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Date: 11-Nov-2024
Topic : Docker Introduction
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==========================
Application Architecture
==========================

=> Application will be developed with 3 layers

		1) Frontend (User interface)

		2) Backend (business logic)

		3) Database (storage)

=======================
Application Tech Stack
=======================

Project-1 : Angular + Java + Oracle DB

Project-2 : React JS + Java + MySQL DB

Project-3 : React JS + Node JS + Mongo DB

Project-4 : Angular + .Net + SQL Server

Project-4 : React JS + Python + MySQL DB



If we want to run application in any machine then we have to install all the required softwares with proper version compatability.

Ex: Angular 17v, Java 11v, Tomcat 9.0v, MySQL 8.5v

Note: If we do any mistake in s/w installations then application can't execute.

=> If we want to test our application in multiple machines then installing all the required softwares in all those machines is time taking process and risky process.

=> To simplify application execution process in any machine we will use Docker.

===============
What is Docker
===============

=> It is free and open source s/w.

=> Docker is used for containerization.

Note: Containerization is the process of packaging "application code + application dependencies as single unit for execution".

=> Using docker, we can run our application in machine without bothering about softwares installation.

Note : Docker will take care of s/w installation required to run our application.


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Date: 12-Nov-2024
Topic : Docker Architecture + Docker Commands
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====================
Docker Architecture
====================

1) Dockerfile
2) Docker Image
3) Docker Container
4) Docker Hub

=> Dockerfile contains set of instructions to build docker image.

=> Docker Image is a package which contains "code + dependencies" for execution.

Note: When we run Docker Image then Docker container will be created.

=> Docker Container is a virtual machine, in that our app will execute.

=> Docker Hub is a registry which is used to store our docker images.

==============
Docker Setup
==============

https://github.com/ashokitschool/DevOps-Documents/blob/main/02-Docker-Setup.md

=================
Docker Commands
=================

docker images : Display list of images available in our machine

docker ps : Display Running containers

docker ps -a : Display stopped containers

docker rmi <image-id> : Remove image from machine

docker rm <container-id> : Remove stopped container

docker pull <image-name> :  Download docker image 

docker run <image-name> : To create docker container

docker stop <container-id> : Stop the running container
 
docker start <container-id> : Start the container which got stopped

docker system prune -a : Remove stopped containers + un-used images


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Date: 13-Nov-2024
Topic : Docker Containers
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############  1) What is detached mode ?  ###########

=> It is used to created in background. It will allow us to run commands in terminal.

	Ex : docker run -d ashokit/spring-boot-rest-api

############  2) What is port mapping ? ###############

=> It is used to map container port number to host machine port number

=> Once we perform port mapping then we can access our application which is running inside the container by using host machine public address.


Syntax :   docker run -d -p <host-port:container-port> <image-name>


Ex : 	docker run -d -p 9090:9090 ashokit/spring-boot-rest-api

Note: To access our application we need to enable HOST PoRT in security group inbound rules.

		App URL : http://public-ip:host-port/welcome/raja

Note: If we are using docker in windows machine instead of public we can use localhost in the url.

============
Dockerfile
============

=> Dockerfile contains set of instructions to create docker image.

=> In Dockerfile we will add below details

		a) Application Dependencies

		b) Application Execution Process

=> To write Dockerfile we will use below keywords

		1) FROM
		2) MAINTAINER
		3) RUN
		4) CMD
		5) COPY
		6) ADD
		7) WORKDIR
		8) EXPOSE
		9) ENTRYPOINT
		10) USER

Note: Dockerfile will be saved with a name "Dockerfile" (no extension).


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Date: 14-Nov-2024
Topic : Docker File
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## FROM : It is used to specify base image to create our image.

Ex:

FROM openjdk:17

FROM python:3.9

FROM tomcat:9.0

FROM node:latest

Note: Base images we can find in docker hub.

## MAINTAINER : It is used to specify author of dockerfile (optional)

Ex: MAINTAINER Ashok(13247979)

## RUN : It is used to specify instructions which will execute when docker image is getting created.

Ex: 

RUN git clone <repo>

RUN mvn clean package

Note: We can write multiple RUN instructions in dockerfile, they will execute in sequential order.

## CMD : It is used to specify instructions which will execute when docker container is getting created.

Note: CMD is used to run our application inside container.

Note: We can write multiple CMD instructions in dockerfile, but docker will execute only last CMD instruction.

## ENTRYPOINT : It is used to execute instructions while container getting created.

Ex: 

ENTRYPOINT [java -jar app.jar]

Note: CMD instructions we can override while running docker image where as ENTRYPOINT instructions we can't override.

## COPY : It is used to copy the files from HOST machine to container machine.

Ex: 

COPY target/app.war /usr/local/tomcat/webapps/app.war

## ADD : It is used to copy the files from HOST machine to container machine.

Ex:

ADD <file-http-url> <destination-path>


## WORKDIR : It is used to set working directory while executing dockerfile.

Ex:  WORKDIR /usr/app/

## EXPOSE : It is used to specify container running on which port number. It is only used for readability and it is optional to mention in dockerfile.

EX: 

EXPOSE 9090

## USER : It is used to specify with which user account we want to use to execute dockerfile instructions.

Ex: 

USER devopsuser

===================

FROM ubuntu

MAINTAINER Ashok

RUN echo 'hi - run-1'

RUN echo 'hello - run-2'

CMD echo 'Hi - cmd1'

CMD echo 'hello - cmd2'

========================

$ docker images

$ docker system prune -a

$ docker build -t <image-name> .

Ex : docker build -t <dockerhub-uname/demo1> .

$ docker images

$ docker run <image-name/image-id>

$ docker login

Note: Need to enter docker hub account credentials.

$ docker push <dockerhub-uname/demo1>


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Date: 15-Nov-2024
Topic : Writing Dockerfile
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==========================================================
Dockerizing Java web application (without springboot)
===========================================================

=> Java web applications (without springboot) will be packaged as war file.

=> To run war file we need a webserver like apache Tomcat.

=> Inside tomcat server "webapps" folder will be available to deploy war files.

Note: We need to copy project war file to tomcat server webapps folder for execution.

------------------------------------------------------------------------

FROM tomcat:latest

EXPOSE 8080

COPY target/maven-web-app.war  /usr/local/tomcat/webapps/

-------------------------------------------------------------------------


@@ Maven Web App Git Repo : https://github.com/ashokitschool/maven-web-app.git


Note: If you are using docker in linux vm then install git and maven softwares

$ sudo yum install git -y
$ sudo yum install maven -y

# clone git repo
git clone https://github.com/ashokitschool/maven-web-app.git

# Perform maven build
cd maven-web-app
mvn clean package

Note: After maven package it will generate war file inside target directory.

# check targer directory content
ls -l target

# create docker image
docker build -t app1 .

# Check docker images
docker images

# Run container
docker run -d -p 8080:8080 app1

Note: Enable 8080 port number in security group inbound rules.

# Access application in browser

	URL : http://public-ip:8080/maven-web-app/


=========================================
Dockerizing Java Spring Boot Application
=========================================

=> Every SpringBoot application will be packaged as jar file only

=> To run spring boot application we need to execute jar file.

	Syntax : java -jar <jar-file-name>

Note: When we run springboot application jar file then springboot will start tomcat server with 8080 port number (embedded tomcat server).

=============== Dockerfile for Spring Boot Application =============

FROM openjdk:17

MAINTAINER Ashok

COPY target/app.jar /usr/app/

WORKDIR /usr/app/

EXPOSE 8080

ENTRYPOINT ["java", "-jar", "app.jar"]

====================================================================

## Java Spring Boot App Git Repo : https://github.com/ashokitschool/spring-boot-docker-app.git

$ git clone https://github.com/ashokitschool/spring-boot-docker-app.git

$ cd spring-boot-docker-app

$ mvn clean package

$ ls -l target

$ docker build -t sb-app .

$ docker run -d -p 8080:8080 sb-app

Note: Once container created check logs of container

$ docker logs <container-id>

Note: Access our application using host-vm public and host port

		URL : http://localhost:host-port/


=====================================
Dockerize Python Flask Application
=====================================

=> Python is a scripting language

=> We don't need any build tool for python app

=> Directley we can run python programs

	Ex : python app.py

=> Flask is a python library which is to develop rest apis in python.	

=> To download flask library we will use 'python pip software'

Note: We will configure dependencies in "requirements.txt"

=============== Dockerfile for Python Flask App =================

FROM python:3.6

MAINTAINER Ashok

COPY . /usr/app/

WORKDIR /usr/app/

RUN pip install -r requirements.txt

EXPOSE 5000

ENTRYPOINT ["python", "app.py"]

===================================================================

Python App Git Repo : https://github.com/ashokitschool/python-flask-docker-app.git

$ git clone https://github.com/ashokitschool/python-flask-docker-app.git

$ cd python-flask-docker-app

$ docker build -t <img-name> .

$ docker run -d -p 5000:5000 <img-name>

$ docker ps

Note: Enable 5000 port in security group inbound rules.

=> Access application with URL

			URL : http://public-ip:host-port/



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Date: 19-Nov-2024
Topic : Docker Projects
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=================================
Dockerizing Angular application
=================================

=> Angular is a frontend framework

=> Angular is used to develop frontend of the applications

Note: Angular developed by google company.

=> We will use Node Package Manager( NPM ) to build angular applications

Note: When we build angular app it will generate "dist" folder for deployment

=> To run angular app we can copy "dist" folder data to "Nginx" server.


--------------

FROM node:18 AS build

WORKDIR /app

COPY package*.json ./

RUN npm install

COPY . .

RUN npm run build --prod

FROM nginx:alpine

COPY --from=build /app/dist/angular_docker_app /usr/share/nginx/html

EXPOSE 80

--------------------

git clone https://github.com/ashokitschool/angular_docker_app.git

cd angular_docker_app

docker build -t ngapp .

docker images

docker run -d -p 80:80 ngapp

Note:  Enable 80 port number in security group inbound rules.

=> Access application in browser using docker-server public ip address

		URL : http://13.200.252.152/

=================================
Dockerizing React JS application
=================================

=> React JS is a Java Script library it is used to develop frontend of the applications.

Note: React JS developed by facebook.

=> We will use Node Package Manager( NPM ) to build react applications

Note: When we build react app it will generate "build" folder for deployment.

=> To run angular app we can copy "build" folder data to "Nginx" server.

--------------

FROM node:18 AS build

WORKDIR /app

COPY package*.json ./

RUN npm install

COPY . .

RUN npm run build --prod

FROM nginx:alpine

COPY --from=build app/build /usr/share/nginx/html

EXPOSE 80

--------------------

git clone https://github.com/ashokitschool/ReactJS_Docker_App.git

cd ReactJS_Docker_App

docker build -t reactapp .

docker images

docker run -d -p 80:80 reactapp

Note:  Enable 80 port number in security group inbound rules.

=> Access application in browser using docker-server public ip address

		URL : http://13.200.252.152/

================
Docker Network
================

=> Network is all about communication

=> Docker network is used to provide isolated network for containers.

=> If we want to access one docker container from another docker container then those 2 containers should run on the same network.

=> By default we have 3 networks in the docker

		1) bridge
		2) host
		3) none

=> Bridge network is used to run standalone containers. It will assign one IP address for the container. It is the default network used by docker container.

=> Host network is used to run standalone containers. This will not assign any ip address for the container.

=> None means no network will be provided.


# display docker networks
docker network ls

# create docker network
docker network create ashokit-nw

# inspect docker network
docker network inspect ashokit-nw

# run docker container with custom network
docker run -d -p 8080:8080 --network ashokit-nw ashokit/java-web-app

# delete network
docker network rm ashokit-nw

=================
Docker Compose
=================

=> Earlier companies used to develop applications using Monolithic architecture (everything in single application).

=> Now a days companies are using Microservices architecture to develop the applications.

=> Microservices means we will have multiple backend apis and every backend api is a seperate project.

		a) hotels-api
		b) flights-api
		c) trains-api
		d) cabs-api

=> For every backend api seperate dockerfile will be available and we need to create seperate docker image for every api.

=> In order to deploy our application we need to manage multiple containers.

=> When we have multiple containers then managing them will be difficult (create/start/stop/re-start).

=> To overcome these management problems we will use Docker Compose.

=> Docker Compose is used to manage multi-container based applications.

=> using docker-compose with single command we can "create/stop/start/delete" multiple containers.

=> which containers should be managed by docker-compose we will configure that information in docker-compose.yml file.

=============================
What is docker-compose.yml ?
=============================

=> It is used to specify containers information.

=> The default file name is "docker-compose.yml" 

=> docker-compose yml contains 4 sections

	version  : Represents compose yml version

	services : Represents containers information(image, port no)
	
	networks : Represents docker network to run containers
	
	volumes  : Represents storage for containers


=====================
Docker Compose Setup
=====================

https://github.com/ashokitschool/DevOps-Documents/blob/main/03-Docker-Compose-Setup.md

===============================================
Spring Boot with MySQL DB using Docker-Compose
===============================================

version: "3"
services:
  application:
    image: spring-boot-mysql-app
    ports:
      - "8080:8080"
    networks:
      - springboot-db-net
    depends_on:
      - mysqldb
    volumes:
      - /data/springboot-app
    
  mysqldb:
    image: mysql:5.7
    networks:
      - springboot-db-net
    environment:
      - MYSQL_ROOT_PASSWORD=root
      - MYSQL_DATABASE=sbms
    volumes:
      - /data/mysql
networks:
  springboot-db-net:


===============================
Application Execution Process
===============================

# clone git repo
git clone https://github.com/ashokitschool/spring-boot-mysql-docker-compose.git

#go inside project directory
cd spring-boot-mysql-docker-compose

# build project
mvn clean package

# create docker image
docker build -t spring-boot-mysql-app .

# check docker images
docker images

# create containers using docker-compose
docker-compose up -d

# stop containers using docker-compose
docker-compose stop

# start containers using docker-compose
docker-compose start

# delete containers using docker-compose
docker-compose down

=============================================
Stateless Containers vs Statefull Containers
=============================================

Stateless Container : Data will be deleted after container deletion

Statefull Container : Data will be available permanentley.

Note: Docker containers are by default stateless.

Note: In above example when we delete and re-create containers we lost data that we inserted in application. This is not accepted in the real-time.

=> In order to maintain containers data we will use Docker Volumes concept.

=> Using Docker Volumes concept, we can make docker container as statefull container.

=====================================
Making docker container as stateful
=====================================


=> Map ".app" directory to database container as a bind mount volume.


version: "3"
services:
  application:
    image: spring-boot-mysql-app
    ports:
      - "8080:8080"
    networks:
      - springboot-db-net
    depends_on:
      - mysqldb
    volumes:
      - /data/springboot-app
    
  mysqldb:
    image: mysql:5.7
    networks:
      - springboot-db-net
    environment:
      - MYSQL_ROOT_PASSWORD=root
      - MYSQL_DATABASE=sbms
    volumes:
      - .app:/var/lib/mysql
networks:
  springboot-db-net:



==========
Summary
==========

1) What are the challenges in app deployment process

2) Containerization

3) Docker Introduction

4) Docker Architecture

5) Docker Setup in windows & linux

6) Docker Registry (docker hub)

7) Docker Images

8) Docker Containers

9) Dockerfile

10) Dockerize java web app with tomcat

11) Dockerize java springboot app

12) Dockerize python flask app

13) Dockerize angular app

14) Dockerize react app

15) Docker Network

16) Docker Compose

17) Docker Volumes

18) Docker Swarm