SETTING UP A SINGLE-NODE KUBERNETES CLUSTER ON AWS

In Part 1 of our five-part series, we’ve already secured the SSH port and created a key pair. Now, let’s choose the right “ubuntu” Amazon Machine Image (AMI) and select an appropriate EC2 instance type. For our initial configuration, we recommend starting with a “t2.micro” instance.

Step 1: Launching an Ubuntu EC2 Instance

1. Access the EC2 Console:

• Navigate to the EC2 page.
• Click on “Images” in the left tab, then select “AMI Catalog.”
• Search for “ubuntu (x86_64).”
• Choose the “ubuntu 18.04 LTS” AMI (Free Tier).

 

2. Launch the Instance:

• Click “Continue.”
• On the “Launch an instance” page:
• Name and Tags:
  • Name your instance (e.g., “ubuntu-base-os”).
• Application and OS Images (AMI):
  • Use the previously selected Ubuntu image.
• Instance Type:
  • Choose “t2.micro.”
• Key Pair (Login):
  • Select the “jenkins” key pair created earlier.
• Network Settings:
  • Use default VPC and subnet settings.
  • Enable auto-assign public IP.
  • Select the existing security group (“default”) configured with SSH port.
• Configure Storage:
  • Set storage to 1 x 10 GiB (io1).
• Advanced Details:
  • No additional configurations needed.
• Summary:
  • Review settings and click “Launch instance.”

 

3. Retrieve Public IP:

• Go back to the EC2 page.
• Wait for the instance to be in a running state.
• Note down the public IP address.

 

4. SSH Login:

• On your local macOS terminal:
• Navigate to the directory where “jenkins.pem” is located.
• Run: $ chmod 400 jenkins.pem
• SSH into the instance:

$ ssh ubuntu@52.66.233.40 -i jenkins.pem

• Type “yes” at the prompt.
• You’re now logged in as the “ubuntu” user.

 

5. Create User “jenkins”:

• For security reasons, we’ll use a separate user:

$ sudo adduser jenkins

• Follow the prompts to set a password and other details.

Step 2: Creating and Configuring the “jenkins” User

1. Login as Root:

• Open a terminal and run:

$ sudo su

 

2. Create the “jenkins” User:

• Create the user with a strong password (e.g., “12345678”):

# adduser jenkins

• Provide necessary details or press <enter> for defaults.

 

3. Set Up SSH Access for “jenkins”:

• Switch to the “jenkins” user:

# sudo su – jenkins

• Create an SSH directory and set permissions:

$ cd ~
$ mkdir .ssh
$ chmod 700 .ssh

• Edit the authorized_keys file (paste your ssh-keygen output from Part 1):

$ vi .ssh/authorized_keys

Set permissions for the authorized_keys file:

$ chmod 600 .ssh/authorized_keys

 

4. Add “jenkins” to Admin Group:

• Exit the EC2 instance.
• Log in as the “jenkins” user:

$ sudo usermod -aG adm jenkins

 

5. Modify “ubuntu” User’s UID and GID:

• Log in as the “jenkins” user:

$ sudo usermod -u 2000 ubuntu
$ sudo groupmod -g 2000 ubuntu

• Exit and log in again as the “ubuntu” user:

$ sudo usermod -u 1000 jenkins
$ sudo groupmod -g 1000 jenkins

 

6. Ready for Installation:

• Going forward, perform all installation and configuration tasks using the “jenkins” user.

Step 3: Creating an AMI for the Base OS

1. Create an AMI:

• Navigate to the EC2 page.
• Click on the instance you want to create an AMI from.
• Go to the “Actions” tab, then select “Image and template” > “Create image.”

 

2. Configure the Image:

• In the new window:
  • Image Name:
    • Provide a suitable name (e.g., “ubuntu-base-image”).
• Image Description:
  • Add a brief description (e.g., “Base OS for Ubuntu”).
• Click “Create image.”

 

3. Completion:

• The process generates an AMI that you can use for future Ubuntu base OS operations.