cka_2nd_edition_live_lessons_by_pearson

Packer and Terraform to spin up a CKA cluster, spec'd out as required by the CKA 2nd Edition Video course published by Pearson IT Certification.

General information

Each AWS resource is a Terraform root module, which is created by calling modules from various terraform-aws-modules repositories.

The packer directory has a brief README as well. You can read this README top down to get this lab built fairly quickly.

You will be instructed to start in the packer directory to get the AMI built, further below.

Local requirements

• Install Packer, I used version 1.7.8
• Install AWS CLI, and you have your AWS access keys configured locally in ~/.aws. You may likely have this done already, for your AWS personal account.
• Install Terraform. I used 0.14.0. Use tfenv to install 0.14.0 if you'd like.
• We'll need an ssh key-pair, please name it cka_lab_rsa as that is what this code references. We'll need that key created and/or placed its usual spot, ~/.ssh.

user ~ $ ssh-keygen
..
..

user ~ $ ll .ssh | grep cka
-rw-------   1 user  staff   2.5K Nov  8 15:48 cka_lab_rsa
-rw-r--r--   1 user  staff   578B Nov  8 15:48 cka_lab_rsa.pub
user ~ $

INPUTS

Due to the nature of the lab, there are only a few inputs you need to provide.

I've included a cka_lab.tfvars file, which requires 3 variables to be declared (you can pick another region, or leave that as is):

region = "us-east-1a"

public_key = ""

my_current_ip = ""

All the other variables in variables.tf should remain the same, as they are spec'd per the lab instructor.. for lab parity.

OUTPUTS

After terraform is ran, we'll get the public IP of the kube_controller, so we can ssh to the controller:

Outputs:

kube_controller_public_ip = "55.55.55.55"

Building the Lab

1. First head over to the packer directory. You'll see another README that will show you how to get the AMI built. Once you're done with that, proceed to step 2 below.

2. Now we can spin up the lab. You'll get an IP address you can ssh to, using the private key from the keypair you created previously.
   a. You must cd .. and go back into the root of the repo to run Terraform, as you were previously working in the the packer directory for step 1.

terraform apply --var-file=cka_lab.tfvars --auto-approve
...
...
...
module.cka_lab_vpc.aws_route.private_nat_gateway[0]: Creating...
module.cka_lab_vpc.aws_route.private_nat_gateway[0]: Creation complete after 1s [id=r-rtb-05d3fe23d26942ba71080289494]

Apply complete! Resources: 18 added, 0 changed, 0 destroyed.

Outputs:

kube_controller_public_ip = "55.55.55.55"

SSH to the controller using the centos user, and the ssh key we created earlier:

$ ssh -i ~/.ssh/cka_lab [email protected]

SSH key based authentication is configured on all instances, /etc/hosts and ~/.ssh/config will be all setup too. That being said, you can ssh to any instance via the hostname, such as: ssh worker-1, ssh-worker-2, ssh-worker-3, ssh controller

When you're done, destroy all the resources to keep your AWS bill nice and low.

terraform destroy --var-file=cka_lab.tfvars --auto-approve

How long will it take to spin up the lab?

For Packer, roughly 7 minutes to create the AMI:

Build 'cka lab ami.amazon-ebs.k8s-lab-ami' finished after 6 minutes 53 seconds.

==> Wait completed after 6 minutes 53 seconds

For Terraform, roughly 1.5 minutes to spin up the lab using the AMI we just created:

21:10 $ date
Wed Feb 16 21:10:20 CST 2022
✔ ~/github/cka_2nd_edition_live_lessons_by_pearson [main|✚ 3⚑ 4] 
21:10 $ terraform apply --var-file=cka_lab.tfvars --auto-approve
..
..
..
✔ ~/github/cka_2nd_edition_live_lessons_by_pearson [main|✚ 3⚑ 4] 
21:11 $ date
Wed Feb 16 21:11:57 CST 2022

Total time: ~8.5 minutes

When you're completely done with the lab and no longer need to use it anymore

• The only artifacts left that you'll want to delete should be the ami we created.
• You can unsubscribe from the CentOS 7 AMI when you're done with the lab as well, and remove that AMI from your account too.

That should be it, as everything managed by Terraform will be destroyed when you destroy it.