Astar/Shiden Collator Block Check Script

This scripts interrogates an Astar/Shiden collator for the last block it has successfully built and restarts it if it is trailing behind the head of the chain too far.

Installation

Requirements

• Python3
• pip
• virtualenv

On Debian/Ubuntu based systems the following should be enough to get those:

sudo apt-get install -qy python3-pip python3-virtualenv

Install the script

git clone https://github.com/cardinate-io/collator-check-blocks.git
cd collator-check-blocks
sudo python3 -m virtualenv /usr/local/lib/collator-check-blocks
sudo /usr/local/lib/collator-check-blocks/bin/pip install -r requirements.txt
sudo cp collator-check-blocks.py /usr/local/lib/collator-check-blocks/bin/
echo "COLLATOR_ADDRESS=$YOUR_COLLATOR_WALLET_ADDRESS" | sudo tee /etc/default/collator-check-blocks
echo "*/5 * * * * root /usr/local/lib/collator-check-blocks/bin/python /usr/local/lib/collator-check-blocks/bin/collator-check-blocks.py >/dev/null 2>&1" | sudo tee /etc/cron.d/collator-check-blocks

This installs the script and its Python dependencies into a virtualenv and creates a cron job that runs every 5 minutes. Make sure to substitute $YOUR_COLLATOR_WALLET_ADDRESS with the on-chain account of the collator.

Configuration

The script can be configured through environment variables or through an env file at /etc/default/collator-check-blocks. The following settings are available. Usually, it should be sufficient to specify COLLATOR_ADDRESS (and potentially tweak COLLATOR_BLOCK_DELTA_FAIL_THRESHOLD)

variable	meaning	default
COLLATOR_ADDRESS	On chain address of the collator wallet
COLLATOR_WS_URL	WS URL where the collator can be reached	ws://127.0.0.1:9944
COLLATOR_JSONRPC_URL	JSON-RPC URL where the collator can be reached	ws://127.0.0.1:9933
COLLATOR_RESTART_OFFSET	Amount of seconds to wait between collator restarts	1,800
COLLATOR_RESTART_COMMAND	The command to run in a subshell in order to restart the collator. The calling process needs to have sufficient privileges	systemctl restart astar.service
COLLATOR_RESTART_SENTINEL	The script will write the last restart time to the file named here	/tmp/collator-check-blocks
COLLATOR_LOG_FILE	The file where the script will write logs to	/var/log/collator-check-blocks.log
COLLATOR_BLOCK_DELTA_FAIL_THRESHOLD	The number of blocks that the last block built by the collator is allowed to fall behind the head of the chain	150