Chef | Notion

Setting up and using Chef, a powerful configuration management tool, involves creating cookbooks, recipes, and possibly roles and environments to manage your infrastructure. Here’s a step-by-step guide to setting up Chef along with some example configurations.

Setting Up Chef

Prerequisites

Chef Workstation: This includes all the tools you need to author cookbooks, test them, and manage multiple Chef Infra Servers.
Chef Server: The central repository where cookbooks are stored and policy details are managed. It manages multiple nodes.
Nodes: The servers (virtual or physical) managed by Chef.

Step 1: Install Chef Workstation

Download and Install:
- Go to the Chef Workstation download page and download the appropriate package for your operating system.
- Install the package using standard installation methods for your OS.
Verify Installation:
- Open a terminal and run chef --version to ensure it is installed correctly.

Step 2: Set Up Chef Server

Install Chef Server:
- You can use managed Chef Infra Server (Hosted Chef) or install your own. To install, download the package from Chef’s download page and follow the installation instructions.

Configure Chef Server:

Run the following commands to start services and create an admin user:

sudo chef-server-ctl reconfigure
sudo chef-server-ctl user-create USER_NAME FIRST_NAME LAST_NAME EMAIL 'PASSWORD' --filename USERNAME.pem
sudo chef-server-ctl org-create SHORT_NAME "FULL_ORGANIZATION_NAME" --association_user USER_NAME --filename ORGANIZATION-validator.pem

Download Starter Kit (if using Hosted Chef or Chef Automate):
- Log into the Chef management console.
- Go to the administration tab and download the starter kit which will include configuration files and keys to connect workstations to the Chef server.

Step 3: Create a Cookbook

Create Cookbook:
- Use Chef Workstation to create a cookbook. In your terminal, run:
```
chef generate cookbook cookbooks/my_cookbook
```

Add Recipes:

Edit cookbooks/my_cookbook/recipes/default.rb to define what state your system should be in. For example, to ensure that Apache is installed and running, you could write:

package 'httpd' do
  action :install
end

service 'httpd' do
  action [:start, :enable]
end

file '/var/www/html/index.html' do
  content '<html>This is a placeholder</html>'
  action :create
end

Step 4: Upload Cookbook to Chef Server

Upload Cookbook:
- Run the following command from your Chef Workstation:
```
knife cookbook upload my_cookbook
```

Step 5: Add a Node

Bootstrap a Node:
- Use knife to bootstrap a new node (this installs the Chef client on the node and registers it with the Chef server). You need the node's SSH credentials or administrator password.
```
knife bootstrap ADDRESS --ssh-user USER --ssh-password 'PASSWORD' --sudo --use-sudo-password --node-name NODE_NAME --run-list 'recipe[my_cookbook]'
```