Provisioning a Packer Image with chef-client

15 minutes
  • 3 Learning Objectives

About this Hands-on Lab

Packer lets us create machine images for a variety of platforms through code. Part of the image creation process involves provisioning the machine, which can be done with a variety of provisioners, including Chef. Packer is even able to connect to an existing Chef Infra Server and use the cookbooks there to provision the resulting image. In this lab, we’ll do just that to set up a web server image that hosts our company’s website.
**Note: You will find the AWS Access Key, Secret Access Key and the subnet ID required for the Packer configuration within the ‘Credentials’ tab (use the arrow button to see any hidden servers).**

Learning Objectives

Successfully complete this lab by achieving the following learning objectives:

Create the Client Key
  1. Move into the working directory for our Packer build.
  2. Generate a new client key called packer, and output the key to the working directory.
  3. There’s no need to change the provided configuration. Save and exit to finish.
Add the Provisioner
  1. Open the provided packer.json file.
  2. Since the chef-client provisioner installs Chef for us, there’s minimal pre-configuration we need to preform in the provided shell provisioner block. That said, we do need to ensure we can access our Chef Infra Server at chef.ec2.internal.
  3. We also need to move the packer.pem file we just created to the remote machine; to do this, we want to use the file provisioner. When working with chef-client, Packer uses the directory /tmp/packer-chef-client. For ease, we’ll store our key here. However, note that this directory has yet to be created. We’ll need to update our shell provisioner for this.
  4. Additionally, we want to make sure the certs supplied in ~/chef-repo/.chef/trusted_certs are added to the remote.
  5. We can now add our chef-client block. We’ll want to define our server URL, the validation client name and key path, as well as the location of our trusted certs and client key. Finally, we’ll want to supply the name of the node (packer) and the desired run list.
Test the Build
  1. Update the file with the provided access key, secret key, and subnet ID.
  2. Save and exit the file.
  3. Test the build.

Additional Resources

Alert: Please wait about 2 minutes before connecting via ssh to allow the lab to fully provision.

You have been tasked with building a Packer template for a new project. The resulting image build needs to provision an image that will host a website on an Ubuntu 20.04 server. Since your existing website is provisioned through Chef via a Chef Infra Server, you want to leverage that by having Packer provision using this existing setup and run the apache2::bookapp recipe against the remote machine.

A basic template that can provision an Ubuntu 20.04 server on AWS has been provided in the /home/cloud_user/packer/bookapp directory. Expand upon this to finish the template. Note that Chef workstation has already been configured on the provided workstation with /home/cloud_user/chef-repo working as the primary Chef working directory. The organization validator key for knife can be found at /home/cloud_user/chef-repo/.chef/bookapp.pem. A new client key will need to be created and moved to the remote host. The Chef workstation URL is https://chef.ec2.internal, and the expected organization is bookapp.

Additionally, trusted certs can be found at /home/cloud_user/.chef/trusted_certs.

Note: Packer removes the client key after a failed Packer build; if you perform a Packer run and it fails, the key will need to be created again.

What are Hands-on Labs

Hands-on Labs are real environments created by industry experts to help you learn. These environments help you gain knowledge and experience, practice without compromising your system, test without risk, destroy without fear, and let you learn from your mistakes. Hands-on Labs: practice your skills before delivering in the real world.

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