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Exercise 3

Join and leave the Axelar Network as a validator node.

Convert an existing Axelar Network node into a validator by attaching Bitcoin and Ethereum nodes and staking tokens. A validator participates in block creation, transaction signing, and voting.

Level#

Advanced

Disclaimer#

warning

Axelar Network is a work in progress. At no point in time should you transfer any real assets using Axelar. Only use testnet tokens that you're not afraid to lose. Axelar is not responsible for any assets lost, frozen, or unrecoverable in any state or condition. If you find a problem, please submit an issue to this repository following the template.

Prerequisites#

  • Complete all steps from Setup

Useful links#

Joining the Axelar testnet#

Follow the instructions in README.md to make sure your node is up to date and you received some test coins to your validator account.

Set up Bitcoin and Ethereum nodes#

As an Axelar Network validator, your Axelar node will vote on the status of Bitcoin and Ethereum transactions. To do so, you must first set up and configure your Bitcoin and Ethereum testnet nodes, and then provide the RPC endpoints to Axelar.

If you do not already have a Bitcoin testnet node and Ethereum Ropsten testnet node running, you can follow the instructions to set up and configure them, then skip to the next section Connect Bitcoin and Ethereum nodes to Axelar. You can also set up an alternative configuration of your choice.

Bitcoin and Ethereum node configuration will vary for different systems. Detailed configuration instructions for a local machine running macOS Bitcoin Core and Geth can be found here and used as a reference.

Bitcoin testnet node configuration#

  1. Ensure your Bitcoin testnet node is up to date. Stop the node before making any configuration changes.

  2. Enable the following configurations.

  • Enable the RPC Server.
  • Generate the RPC Auth value by supplying a username and password (make sure to save the username and password somewhere, you will need it later). An example RPC Auth value is 
rpcauth=jacky:a8e51174a095fe52491f4f487d41053a$9336f388b175ef3a8a63b248446aa3ccd0c8644bbb85ab005d447e164b7e9712
  • Set RPC Allow IP Address as 0.0.0.0/0.
  1. Find the RPC endpoint of your Bitcoin node for Axelar to connect to.

Your Bitcoin testnet node's RPC endpoint should be

http://{USERNAME}:{PASSWORD}@{IPADDRESS}:{PORT}

If your node is running on localhost, use host.docker.internal as the IPADDRESS since Axelar runs in a docker container. eg)

http://jacky:mypassword@host.docker.internal:18332

The username and password fields are the values you provided to the RPC Auth setting earlier. Write down the Bitcoin RPC endpoint as you will need it later.

  1. OPTIONAL: Test your Bitcoin node.

To test your setup, you can send an RPC request to your Bitcoin node using cURL. Use the following and replace the RPC endpoint.

curl -X POST http://jacky:mypassword@localhost:8332 \-H "Content-Type: application/json" \--data '{"jsonrpc":"2.0","method":"getblockchaininfo","params":[],"id":1}'

Ethereum Ropsten testnet node configuration#

  1. Ensure your Ropsten testnet node is up to date. Stop the node before making any configuration changes.

  2. Enable the following configurations.

  • Enable the HTTP-RPC Server for RPC communication.
  • Set HTTP-RPC virtual address as *
  • Set HTTP-RPC listening address as 0.0.0.0.
  1. Find the RPC endpoint of your Bitcoin node for Axelar to connect to.

Your Ethereum Ropsten testnet node's RPC endpoint should be

http://{IPADDRESS}:{PORT}

If your node is running on localhost, use host.docker.internal as the IPADDRESS since Axelar runs in a docker container. eg)

http://host.docker.internal:8332
  1. OPTIONAL: Test your Ethereum node.

To test your setup, you can send an RPC request to your Ethereum node using cURL. Use the following and replace the RPC endpoint.

curl -X POST http://localhost:8545 \-H "Content-Type: application/json" \--data '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'

Connect Bitcoin and Ethereum nodes to Axelar#

  1. Have an Axelar node fully caught up and running by completing the steps in README.md. Ensure you have some testnet coins on your validator address.

  2. Stop the Axelar node. Open a new terminal and run

docker stop $(docker ps -a -q)
docker rm $(docker ps -a -q)

  1. Go to your home directory and open ~/.axelar_testnet/shared/config.toml.

  2. Scroll to the bottom of the file, and look for ##### bitcoin bridge options ##### and ##### EVM bridges options #####.

  3. Find the rpc_addr line and replace the default RPC URL with the URL of your node, for both Bitcoin and Ethereum. Save the file. This RPC URL was found and written down during the Bitcoin and Ethereum node setup section.

  4. Start your Axelar node for the changes to take effect. Run the join/joinTestnet.sh script again, with the same --axelar-core, --tofnd (and optionally --root) parameters as before. Do NOT use the --reset-chain flag or your node will have to sync again from the beginning.

Joining the Network as a Validator#

  1. Enter Axelar node CLI
docker exec -it axelar-core sh
  1. Load funds onto your broadcaster account, which you will use later.

Find the address with

axelard keys show broadcaster -a

Go to Axelar faucet and get some coins on your broadcaster address.

Check that you received the funds

axelard q bank balances {broadcaster address}

eg)

axelard q bank balances axelar1p5nl00z6h5fuzyzfylhf8w7g3qj6lmlyryqmhg
  1. Find the minimum amount of coins you need to stake.

To become a full fledged validator that participates in threshold multi-party signatures, your validator needs to stake at least 0.5% or 1/200 of the total staking pool.

Go into the Axelar discord server and find the testnet channel. Open up the pinned messages at the top right corner and scroll down to the very first pinned message, which contains many links. Find the link for Monitoring as well as the testnet user login credentials and use it to sign in.

Once you are signed in to the monitoring dashboard, look for an entry called Bonded Tokens. This is the total pool of staked tokens in the network, denominated in axltest. However, later when you use the CLI, it actually accepts denominations in micro axltest where 1 axltest = 1,000,000 micro axltest.

So to find the minimum amount of coins you need to stake in the next step, calculate {total pool} * 1000000 / 200.

eg) If the dashboard displays 3k Bonded Tokens, the minimum amount is 3000 * 1000000 / 200 = 15000000.

⚠️ Important: Key shares for signing transactions on other chains are distributed proportionally to the validators' stakes on Axelar. In order to keep the number of key shares low for now, please delegate a similar amount of stake as existing validators have, i.e. 100000000axltest.

  1. Make your validator account a validator by staking some coins.

Use the following command, but change the amount to be larger than the minimum stake amount calculated in the last step. Remember that this is actually denominated in micro axltest. Also change the moniker to be a descriptive nickname for your validator.

axelard tx staking create-validator --yes \--amount "100000000axltest" \--moniker "testvalidator1" \--commission-rate="0.10" \--commission-max-rate="0.20" \--commission-max-change-rate="0.01" \--min-self-delegation="1" \--pubkey "$(axelard tendermint show-validator)" \--from validator \-b block

To check how many coins your validator has currently staked.

axelard q staking validator "$(axelard keys show validator --bech val -a)" | grep tokens

If you wish to stake more coins after the initial validator creation.

axelard tx staking delegate {axelarvaloper address} {amount} --from validator -y

eg)

axelard tx staking delegate "$(axelard keys show validator --bech val -a)" "100000000axltest" --from validator -y
  1. Register the broadcaster account as a proxy for your validator. Axelar network propagates messages from threshold multi-party computation protocols via the underlying consensus. The messages are signed and delivered via the blockchain.
axelard tx snapshot registerProxy broadcaster --from validator -y
  1. Check that your node's vald and tofnd are connected properly. As a validator, your axelar-core container will talk with your tofnd container through the vald module. This is important when events such as key rotation happens on the network.

First, check that the vald process is running. Run the following commands in a new terminal.

docker exec axelar-core ps

Look for a process called vald-start. If you see it, then your vald module has successfully started and connected with tofnd. You're good to go!

Start-up troubleshoot#

If the process was missing, check if tofnd is running. Install the nmap command if you do not have it, and check the tofnd port

nmap -p 50051 localhost

Look for the STATE of the port, which should be open or closed. If the port is closed, restart your node and ensure tofnd is running. If the port is open, then there is a connection issue between vald and tofnd.

To fix the connectivity issue, find the tofnd container address manually and provide it to vald. Find the tofnd address.

docker inspect tofnd

Near the bottom of the JSON output, look for Networks, then bridge, IPAddress, and copy the address listed. Next, ping the IP Address from inside Axelar Core to see if it works. Install the ping command if it does not exist already.

docker exec axelar-core ping {your tofnd IP Address}

eg)

docker exec axelar-core ping 172.17.0.2

You should see entries starting to appear one by one if the connection succeeded. Stop the ping with Control + C. Save this IP address.

Next, query your validator address with

docker exec axelar-core axelard keys show validator --bech val -a
caution

Make sure the validator address that is returned starts with axelarvaloper

Now, start vald, providing the IP address and validator address:

docker exec axelar-core axelard vald-start --tofnd-host {your tofnd IP Address} --validator-addr {your validator address}

eg)

docker exec axelar-core axelard vald-start --tofnd-host 172.17.0.2 --validator-addr axelarvaloper1y4vplrpdaqplje8q4p4j32t3cqqmea9830umwl

Your vald should be connected properly. Confirm this by running the following and looking for an vald-start entry.

docker exec axelar-core ps

Your node is now a validator! Stay as a validator and keep your node running for at least a day. If you wish to stop being a validator, follow the instructions in the next section.

Leaving the Network as a Validator#

  1. Deactivate your broadcaster account.
axelard tx snapshot deactivateProxy --from validator -y -b block

  1. Wait until the next key rotation for the changes to take place. In this release, we're triggering key rotation about once a day. So come back in 24 hours, and continue to the next step. If you still get an error after 24 hours, reach out to a team member.

  2. Release your staked coins.

axelard tx staking unbond {axelarvaloper address} {amount} --from validator -y -b block

eg)

axelard tx staking unbond "$(axelard keys show validator --bech val -a)" "100000000axltest" --from validator -y -b block

amount refers to how many coins you wish to remove from the stake. You can change the amount.

To preserve network stability, the staked coins are held for roughly 1 day starting from the unbond request before being unlocked and returned to the validator account.