsb-watchdog

6) Vérifications rapides

head -c 200 /run/readsb/aircraft.json
curl -I http://localhost/tar1090/
journalctl -t readsb-watchdog -n 20 --no-pager