What is makefile and how to use it.

A Makefile is a special file used in Unix and Unix-like operating systems to automate the building and compilation of programs or projects. It contains a set of rules and dependencies that specify how to build a target, typically an executable program or a collection of files.

.SILENT:

all: first second last

# .DEFAULT_GOAL:= last

first:

    echo "hello world"

second:

    echo "hello Gaurav"

last:

    echo "hello world Gaurav"

 

Refer here for more details

Setup Minikube on Windows using WSL

 curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64

sudo install minikube-linux-amd64 /usr/local/bin/minikube

Start a cluster - 

minikube start

Start second cluster -

minikube start -p cluster2

List all minikube cluster running:

minikube profile list

Set second cluster as current profile-

Kubectl:

Set kubectl alias to run kubectl commands for minikube if kubectl is not installed locally:

alias kubectl="minikube kubectl --"

View kubernetes config:

kubectl config view

To access minikube from windows command prompt - 

Update kube config file as per config on WSL running minikube

apiVersion: v1

clusters:

- cluster:

    certificate-authority: \\wsl.localhost\Ubuntu\home\gaugupta\.minikube\ca.crt

    server: https://127.0.0.1:49159

  name: cluster2

- cluster:

    certificate-authority: \\wsl.localhost\Ubuntu\home\gaugupta\.minikube\ca.crt

    server: https://127.0.0.1:49154

  name: minikube

contexts:

- context:

    cluster: cluster2

    user: cluster2

  name: cluster2

- context:

    cluster: minikube

    user: minikube

  name: minikube

current-context: cluster2

kind: Config

preferences: {}

users:

- name: cluster2

  user:

    client-certificate: \\wsl.localhost\Ubuntu\home\gaugupta\.minikube\profiles\cluster2\client.crt

    client-key: \\wsl.localhost\Ubuntu\home\gaugupta\.minikube\profiles\cluster2\client.key

- name: minikube

  user:

    client-certificate: \\wsl.localhost\Ubuntu\home\gaugupta\.minikube\profiles\minikube\client.crt

    client-key: \\wsl.localhost\Ubuntu\home\gaugupta\.minikube\profiles\minikube\client.key

Then

>kubectl config use-context minikube

>kubectl get pods

Setup Docker Engine on Windows using WSL2

Steps to setup docker on Windows 10/11 system without installing Docker Desktop application, which is just a GUI for docker.

First, you need to install WSL (Windows subsystem for Linux) if not already installed -

wsl --install

Note: It will install ubuntu linux as default linux flavour. If you need to check and install any other use below command:

        wsl --list --online

        wsl --install kali-linux

Next, install docker using below commands

# Add Docker's official GPG key:

sudo apt-get update

sudo apt-get install ca-certificates curl gnupg

sudo install -m 0755 -d /etc/apt/keyrings

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg

sudo chmod a+r /etc/apt/keyrings/docker.gpg

# Add the repository to Apt sources:

echo \

  "deb [arch="$(dpkg --print-architecture)" signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \

  "$(. /etc/os-release && echo "$VERSION_CODENAME")" stable" | \

  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

sudo apt-get update

          sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

Last, verify docker is installed and running successfully.

        docker run hello-world

        docker run docker/getting-started

Verify all processes running on ubuntu machine.

Finally, to view and setup getting-started with docker code, download and install git using :

    sudo apt-get install git

Ref - https://medium.com/geekculture/run-docker-in-windows-10-11-wsl-without-docker-desktop-a2a7eb90556d

Ref - https://docs.docker.com/engine/install/ubuntu/#installation-methods

Setup MongoDB on Docker

Setup MongoDB community server as a single node.

$ docker pull mongodb/mongodb-community-server

Verify MongoDB image is downloaded successfully: 

$ docker images

Run docker image

$ docker run --name mongo -p 27017:27017 -d mongodb/mongodb-community-server:latest

Setup MongoDB 3 node cluster on docker

The steps to create a docker cluster are as follows.

1. Create a Docker network.

            $ docker network create mongoCluster

1. Start three instances of MongoDB.

docker run -d --rm -p 27017:27017 --name mongo1 --network mongoCluster mongo mongod --replSet myReplicaSet --bind_ip localhost,mongo1

docker run -d --rm -p 27018:27017 --name mongo2 --network mongoCluster mongo mongod --replSet myReplicaSet --bind_ip localhost,mongo2

 

docker run -d --rm -p 27019:27017 --name mongo3 --network mongoCluster mongo mongod --replSet myReplicaSet --bind_ip localhost,mongo3

1. Initiate the Replica Set.

docker exec -it mongo1 mongosh --eval "rs.initiate({

 _id: \"myReplicaSet\",

 members: [

   {_id: 0, host: \"mongo1\"},

   {_id: 1, host: \"mongo2\"},

   {_id: 2, host: \"mongo3\"}

 ]

})"

docker exec -it mongo1 mongosh --eval "rs.status()"

Detailed information on Replica set configuration can be found here.

Once you have a MongoDB cluster up and running, you will be able to experiment with it.

Ref: https://www.mongodb.com/compatibility/deploying-a-mongodb-cluster-with-docker

Using Docker Compose -

docker-compose -f config/docker-compose.yaml up -d


More details on cluster setup can be learned from Mongodb University here.