How to Install Puppet Bolt to Automate Sysadmin Tasks

Puppet Bolt is an open-source IT automation tool that allows you to execute commands, scripts, and tasks across remote nodes without needing an agent installed. It provides a simple yet powerful way to automate manual sysadmin work and achieve consistency across your infrastructure. In this comprehensive guide, we will cover how to install Bolt and use it to run commands, scripts, tasks and more across remote Linux and Windows systems.

Introduction to Puppet Bolt

Puppet Bolt is developed by Puppet, the leading developer of open source infrastructure automation software. Some key highlights of Bolt:

Agentless – No need to install any agent/client software on remote nodes. Works over SSH/WinRM.
Efficient – Can run tasks on thousands of nodes in parallel. Saves huge time compared to manual work.
Powerful – Supports executing commands, scripts, tasks, file uploads/downloads on remote nodes.
Simple – Very easy to get started. YAML based inventory system to manage nodes.
Secure – Relies on SSH or WinRM for transport. Supports RBAC and secrets management.

Bolt allows you to reuse existing scripts and commands. It is cross-platform and can be installed on Linux, Windows and macOS systems. The major benefits of using Bolt include:

Time savings from automating repetitive tasks
Consistency and reliability in task execution
Easy sharing and reuse of tasks across nodes
No dependency on any agent software

Next, let us look at how to install Bolt on Linux systems.

Installing Bolt on Linux

The following installation steps work for Debian/Ubuntu flavors of Linux. For other distros like RHEL/CentOS, the setup is very similar – just use the relevant package manager instead of apt.

Bolt prerequisites:

Ruby 2.4 or higher
SSH connectivity between nodes for remote execution

First, add the Puppet repository:

wget https://apt.puppet.com/puppet6-release-bionic.deb
sudo dpkg -i puppet6-release-bionic.deb

Next, update the packages and install the bolt package:

sudo apt-get update
sudo apt-get install puppet-bolt

The bolt command can now be used to run Bolt tasks.

Configuring SSH Access

Bolt relies on SSH connectivity between the control machine and remote nodes for executing tasks. Passwordless SSH using key based authentication must be set up.

Generate an SSH key pair on the control node:

ssh-keygen -t rsa

Copy the public key to all remote nodes:

ssh-copy-id remote_username@remote_host

Confirm you can SSH into remote hosts without a password prompt. Bolt uses this SSH connection for remote execution.

Writing Bolt Commands

The bolt command is used to invoke Bolt functionality. Some examples of using Bolt:

Run commands

Run a command on remote Linux nodes:

bolt command run ‘uname -a‘ --nodes node1,node2

Run a PowerShell command on Windows nodes:

bolt command run ‘Get-Process‘ --nodes win1,win2

Run scripts

Run a local script on remote nodes:

bolt script run /local/script.sh --nodes node1,node2

Run tasks

Tasks encapsulate scripts/code into reusable units. Example installing a package using a built-in package task:

bolt task run package action=install name=nginx --nodes web1,web2

Upload files

Upload a file to multiple nodes:

bolt file upload /local/file.txt /remote/dir --nodes node1,node2

There are many more capabilities like running plans, executing queries, applying Puppet code and more.

Using Bolt Inventory

Bolt uses an inventory file (inventory.yaml by default) to store node information. This allows querying nodes by defined groups and setting config options.

Example inventory file:

---
groups:
  - name: web_servers 
    nodes:
      - node1
      - node2

  - name: db_servers
    nodes:
     - node3
     - node4   

config:
  ssh:
    host-key-check: false

The inventory can then be referenced in Bolt commands:

bolt task run package action=install name=nginx --inventoryfile inventory.yaml

Conclusion

Puppet Bolt provides a very powerful way to automate tasks across remote nodes. Some key takeaways:

Install Bolt on your preferred platform like Linux, Windows or MacOS
Setup SSH or WinRM for connectivity across nodes
Use Bolt to execute commands, scripts, tasks, upload files and more
Manage nodes in an inventory file for easy access
Reuse existing scripts and commands for time savings

Bolt allows infrastructure automation in a simple yet powerful manner without requiring any agents on remote nodes. To learn more, visit the Puppet Bolt docs at https://puppet.com/docs/bolt/latest/bolt.html.