This script has three main tasks:
- Watch for Missed Blocks
- Switch to Backup-Node(s) and / or disable the witness
- Alert the Witness via SMS of missed blocks
I want to mention that the script has not yet been tested in the case of a real missed-block. Theoretically, everything should work. But - I've also implented a testmode - which only notifies you via console.log and doesn't interact with the blockchain or SMS, just as a way to test the reaction.
I hope to get some insights about what works and what doesn't with this release - but: I don't take any responsibility if the script doesn't behave as expected.
The Witness-Failover script was written in pure ES6 JS and thus needs babel to compile. In addition it uses dsteem as RPC-Client library.
Make sure you have installed npm & node.
1.) Clone the repository & go into the folder
git clone https://github.com/therealwolf42/witness-failover.git
cd witness-failover
2.) Install dependencies
npm i
3.) Copy config.example.json and edit config.json
cp config.example.json config.json
The INTERVAL - how often it should check for missed blocks - is in minutes. And this depends on how often you produce a block. I'm in the top 50 and produce one block roughly every hour. That's why I used 20 minutes. But for a TOP 20 Witness, this number has to be a lot lower.
{
"TEST_MODE": "DISABLED",
"RPC_NODES": [
"https://api.steemit.com",
"https://steemd.privex.io",
"https://gtg.steem.house:8090",
"https://rpc.buildteam.io",
"https://steemd.minnowsupportproject.org"
],
"WITNESS": "",
"BACKUP_KEYS": [
""
],
"MISSED_BLOCKS_THRESHOLD":2,
"INTERVAL":20,
"USE_SMS_ALERT":"ENABLED",
"SEND_AFTER_EVERY_MISSED":"ENABLED"
}
4.) Create an .env file (touch .env) with the following variables and paste in your own (!)
ACTIVE_KEY=
NEXMO_API_KEY=
NEXMO_API_SECRET=
PHONE_NUMBER=
Make sure that you include your country-code in your phone_number - e.g. 49123456789 (+49 would be Germany)
After all this - you should have the 2 marked files in your folder:
NEXMO is a provider similar to TWILIO & co. but I personally find it a bit cheaper to use. In the future I will modify the script to use another alternative - but for now this should be enough.
You can create an account here: https://www.nexmo.com/
There are currently 3 available script-commands.
1.) Start Witness-Failover
This command will start the script for you.
npm start
2.) Testing SMS
To make sure that you entered a valid phone-number, you can test it by running the command below: (this SMS will cost you a few cents)
npm run test_sms
3.) Building /dist folder from source
This happens automatically if you use npm start - however you might want to run node dist/index.js yourself - in that case you can build it yourself.
npm run build
I personally use either tmux or pm2 to run scripts in the background - but in this case I'll stick with pm2.
npm install pm2 -g
pm2 start npm --name "failover" -- start
pm2 logs failover
Contact me on steemit.chat @therealwolf or on discord therealwolf#5970