===========================
Application Architecture
===========================

1) Frontend : User Interface (UI)

2) Backend : Business logic

3) Database : Storage

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

Frontend : Angular 16v

Backend : Java 17v

Database : MySQL DB Server 8.5

Webserver : Tomcat 9.0


Note: If we want to run our application code, then we need to setup all required dependencies in the machine.

Note: dependencies nothing but the softwares which are required to run our application.

	Ex: java 17 + Angular 16 + MySQL 8.5 + Tomcat server 9.0


Note: If we want to run same application in 100 machines then it is hectic task to setup dependencies and there is a chance of human mistakes.

=> To overcome above problem we will use Docker tool.


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

=> Docker is a free & open source software.

=> Docker is used for containerization.

Note: Containerization means packaging application code + application dependencies as single unit for execution.

=> With the help of docker, we can run our application in any machine.

=> Docker will take care of dependencies installation required for application execution.

=> We can make our application portable using Docker.

Note: Docker is platform independent. We can use docker in windows, linux and mac also.

	
		Docker Container =  application code + application dependencies


=====================
Docker Architecture
=====================

1) Dockerfile

2) Docker Image

3) Docker Registry

4) Docker Container


=> Dockerfile is used to specify where is app code and what dependencies are required for our application execution.

Note: Using dockerfile we will build docker image.

=> Docker image is a package which contains app code and app dependencies.

		Docker Image = app code + app dependencies

=> Docker Registry is used to store docker images.

Note: When we run docker image then docker container will be created. Docker container is a linux virtual machine.

=> Inside Docker Container our application will be executed.

=============================
Install Docker in Linux VM
=============================

Step-1 : Create EC2 VM (amazon linux) & connect with that vm using ssh client

Step-2 : Execute below commands

# Install Docker
sudo yum update -y
sudo yum install docker -y
sudo service docker start

# Add ec2-user user to docker group
sudo usermod -aG docker ec2-user

# Exit from terminal and Connect again
exit

# Verify Docker installation
docker -v



==================
Docker commands
==================

docker images : To display docker images available in our system.

docker pull <image-id/name> : To download docker image from docker hub.

docker rmi <image-id/name> : To delete docker image.

docker run <image-id/name> : TO create/run docker container.

docker ps : To display running docker containers.

docker ps -a : To display running + stopped containers.

docker stop <container-id> : To stop running docker container.

docker start <container-id> : To start docker container which is in stopped state.

docker rm <container-id> : To delete docker container.

# delete stopped containers + unused images + build cache
docker system prune -a

docker build -t <tag-name> . : To build docker image

docker login : To login into docker hub account

docker push <img-name> : To push docker img into docker hub


=======================================================
Running Real-world applications using docker images
=======================================================

docker pull ashokit/spring-boot-rest-api
docker run ashokit/spring-boot-rest-api
docker run -d ashokit/spring-boot-rest-api
docker ps
docker logs <container-id>
docker run -d -p host-port:container-port ashokit/spring-boot-rest-api

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

########### Java App URL : http://public-ip:host-port/welcome/{name}


docker pull ashokit/python-flask-app
docker run -d ashokit/python-flask-app
docker run -d -p 5000:5000 ashokit/python-flask-app

########### Python App URL : http://public-ip:host-port/

Note: Here -d represents detached mode.
Note: Here -p represents port mapping. (host-port:container-port)


Note: host port and container port no need to be same.


Note: Host port number we need to enable in ec2-vm security group inbound rules to allow the traffic.

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

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

		file name : Dockerfile

Note: We will keep Dockerfile inside project directory.

=> 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

=======
FROM
=======

=> It is used specify base image to create our docker image.

Ex: 

FROM tomcat:9.0

FROM openjdk:17	

FROM python:3.3

FROM node:19

FROM mysql:8.5

============
MAINTAINER
============

=> To specify author of Dockerfile (who created/modifed Dockerfile)

Ex:

MAINTAINER Ashok<ashok.b@oracle.com>

Note: It is optional.


========
RUN
========

=> RUN keyword is used to specify instructions (commands) which are required to execute at the time of docker image creation.

Ex:

RUN 'git clone <repo-url>'

RUN 'mvn clean package'

Note: We can specify multiple RUN instructions in Dockerfile and all those will execute in sequential manner.


========
CMD
========

=> CMD keyword is used to specify instructions (commands) which are required to execute at the time of docker container creation.

Ex:

CMD "java -jar <jar-file-name>"

CMD "python app.py"

Note: If we write multiple CMD instructions in dockerfile, docker will execute only last CMD instruction.

=====
COPY
=====

=> COPY instruction is used to copy the files from source to destination.

Note: It is used to copy application code from host machine to container machine.

		Source : HOST Machine

		Destination : Container machine

EX:

COPY target/app.jar	  /usr/app/	

COPY target/webapp.war /usr/app/

COPY app.py        /usr/app/


=====
ADD
=====

=> ADD instruction is used to copy the files from source to destination.


EX:

ADD target/app.jar /usr/app/

ADD <file-url>  /usr/app/


========
WORKDIR
========

=> WORKDIR instruction is used to set / change working directory in container machine.

Ex:

COPY target/app.jar /usr/app/

WORKDIR /usr/app/

CMD "java -jar app.jar"

========
EXPOSE
========

=> EXPOSE instruction is used to specify application is running on which PORT number.

Ex:

EXPOSE 8080


===========
ENTRYPOINT
===========

=> It is used to execute instruction when container is getting created.

Note: ENTRYPOINT is used as alternate for 'CMD' instructions.


CMD "java -jar app.jar"

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

================================================
What is the diff between 'CMD' & 'ENTRYPOINT' ?
=================================================

CMD instructions we can override.

ENTRYPOINT instructions we can't override.

===========
USER
===========

=> It is used to set  user account to execute dockerfile commands

USER 'ashokit'
RUN echo 'hi'


===================================
Dockerizing SpringBoot application
===================================

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

=> Spring Boot is a java framework which is used to develop java based applications.

=> Spring Boot applications will be packaged as a jar file.

=> To run the jar file we will use below command

		Ex: java -jar app.jar

Note: When we run springboot application jar file, internally springboot will use tomcat server as "embedded container" with default port number 8080.

================ Java SpringBoot App Dockerfile ===========

FROM openjdk:17

MAINTAINER "Ashok"

COPY target/sb-app.jar  /usr/app/

WORKDIR /usr/app/

EXPOSE 8080

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

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

1) Clone git repo

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

2) Go inside project directory and perform maven build

cd spring-boot-docker-app
mvn clean package

3) Create docker image

docker build -t ashokit/sb-app .

docker images

4) Create docker container

docker run -d -p 8080:8080 ashokit/sb-app

docker ps

docker logs <container-id>

5) Access application URL in browser

	windows : http://localhost:8080/

	Linux : http://public-ip:8080/


===================================================
Dockerizing Java Web application (no springboot)
===================================================

## App Git Repo : https://github.com/ashokitschool/maven-web-app.git

=> Normal java web apps will be packaged as war file.

Note: war file will be created inside project target directory.

=> To execute that java web application we need to deploy that war file in tomcat server.

=> Inside tomcat server we will have "webapps" folder. It is called as deployment folder. 

=> To run war file we need to keep war file inside tomcat/webapps folder.

================ Dockerfile for Java web application ===============

FROM tomcat:latest

MAINTAINER "Ashok<797979>"

EXPOSE 8080

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

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

1) Clone git repo

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

2) Go inside project directory and perform maven build

cd maven-web-app
mvn clean package

3) Create docker image

docker build -t ashokit/maven-web-app .

docker images

4) Create docker container

docker run -d -p 8080:8080 ashokit/maven-web-app

docker ps

docker logs <container-id>

5) Access application URL in browser

	windows : http://localhost:8080/maven-web-app

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

=================================
Dockerizing Python application 
=================================

=> Python is a general purpose language 

Note: It is also called as scripting language.

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

=> We can run python application code directley like below

	ex: python app.py

=> If we need any libraries for python (Ex: Flask) application development then we will mention them in "requirements.txt" file

Note: We will use "python pip" s/w to download libraries configured in requirements.txt file.


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

FROM python:3.6

COPY . /app/

WORKDIR /app/

EXPOSE 5000

RUN pip install -r requirements.txt

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

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


1) Clone git repo

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

2) Go inside project directory and Create docker image

cd python-flask-docker-app

docker build -t ashokit/py-app .

docker images

3) Create docker container

docker run -d -p 5000:5000 ashokit/py-app

docker ps

docker logs <container-id>

4) Access application URL in browser

	windows : http://localhost:5000/

	Linux : http://public-ip:5000/


================================
How to access docker container
================================

# display docker containers which are in running mode
docker ps

# go inside docker container from linux host
docker exec -it <container-id> /bin/bash

# go inside docker container from windows host
docker exec -it <container-id> sh


========================
Assignments for today
========================

1) Setup Jenkins Server as Docker Container

2) Setup MySQL DB as Docker Container

3) Dockerizing Angular & React application




1) Docker Network
2) Docker Volumes
3) Docker Compose
4) Docker Swarm

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

=> Network is all about communication

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

=> If we run 2 containers under same network then one contianer can communicate with another container.

=> By default we have 3 networks in Docker

			1) bridge
			2) host
			3) none

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

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

=> None means no network will be available.

# 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/maven-web-app

# delete docker network
$ docker network rm ashokit-nw


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

=> Earlier ppl developed projects using Monolithic Architecture 
   (everthing in single app)

Ex : 

	MakeMyTrip app ------> One docker image ----> One Conainer   

=> Now a days projects are developing based on Microservices architecture.

=> Microservices means multiple backend apis will be avialable.

Ex: 
			1) hotels-api
			2) flights-api
			3) trains-api
			4) cabs-api

=> For every API we need to create seperate container.

Note: When we have multiple containers like this, management will become very 
difficult (create / stop / start)

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

=> Docker Compose is used to manage Multi - Container Based applications.

=> In docker-compose, using single command we can create / stop / start multiple containers at a time.


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

=> docker-compose.yml file is used to specify containers information.

=> The default file name is docker-compose.yml (we can change it).

=> docker-compose.yml file contains below 4 sections.

	version : It represents compose yml version.

	services : It represents containers info (image-name, port-mapping).

	networks : It represents network to run our containers.

	volumes : Represents containers storage location.


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

# install docker compose
sudo curl -L "https://github.com/docker/compose/releases/download/1.24.0/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
sudo chmod +x /usr/local/bin/docker-compose

# Check docker compose is installed or not
$ docker-compose --version


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

=> I want to deploy springboot application with MySQl DB
	
	a) MySQL DB will run in one container

	b) SpringBoot-App will run in another container

Note-1: SpringBoot application should connect with MySQl DB. That means app container depends on DB Container.	

Note-2: As we need containers communication those 2 containers should run on same network.

=> Below is the "docker-compose.yml" to manage springboot-app with mysql-db deployment.

---
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 using maven
mvn clean package

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

# check docker images
docker images

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

# check docker containers running
docker-compose ps

# stop docker containers running
docker-compose stop

# start docker containers which are stopped
docker-compose start

# delete docker containers using docker-compose
docker-compose down

====================================
Stateful Vs Stateless Containers
====================================

Stateless Container : Data will be deleted after container deletion.

Statefull Container : Data will be available permanently even after container deletion.

Note: Docker containers are stateless by default.

Note: In spring-boot-mysql app, we are using "mysqldb" as docker container to store application data. When we re-create containers db also got recreated hence we lost data (this is not accepted in realtime).

=> To maintain data permanently, we need to make docker container as statefull.

=> To make container as statefull, we need to use Docker volumes concept.


================
Docker Volumes
================

=> Volumes are used to persist data which is generated by docker container.

=> Volumes are used to avoid data loss.

=> Using volumes we can make container as statefull.


=================================
Making docker container stateful
=================================
---
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:
  ...


=> Once we execute above docker-compose yml it will create containers and it will map MySQl DB container data to .app directory.

=> We can check container data in .app directory

		ls -la  .app  


=============
Docker Swarm
=============		

=> It is an Orchestration platform.

=> Orchestration means Managing the process (containers).

=> Using Docker swarm we will setup Docker cluster

Note: Cluster means group of servers.


============================
Docker Swarm Cluster Setup
============================

-> Create 3 EC2 instances (ubuntu) & install docker in all 3 instances using below 2 commands

curl -fsSL https://get.docker.com -o get-docker.sh
sudo sh get-docker.sh

-> Out of 3 machines we will consider

1  - Master Node
2  - Worker Nodes

Note: Enable 2377 port in security group for Swarm Cluster Communications

-> Connect to Master Machine and execute below command

# Initialize docker swarm cluster
sudo docker swarm init --advertise-addr <private-ip-of-master-node>

Ex : sudo docker swarm init --advertise-addr 172.31.5.176

# Get Join token from master  (this token is used by workers to join with master)
sudo docker swarm join-token worker.

Note: Copy the token and execute in all worker nodes with sudo permission

Ex: sudo docker swarm join --token SWMTKN-1-4pkn4fiwm09haue0v633s6snitq693p1h7d1774c8y0hfl9yz9-8l7vptikm0x29shtkhn0ki8wz 172.31.37.100:2377

Note: With above steps docker swarm cluster is ready.

-> In Docker swarm we need to deploy our application as a service.

sudo docker service create --name maven-web-app -p <host-port:container-port> <imageName>

Ex :  sudo docker service create --name java-web-app -p 8080:8080 ashokit/javawebapp

Note: By default 1 replica will be created


Note: We can access our application using below URL pattern

	URL : http://master-node-public-ip:8080/java-web-app/


# check the services created
$ sudo docker service ls 

# we can scale docker service
$ docker service scale <serviceName>=<no.of.replicas>

# inspect docker service
$ sudo docker service inspect --pretty <service-name>

# see service details
$ sudo docker service ps <service-name>

# Remove one node from swarm cluster
$ sudo docker swarm leave

# remove docker service 
$ sudo docker service rm <service-name>




=========================================
Deploy Angular Application using Docker
========================================

=> Angular is a framework which is used to develop frontend of application (UI)

=> We will use NODE software to build and run Angular application.

=> Angular app libraries will be configured in "package.json" file

=> To download librarires configured we will use 'npm install' command.

=> To build angular application we will use below command

			npm run build --prod

Note: When we run above command 'dist' folder will be generated for deployment.

=> To deploy angular application we will use NGINX webserver.

==================== Dockerfile of Angular App ================================

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/<your-project-name> /usr/share/nginx/html

EXPOSE 80

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

## Step-1 : Clone git repo

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

## Step-2 : Go inside project directory and build docker image

cd angular_docker_app
docker build -t ng-app .

## Step-3 : Run docker container

docker images
docker run -d -p 80:80 ng-app

## Step-4 : Access angular app in browser

		Windows : http://localhost:80/

		Linux : http://public-ip:80/


=========================================
Deploy React Application using Docker
========================================

## Step-1 : Clone git repo

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

## Step-2 : Go inside project directory and build docker image

cd ReactJS_Docker_App
docker build -t react-app .

## Step-3 : Run docker container

docker images
docker run -d -p 80:80 react-app

## Step-4 : Access react-app in browser

		Windows : http://localhost:80/

		Linux : http://public-ip:80/


===========================================
Build + deploy Springboot app using docker
===========================================	

============ Step-1 : Create Dockerfile	with below content ===============

# Stage 1: Build the application
FROM maven:latest AS build

# Set the working directory
WORKDIR /app

# Clone the Git repository
RUN git clone https://github.com/ashokitschool/spring-boot-docker-app.git .

# Build the application
RUN mvn clean package

# Stage 2: Run the application
FROM openjdk:18-jdk-alpine

# Set the working directory
WORKDIR /app

# Copy the built jar file from the build stage
COPY --from=build /app/target/spring-boot-docker-app.jar /app/spring-boot-docker-app.jar

# Expose the port the app runs on
EXPOSE 8080

# Command to run the application
ENTRYPOINT ["java", "-jar", "/app/spring-boot-docker-app.jar"]

============ Step-2 : Build Docker Image ===============

docker build -t sb-app .

============ Step-3 : Run Docker Image ===============

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

============ Step-4 : Access Application in browser ===============

		Windows URL : http://localhost:8080/

		Linux URL : http://public-ip:8080/

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