CometBFT Ansible role

What is this?

This repository holds an Ansible role designed to manage the CometBFT configuration for a set of nodes in a testnet.

Although not mandatory, the testnet itself can be bootstrapped using Docker on the local workstation executing our accompanying Ansible playbook, ansible-role-cometbft-bootstrap.

The following instructions assume that you have used our bootstrap role to generate the initial configuration.

What's the testnet setup?

We assume 3 validator nodes and 3 sentry nodes.

Each validator can only receive traffic from the sentries.

The sentries can receive traffic from all sentries and validators.

How do I run the Ansible role?

Below are example playbooks. It assumes that your inventory contains:

• A hostgroup called cometbft_bootstrap that most likely has just localhost in it

• A hostgroup called cometbft_validators that has the 3 validator node IPs/hostnames in it

• A hostgroup called cometbft_sentries that has the 3 sentry node IPs/hostnames in it

• Optionally a cometbft group that includes all three (to share common inventory attributes)

The inventory attributes for each group:

cometbft group

# Version
cometbft_version: "0.38.19"

# Where the node home lives on each machine
cometbft_home: "/opt/cometbft"

# Where to build one-time testnet config on the control node (localhost, usually)
cometbft_testnet_dir: "/tmp/comet-testnet"

# Docker image
cometbft_docker_image: "cometbft/cometbft:{{ cometbft_version }}"

cometbft_validators group

cometbft_role: "validator"

cometbft_sentries group

cometbft_role: "sentry"

The inventory attributes for each validator node would contain something like this:

cometbft_node_index: 0 # incrementing for each other validator node
cometbft_partner: "my-sentry-1" # validator 2 would have sentry 2, etc

The inventory attributes for each sentry node would contain something like this:

cometbft_node_index: 3
cometbft_partner: "my-validator-1"

The playbook to bootstrap

---
- name: Bootstrap CometBFT testnet config
  hosts: cometbft_bootstrap
  connection: local
  gather_facts: false
  roles:
    - ansible-role-cometbft-bootstrap

- name: Push node config to each remote node
  hosts: "cometbft_validators:cometbft_sentries"
  become: true
  tasks:
    - name: Ensure cometbft home exists
      ansible.builtin.file:
        path: "{{ cometbft_home }}"
        state: directory
        mode: "0755"

    - name: Sync node{{ cometbft_node_index }} dir to remote CMTHOME
      ansible.posix.synchronize:
        src: "{{ cometbft_testnet_dir }}/node{{ cometbft_node_index }}/"
        dest: "{{ cometbft_home }}/"
        delete: yes

The playbook to configure (post-bootstrap, using this role)

---
- name: Set up CometBFT nodes
  hosts: "cometbft_validators:cometbft_sentries"
  become: true
  roles:
    - ansible-role-cometbft