A Raspberry Pi maintenance utility
- Clone canary to
/root/canary/ cp /root/canary/canaryd.service /etc/systemd/system/ && chmod +x /etc/systemd/system/canaryd.service && systemctl enable --now canaryd
To send commands to an active canary server, communicate over TCP using the port specified in src/other/config.py. The simplest way to do this is via nc on a Linux machine.
echo '<command>' | nc <ip> <port>
Commands are designed to be immutable, meaning that clients should not be able to specify extrenuous infrmation to the server aside from the base commands. No arguments may be specified. No output can be received.
reboot: Reboot the server deviceupgrade: Run a full system upgrade viaapt-getping: Empty command; responds w/ positive acknowledgementgitpull: Pull pre-determined git repos on the device to update themselfupdate: Pull the latest changes for canary itself and restart the server
Make sure that your git client does not require authentication to pull new changes. Otherwise, the server will lock up waiting for a password authentication.
Canary can run a series of loops asynchronously. These can perform essential checks. For example, a process checker that reboots the device if it ever terminates, or a network checker that will reboot the device if it loses connection to the internet.
Canary bundles in a tiny init script helper. Scripts are executed every time canary starts up. Scripts MUST have execution permissions.
001-setup-watchdog.sh: Setup and install the Linux Kernel watchdog program to automatically reboot on system freezes002-setup-periodic-reboots.sh: Automatically reboot the pi at 3:00 AM via a crontab entry
While convenience and accessibility is essential, security cannot be sacrificed. Canary is designed to keep a one-way stream of information. That means that no output can ever be returned to the client. The client is not allowed to specify any external information to the server for interpreting. Commands are not allowed to have arguments. There is no room for ambiguity.
See src/other/config.py for documentation.
You can use the built-in canary client called birdhouse to communicate with clients in a cleaner manner. It creates a file called birdhouse (not to be confused with birdhouse.py). It will get created automatically upon first launch of birdhouse.
The birdhouse file stores a list of references to canary clients. It uses the format name:address:port. Entries can be managed manually or via the add and delete commands.
Commands can be sent to individual entries or all of them at once.