# Startup & Logs

## Startup

All modules can be started manually but it is preferred to use `start_db_modules.py` script. On DroneBridge for Raspberry Pi the startup of modules is done by the `start_db` service. The source code sits inside the root directory of the repository. The service can be updated/registered using:

```bash
sudo cp /home/pi/DroneBridge/start_db /etc/init.d/start_db
sudo update-rc.d -f start_db remove
sudo update-rc.d start_db defaults
```

The status of the DroneBridge modules can be checked using:

```bash
sudo /etc/init.d/start_db [status|start|stop]
```

or:

```bash
service start_db [status|start|stop]
```

## Logs

### Local logs when connected via ssh

Since it is a service, all logs will be written to the journal. The logs can be viewed using one of the following commands:

```bash
journalctl -u start_db.service [-f for real-time]
```

```bash
systemctl | grep start_db | less
```

### Local logs when access via SD-card

All DroneBridge modules log to syslog. In `/DroneBridge/log/db_modules.log` are all relevant log entries.

### Remote real-time logging

Connect via TCP to the Raspberry Pi on port `1605` and you will receive realtime syslog logs. Forward the messages to your favourite log viewer like [Syslog Watcher](https://syslogwatcher.com/). Or use the provided Python 3 script below to output directly to console.

```python
import socket
from time import sleep

UDP_PORT_SYSLOG_SERVER = 1605
# Raspberry Pi IP when connected to GND station via WiFi: 192.168.2.1

if __name__ == '__main__':
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    reconnect = True
    while reconnect:
        try:
            sock.connect(('IP-OF-RPi', UDP_PORT_SYSLOG_SERVER))
            reconnect = False
        except ConnectionRefusedError:
            print("Retrying")
            sleep(1)

    while True:
        try:
            data = sock.recv(1024)
            print(data.decode("utf-8"))
        except KeyboardInterrupt:
            break
    socket.socket.close(sock)
```