Steps for SSH key generation on Linux, macOS, or Unix.

From the terminal on your local machine, run the ssh-keygen command, and follow the directions to save the file to the .ssh directory for your profile. 

Note: the keys can be used for SSH connection to AWS, Git etc..

$ ssh-keygen

Generating public/private rsa key pair.
Enter file in which to save the key (/home/user-name/.ssh/id_rsa): Type /home/your-user-name/.ssh/ and a file name here, for example /home/your-user-name/.ssh/mykey_rsa

Enter passphrase (empty for no passphrase): <Type a passphrase, and then press Enter>
Enter same passphrase again: <Type the passphrase again, and then press Enter>

Your identification has been saved in /home/user-name/.ssh/mykey_rsa.
Your public key has been saved in /home/user-name/.ssh/mykey.pub.
The key fingerprint is:
45:63:d5:99:0e:99:73:50:5e:d4:b3:2d:86:4a:2c:14 user-name@client-name
The key's randomart image is:
+--[ RSA 2048]----+
|        E.+.o*.++|
|        .o .=.=o.|
|       . ..  *. +|
|        ..o . +..|
|        So . . . |
|          .      |
|                 |
|                 |
|                 |
  1. This generates:
    • The mykey_rsa file, which is the private key file.
    • The mykey_rsa.pub file, which is the public key file.
  2. Run the following command to display the value of the public key file (mykey_rsa.pub):
cat ~/.ssh/mykey_rsa.pub

Should looks similar to the following:

DgYDVQQHEwdTZWF0dGxlMQ8wDQYDVQQKEwZBbWF6b24xFDAS=EXAMPLE user-name@ip-192-0-2-137

Machine Learning

What is Machine Learning

Tom Mitchell in 1998 provided a modern definition: “A computer program is said to learn from experience E with respect to some tasks T and some performance measure P, if its performance on T, as measured by P, improves with experience E”.

Remember ETP:

Learn from Experience E in doing the task T measured by improvement in performance P

Example of playing checkers

  • E: the experience of playing many games of checkers
  • T: the task of playing checkers
  • P: the probability that the program will win the next game.
Selective Focus Photography of Two Danbo and Star Wars Stormtrooper Robot Toys

Put or Post

  • GET is used to fetch the resource/content.
  • PUT is used to modify and update a resource.
  • POST is used to create a resource, or overwrite it.


  • GET/PUT for listing and updates
  • POST to insert or Overrite

Microservices Architecture

What is Microservices?

It is an architecture style in which applications are composed from loosely coupled API service with automated and independent life cycles.

  1. Behavior
  2. Reliability
  3. Control
  4. Resilience

What does design practice needs to provide

  • Behavior by
    • Single Capability Focused and
    • Encapsulation

And framework needs to provide

  • Behavior by
    • Independence
  • Reusability by
    • Consumer First
    • Infrastructure Agnostics
  • Control
    • Automation
    • Discoverable
    • Lightweight communication
  • Reliance
    • Highly Resilient and Secure
    • Highly observable