Why I Looked Into Chef

Managing servers one by one doesn’t scale. I set up Chef to store server configs as code — a Chef server, a workstation where I write recipes, and a node that pulls its config automatically.

Note: I did this on Ubuntu 18.04 using .deb packages and apt.

Chef Server

The Chef server acts as the central hub for all workstations and nodes under Chef management. Configuration changes made on workstations are pushed to the Chef server, where they are pulled by nodes using chef-client to apply the configurations.

Install the Chef Server

  1. Download the latest Chef server core:

    wget https://packages.chef.io/files/stable/chef-server/13.1.13/ubuntu/18.04/chef-server-core_13.1.13-1_amd64.deb

  2. Install the server:

    sudo dpkg -i chef-server-core_*.deb

  3. Start the Chef server services:

    sudo chef-server-ctl reconfigure

Create a Chef User and Organization

To link workstations and nodes to the Chef server, create an administrator and organization with associated RSA private keys.

  1. Create a .chef directory to store the keys:

    mkdir ~/.chef

  2. Create a user with chef-server-ctl, replacing placeholders with your details:

    sudo chef-server-ctl user-create USER_NAME FIRST_NAME LAST_NAME EMAIL 'PASSWORD' --filename ~/.chef/USER_NAME.pem

  3. List all users:

    sudo chef-server-ctl user-list

  4. Create an organization and associate the user:

    sudo chef-server-ctl org-create ORG_NAME "ORG_FULL_NAME" --association_user USER_NAME --filename ~/.chef/ORG_NAME.pem

  5. List all organizations:

    sudo chef-server-ctl org-list

With the Chef server installed and RSA keys generated, the workstation can now be configured.

Chef Workstations

The Chef workstation is where recipes, cookbooks, attributes, and configurations are managed. It can be a local machine or a remote server.

Setting Up a Workstation

  1. Download the latest Chef Workstation:

    wget https://packages.chef.io/files/stable/chef-workstation/0.2.43/ubuntu/18.04/chef-workstation_0.2.43-1_amd64.deb

  2. Install Chef Workstation:

    sudo dpkg -i chef-workstation_*.deb

  3. Create your Chef repository:

    chef generate repo chef-repo

  4. Ensure that your workstation’s /etc/hosts file correctly maps IP addresses to the Chef server and workstation hostnames.

  5. Create a .chef subdirectory within chef-repo to store authentication files:

    mkdir ~/chef-repo/.chef
cd chef-repo

Add the RSA Private Keys

Authentication between the Chef server and workstations/nodes is performed using public-key encryption. Copy the RSA private keys from the Chef server to the workstation.

  1. Generate an RSA key pair on the workstation (if not already available):

    ssh-keygen -b 4096

  2. Upload the workstation’s public key to the Chef server:

    ssh-copy-id example_user@192.0.2.0

  3. Copy the .pem files from the Chef server to the workstation:

    scp example_user@192.0.2.0:~/.chef/*.pem ~/chef-repo/.chef/

  4. Confirm the files were copied:

    ls ~/chef-repo/.chef

Bootstrap a Node

Bootstrapping a node installs the Chef client and validates the node, allowing it to pull and apply configurations from the Chef server.

  1. Update the /etc/hosts file on the node to correctly identify the node, Chef server, and workstation.

  2. From the workstation, navigate to the .chef directory:

    cd ~/chef-repo/.chef

  3. Bootstrap the node:

    knife bootstrap 192.0.2.0 -x root -P password --node-name nodename

  4. Verify the node has been bootstrapped:

    knife client list

  5. Add the bootstrapped node to the workstation’s /etc/hosts file.

For more detailed information, refer to the Linode guide.