Many people have written blogs on how to create an EKS cluster with terraform, but I have added Ansible to it. The reasons for that were:

• I love Ansible :).
• It gives structure to the execution steps.
• You can add pre-steps and post-steps to the deployment.

About this blog

If you are new to Infrastructure as Code (IaC), this will be a step in the right direction.

This is an extension to terraform’s blog. You can find the architecture over there.

We are going to deploy 3 worker nodes in this demo. We will use Amazon EC2, Ansible, Terraform and Amazon EKS for this solution.

Pre-requisites:

1. Must have basic knowledge about AWS, Terraform, Shell Scripting, and Ansible.
2. Read the terraform’s blog. No need to execute anything from terraform’s blog.
3. AWS region must be Ohio (us-east-2).
4. Already created IAM role with admin permissions.

Let’s create an EKS cluster:

#!/bin/bash
yum update
yum install git -y
amazon-linux-extras install ansible2 -y
ansible-galaxy collection install community.general
git clone https://github.com/ashutoshvct/aws-eks-terraform-ansible.git
sleep 10s
cd aws-eks-terraform-ansible && nohup ansible-playbook install_eks.yaml -vv

sudo su
tail -f /var/log/cloud-init-output.log

Unraveling the mystery

• We create an EC2 Instance to execute our ansible playbook which contains the IaC.
• In this instance, we install git, ansible2, and Ansible modules and plugins which are needed by terraform.
• We clone the GitHub repo where the ansible-playbook is stored. Then, we execute the playbook in the background. Let’s go through the playbook:
  1. We are going to run the playbook on the instance we created. The playbook is stored at /aws-eks-terraform-ansible. If you want to make any edits in the playbook the filename is install_eks.yaml.
  2. The playbook will be run as a sudo user.
  3. We have a variable for terraform version which is set to 0.14.6.
  4. We update the yum repository.
  5. Install the dependencies like wget, AWS CLI v2, Terraform 0.14.6, AWS IAM Authenticator, and Kubectl.
  6. We then clone the repository to provision the EKS cluster.
  7. Then, we use the ansible community module to ensure that the terraform deploys the EKS cluster.
  8. In the end, we configure kubeconfig to the kubectl so that we can control the cluster via CLI.
     

Cleanup

1. SSH into the EC2 instance that we created to deploy the EKS cluster.
2. Execute the below commands:
   sudo su
cd /aws-eks-terraform-ansible
ansible-playbook destroy.yaml -vv
3. This will clean up all the terraform resources created. Once the process completes, terminate the EC2 Instance created for the EKS cluster setup.

Tips

These are just guidelines for you to improve the solution.

• Store the state file of terraform on S3.
• Improve the ansible-playbook to use native modules.
• Convert this solution to a one-liner.
• Change the yaml file according to your needs for example version of terraform, AWS CLI, or any other tool.
• Write another ansible-playbook to deploy any app into the new EKS worker nodes.

Do read my other blogs and stay tuned for more blogs! Don’t forget to share and connect with me on LinkedIn and Twitter.

The post Create an EKS cluster (AWS) using Terraform and Ansible appeared first on AWS Blog by Ashutosh.

Hello, my name is Ashutosh, you can connect with me on Linkedin or twitter.

I’m HashiCorp Certified Terraform Associate. I also hold CKA (Certified Kubernetes Administrator), AWS Solutions Architect Associate, Alibaba Cloud Associate and Google Automate IT with Python.

Why get Terraform Certified?

Terraform is an awesome IAC (Infrastructure as Code) tool, which enables us to deploy infrastructure on multi-cloud. If you work with multi-cloud or not it is good to have this tool skill set with you.

The cost of certification is very cheap which is $70.50 (excluding tax) as of today.

If you are new to terraform, this will be a good start it covers the basic concepts and also best practices of using terraform.

The preparation time for this certification is just 6 days or less.

Terraform is a tool for building, changing, and versioning infrastructure safely and efficiently.

Terraform is used to create, manage, and update infrastructure resources such as physical machines, VMs, network switches, containers, and more. Almost any infrastructure type can be represented as a resource in Terraform.

Prerequisites:

• Basic terminal knowledge
• Familiar with any Infrastructure/cloud provider.
• Basic scripting knowledge (Optional)

RoadMap:

1. Terraform hands-on course.
2. Documentations.
3. Practice.
4. Exam Simulator.

Step 1: The one with the master

The course referred by me for preparing the exam was on Udemy by Zeal Vora.

This course will take you 3 days to complete if you give it 4 hours daily. The content is very good and it also has practice questions at the end.

Step 2: The one where we read and read

Reading the Documentation is very Important, I strongly suggest you to go through the Exam review guide.

The document has sections which are going to be asked in the exam. They point you to the topic page, where you can read about them.

There are so many topics to read. You might get overwhelmed. Don’t try to skip the documentation part, it will help you clear your concepts.

HashiCorp has really put effort in building the documentation for the community which makes it easier for us to use terraform.

Step 3: The one where you just practice

So now you are almost prepared for the exam, but practice is very important.

Try to implement things that you already have in your cloud infrastructure. For example, you might have an EC2 instance running behind an ELB (Elastic Load Balancer) which is attached to ASG (Auto Scaling Group). Also create SG (Security Group) which has multiple rules.

Try to create a terraform template for this. I also suggest playing around updating and deleting resources. For example, after doing terraform apply, try updating the resource manually (change SG’s port, add or remove rules). Then perform terraform apply again to see what happens.

Another example would be to delete any resource manually and then with the help of this command terraform destroy -target resource-type.custom-name, check and see what happens.

Step 4: The one where you give the mock exam

Udemy has one more good course which helps you simulate exam like environment.

Some sample questions provided by HashiCorp.

Try to get 90% in both the mock test, after you are done with this you are ready to schedule your exam.

Don’t be nervous you will surely pass the exam. Best of Luck!

You can connect with me on Linkedin or twitter.

The post Passing HashiCorp Certified Terraform Associate appeared first on AWS Blog by Ashutosh.

CKA is not at all a hard exam. You will have enough time to solve it.

About this CKA blog:

So are you very new to Kubernetes? Have you failed your CKA exam in the first attempt and thinking about what you did wrong?

Well, you are in the right place. This is your blog to the glory. We will not only pass but clear our concepts too. Hello, my name is Ashutosh, you can connect with me on Linkedin or twitter.

PS: This is an approximately a two-week preparation course. However, the course is lengthy.

Prerequisites:

• You should have basic knowledge of Docker.
• You should know how to use the grep/awk utility.
• Basic Linux commands on Ubuntu 16.
• A dedicated time of 4-5 hours daily and a full day on holidays for two weeks.
• You should be aware of the Json/Yaml syntax.
• Fluent with any text editor.
• Fast typing. If you want to complete the exam in 2 hours.

Roadmap:

1. Basic of Kubernetes (Optional).
2. Kubernetes hands-on course.
3. CKA practice exercise.
4. More practice and Exam simulator.
5. Tips

Step 1: The one where it all Began

If you are already aware of the very basics of Kubernetes, you can skip this step and move on. But ask yourself this if you know the exact functioning difference between scheduler and control-manager. Also, if you know the exact function of Kubelet.

If you are unsure about those questions above, start with the basic course on Udemy. This course will get you started and I recommend it for absolute beginners.

Step 2: The one with the master

Well, this is a long course so prepare yourself, give it enough time. Be mentally prepared. This course will give you hands-on practice enough to pass the exam, but not to excel it.

So, try to use commands only to create any objects in k8s. Once you have completed the course, ask yourself this:

• Can you do any exercise?
• Have you done the mock exam at least 2 times, each in 15-25 mins?
• Do you know the k8s document very very well?
• Do you know how to extract data using Jsonpath, custom-columns or a sort-by option? Can you mix these commands and get the expected output? Note: This course does not have enough questions around Jsonpath.

Step 3: The one where you practice

Now, you have come a long way. You are just two steps in getting a full score.

Brace yourself because this is a practice test course, which will help you solve more questions. Remember you have to do only questions watching videos is not required. It will be just like repeating the course.

Please do all the exercises at the end of every section. Also, the Final Exam Preparation is also very good.

Ask yourself if you are done with course:

• Can you solve all the questions within 1-3 mins?
• Are you very comfortable with using the kubectl utility?

Step 4: The one where you just practice more

This is a Git repository with more questions, some of the questions are unnecessary. I have forked the repository so that I can improve it after some time.

If you are done with the above repository, try this CKA exam simulator made from docker-compose, although the timer doesn’t work. Just concentrate on the questions, not the functionality.

Note: Some questions related to audit are not part of the exam, you can skip them.

Now you are all set for the exam. But here are some tips that I will list down for you:

• Create a manifest for a pod with a command: kubectl run --generator=run-pod/v1 busybox --image=busybox --dry-run -o yaml --command "sleep 3000"
• Use -h option wherever possible. Example: create a container with an environment variable or use a service account with a pod.
• Go through the cheat sheet, just read it once or twice maybe. There are very useful commands related to Jsonpath.
• After completing a question, use the grep utility to find if the right pod has been created. For example: create a pod with Nginx image and name Nginx. So after you create it use this command: kubectl describe pods nginx | grep -ie image -ei name. Believe me, this command will save you a ton of time.
• While creating a cluster with kubeadm, If you are unable to get the worker node ready. Then, you can create the token and cert hash manually.
• Troubleshooting a cluster has more weight, so practice it quite enough. For example, the cluster is down and you can’t reach the API server. Do journalctl -u kubelet and then check for the issue so in some cases the staticPodPath is not present or incorrectly set.
• The text editor that you use, see some shortcuts online and practice it.
• Know your documentation very well. For example, taking backup of the etcd cluster should take you a maximum of 1-2 mins. Here is the document, I will open in the exam if I got a question-related to this.
• It is better to give an exam where you don’t have less bandwidth or electricity issue (office maybe).
• Switch the context at the start of every question no matter what.
• Clear the cache/cookies of your browser.
• There is no need to create an alias. Don’t waste your time.
• Don’t be nervous if you have followed all the steps properly you will get 90+ score, even 100.
• I will keep updating the blog with more tips.

If you liked this blog give it a shout-out on linkedin or twitter. Comment and let me know if you have any doubts.

The post Clearing CKA exam with 100% result appeared first on AWS Blog by Ashutosh.

Today, we will learn how to create custom CloudWatch metrics like RAM Usage and Disk Usage in centos 7?

What made me do this and why it is important?

Let’s see monitoring is a very important part of maintaining our servers. Also, AWS didn’t support these monitoring scripts for Centos. This made it difficult for a system administrator to monitor the environment.

Monitor RAM and Disk Usage in CentOS 7

A little bit about a script:

Script Name: mon-put-instance-data.pl

Purpose: This script is written in pearl and is used to collect metrics of swap, disk, and memory. In this blog, we will create custom CloudWatch metrics for RAM and disk.

Well, you are at the right place, because I’m going to show you how it’s done.

Prerequisite:

• Centos 7
• AWS IAM role with EC2 and CloudWatch access. You need to attach the role to your centos instance.

Creating custom CloudWatch Metrics (Centos 7)

1. 1. Install the following packages:

      sudo yum install perl-Switch perl-DateTime perl-Sys-Syslogperl-LWP-Protocol-https perl-Digest-SHA perl-LWP-Protocol-https -y

   2. We also need zip and unzip tools:

      sudo yum install zip unzip -y

   3. Download the monitoring scripts:

      curl http://aws-cloudwatch.s3.amazonaws.com/downloads/CloudWatchMonitoringScripts-1.2.1.zip -O

   4. Run the below commands to install the script:

      unzip CloudWatchMonitoringScripts-1.2.1.zip
      rm CloudWatchMonitoringScripts-1.2.1.zip
      cd aws-scripts-mon

   5. To verify the scripts are working enter this command:

      ./mon-put-instance-data.pl --mem-util --verify --verbose

   6. Now, let make this command automated by running it in crontab:

      crontab -e

   7. Enter these cronjob commands to send RAM and Disk Usage to AWS CloudWatch:
      Note: Instead of “/home/centos” enter your directory where you have installed the script. In the disk-path enter the mounted path of the volume whose metrics you want. In this case, I want metrics of the root EBS volume.

      */5 * * * * /home/centos/aws-scripts-mon/mon-put-instance-data.pl --mem-used --mem-util --mem-avail
      */5 * * * * /home/centos/aws-scripts-mon/mon-put-instance-data.pl --disk-path=/ --disk-space-util --disk-space-avail --disk-space-used
      

   8. Go to CloudWatch console and Create a new dashboard.
   9. Click on Add widget option and then select Linux system Metrics.
      

      Here you have it the screenshot of custom CloudWatch metrics:

      

      Feel free to comment and contact me for more blogs.

      Reference: AWS Monitoring, Blog by AWS

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