Step-by-Step Guide: Setting Up a Polkadot Validator Node for Network Security and Staking Rewards with ansbile and systemd

Setting up a Substrate Polkadot validator node using Ansible and systemd is an efficient way to automate the deployment and management of your validator node. Ansible allows you to define the desired state of your infrastructure and execute tasks across multiple servers. In this tutorial, we'll guide you through the process of installing a Polkadot validator node using Ansible and systemd.

Prerequisites:

Before you begin, ensure you have the following prerequisites:

1. A local machine or control node with Ansible installed.
2. Remote servers or VPS instances where you want to deploy the validator node.
3. SSH access to the remote servers with passwordless sudo privileges.
4. A basic understanding of Ansible.

Step 1: Set Up Ansible on Your Local Machine

1. Install Ansible on your local machine if you haven't already
2. Create an Ansible inventory file (hosts.ini) that lists the IP addresses or hostnames of your remote servers

[validators]
validator1 ansible_host=validator1_ip_address
validator2 ansible_host=validator2_ip_address
# Add more servers as needed

Step 2: Create an Ansible Playbook

An Ansible playbook is a YAML file that defines the tasks you want to automate. Create a playbook file (e.g., deploy_validator.yml) with the following content:

---
- hosts: validators
  become: yes
  tasks:
    - name: Update system packages
      apt:
        update_cache: yes
      tags:
        - common

    - name: Install required packages
      apt:
        name: "{{ item }}"
        state: present
      loop:
        - git
        - curl
        - build-essential
        - cmake
        - clang
        - libssl-dev
      tags:
        - common

    - name: Install Rust
      shell: >
        curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
      args:
        executable: /bin/bash
      environment:
        RUSTUP_HOME: /opt/rustup
        CARGO_HOME: /opt/cargo
      tags:
        - rust

    - name: Add Rust to PATH
      lineinfile:
        path: "{{ item }}"
        line: 'export PATH=$PATH:/opt/cargo/bin:/opt/rustup/bin'
        insertafter: EOF
      loop:
        - /etc/profile
        - /home/{{ ansible_user }}/.bashrc
      tags:
        - rust

    - name: Clone Polkadot repository
      git:
        repo: https://github.com/paritytech/polkadot.git
        dest: /opt/polkadot
        version: master
        force: yes
      tags:
        - polkadot

    - name: Build the Validator Node
      command: >
        /opt/cargo/bin/cargo build --release --features=validator
      args:
        chdir: /opt/polkadot
      tags:
        - polkadot

    - name: Create Validator Configuration
      template:
        src: validator-config.json.j2
        dest: /opt/polkadot/validator-config.json
      tags:
        - polkadot

    - name: Create systemd service unit file
      template:
        src: polkadot-validator.service.j2
        dest: /etc/systemd/system/polkadot-validator.service
      notify: Reload systemd
      tags:
        - systemd

    - name: Start and enable Polkadot validator service
      systemd:
        name: polkadot-validator
        state: started
        enabled: yes
      tags:
        - systemd

Step 3: Create Template Files

Create two template files, one for the Polkadot validator configuration (validator-config.json.j2) and one for the systemd service unit (polkadot-validator.service.j2). Here's an example template for validator-config.json.j2:

{
  "chain": "polkadot",
  "validator": true,
  "key": "your_validator_key",
  "validator-name": "YourValidatorName",
  "validator-payment-dest": "your_payment_address",
  "validator-stash": "your_stash_address",
  "rpc-cors": "all",
  "rpc-external": true,
  "rpc-port": 9933,
  "ws-external": true,
  "ws-port": 9944,
  "ws-allow-origin": "all",
  "rpc-methods": "Unsafe",
  "rpc-threads": 4,
  "rpc-server": true,
  "name": "YourValidatorName",
  "execution": "Native",
  "db": "RocksDb"
}

And here's an example template for polkadot-validator.service.j2:

[Unit]
Description=Polkadot Validator Node

[Service]
ExecStart=/opt/polkadot/target/release/polkadot \
  --chain polkadot \
  --validator \
  --key your_validator_key \
  --validator-name "YourValidatorName" \
  --validator-payment-dest your_payment_address \
  --validator-stash your_stash_address \
  --rpc-cors all \
  --rpc-external \
  --rpc-port 9933 \
  --ws-external \
  --ws-port 9944 \
  --ws-allow-origin all \
  --rpc-methods Unsafe \
  --rpc-threads 4 \
  --rpc-server \
  --name YourValidatorName \
  --execution Native \
  --db RocksDb
Restart=always
User={{ ansible_user }}
Group={{ ansible_user }}

[Install]
WantedBy=multi-user.target

Step 4: Run the Ansible Playbook

Run the Ansible playbook on your local machine to deploy the Polkadot validator nodes on your remote servers:

ansible-playbook -i hosts.ini deploy_validator.yml

Ansible will execute the defined tasks on each server listed in the inventory file, automating the installation and configuration process.

Step 5: Monitor Your Validator Node (Optional)

You can use monitoring tools like Prometheus and Grafana to keep track of your validator's performance and status.

Step 6: Bond Tokens (Optional)

To become an active validator, you need to bond a certain amount of DOT tokens. This is done through the Polkadot governance interface or by transferring tokens to your validator's account.

Step 7: Register Your Validator (Optional)

To officially become a validator on the Polkadot network, you'll need to register your validator using the governance process.

Congratulations! You've successfully automated the deployment of a Substrate Polkadot validator node using Ansible and systems.

This setup ensures that your validator nodes run continuously and automatically recover from failures or server reboots.