Docker Exercise

What are docker image and docker containers?

Docker Images are Templates used to create Docker Container

Container is a running instance of an image

Basic Commands

Version

docker -v

Docker Images

List of Images

docker images

List of commands for images

docker images --help

Pull an image

docker pull ubuntu

Filtering images

docker images -f "dangling=true"

Dangling images are images which are associated with any containers

Running an image

docker run --name MyUbuntu -it ubuntu bash

Inspecting an image

docker inspect ubuntu

Remove an Image

docker rmi ubuntu

Docker Containers

Show the list of running containers

docker ps

Show the list of all containers

docker ps -a

Start a container

docker start <container name/id>

Stop a container

docker stop <container name/id>

Pause a container

docker pause <container name/id>

Resume a container

docker unpause <container name/id>

Displaying stats

docker stats <container name/id>

Remove a container

docker rm <container name/id>

Get the history of an image

docker history <image name/id>

Dockerfile

What is a dockerfile?

A Dockerfile is a simple text file with instruction to build images

Automation of docker image creation

How to create a Dockerfile?

Step 1 : Create a file named Dockerfile
Step 2 : Add instructions in Dockerfile
Step 3 : Build Dockerfile to create image
Step 4 : Run image to create container

Dockerfile example

FROM ubuntu

MAINTAINER ramanuj das <ramanujds9@gmail.com> 

RUN  apt-get update

CMD ["echo", "Hello World...! Image Running.."]

How to build image from Dockerfile?

docker build -t myUbuntu:1.0 .

#t flag is used for tagging an image

Running the image:

docker run <image id>

Docker Volume

Docker volumes are used for decoupling container from storage

Command to create a docker volume:

docker volume create myVolume1

Running jenkins with the volume:

docker run --name myJenkins1 -v myVolume1:/var/jenkins_home -p 9000:8080 -p 50000:50000 jenkins

Docker Mysql + SpringBoot

How to run MySql on Docker -

 docker pull mysql
 docker run -d -e MYSQL_ROOT_PASSWORD=password -e MYSQL_DATABASE=mydb -e MYSQL_USER=docker -e MYSQL_PASSWORD=password -p 3308:3306 --name mysql mysql

Running Spring Boot 3 Projects on Docker

Creating image through Spring Boot -
```
mvn spring-boot:build-image
```
Running docker image -

Link Based Communication -

docker container run -p 5000:5000 -e RDS_HOSTNAME=mysql -e RDS_PORT=3306 --link=mysql --name book-store book-store-server:0.0.1-SNAPSHOT

Host Based Communication -

  docker container run -p 5000:5000 --network=host book-store-server:0.0.1-SNAPSHOT

Custom Network
- Creating a Custom Network :

docker network create book-store-mysql-network

Running Mysql Container on that network -

docker run -d -e MYSQL_ROOT_PASSWORD=password -e MYSQL_DATABASE=mydb -e MYSQL_USER=docker -e MYSQL_PASSWORD=password -p 3308:3306 --name mysql --network=book-store-mysql-network mysql

Running book-store on that network -

docker container run -p 5000:5000 -e RDS_HOSTNAME=mysql -e RDS_PORT=3306 --network=book-store-mysql-network -d --name book-store book-store-server:0.0.1-SNAPSHOT

Using Docker volume to Persist Data -

docker run -d -e MYSQL_ROOT_PASSWORD=password -e MYSQL_DATABASE=mydb -e MYSQL_USER=docker -e MYSQL_PASSWORD=password -p 3308:3306 --name mysql --volume mysql-db-volume:/var/lib/mysql --network=book-store-mysql-network mysql

Running Angular Application

How to run an Angular Application in Docker?

Build the Angular App

ng build [app-name] --prod=true

Create a Dockerfile in the root directory

FROM nginx
COPY dist/[app-name] /usr/share/nginx/html

Build the image

docker build -t [image-name] .

Run the image

docker run -p 80:80  [image-name]

Docker Compose

What is Docker compose?

Tool for defining and running musti-container Docker application
It uses yaml file to configure application services(docker-compose.yml)
Can start all services with a single command
Can scale up selected services when required

Steps

Step 1 : Create the docker compose file (docker-compose.yml)
Step 2 : Check the validity of the file using command:

docker-compose config

Step 3 : Run docker-compose yml file using command:

docker-compose up

Step 4 : Stop docker-compose using command:

docker-compose down

docker-compose.yml exmaple:

version: '3'

services:
    web:
        image: nginx
        ports:
            - 9090:80
    database:
        image: redis

How to use scaling?

docker-compose up -d --scale database=4

Running Fullstack Application using Docker-Compose

version: '3.7'

services:

  book-store-frontend:
    image: book-store-client-app 
    #build:
      #context: .
      #dockerfile: Dockerfile
    ports:
      - "4200:80"
    restart: always
    depends_on: # Start the depends_on first
      - book-store-spring-boot 
    networks:
      - book-store-app-network

  book-store-spring-boot:
    image: book-store-server:0.0.1-SNAPSHOT
    #build:
      #context: .
      #dockerfile: Dockerfile
    ports:
      - "5000:5000"
    restart: always
    # depends_on: # Start the depends_on first
    #   - mysql 
    environment:
      RDS_HOSTNAME: mysql
      RDS_PORT: 3306
      RDS_DB_NAME: mydb
      RDS_USERNAME: docker
      RDS_PASSWORD: password
    networks:
      - book-store-app-network

  mysql:
    image: mysql
    command: --default-authentication-plugin=mysql_native_password
    ports:
      - "3308:3306"
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: password
      MYSQL_USER: docker
      MYSQL_PASSWORD: password
      MYSQL_DATABASE: mydb
      MYSQL_ROOT_HOST: 192.168.0.48/255.255.255.248
    # volumes:
    #   - mysql-db-volume:/var/lib/mysql
    networks:
      - book-store-app-network
      # network:
      #   ipv4_address: 172.20.0.2
  
# Volumes
# volumes: 
#   mysql-db-volume:

networks:
  book-store-app-network:

Some useful Docker Compose Commands

Docker-compose Configuration

docker-compose config

Docker-Compose Images Used

docker-compose images

Docker-Compose Container Used

docker-compose ps

Docker-Compose Pause, Resume, Stop, Kill

docker-compose pause
docker-compose unpause
docker-compose stop
docker-compose kill

Docker-Compose Events

docker-compose events

Build Images from Dockerfile

docker-compose build

Running Microservices on Docker

Harshverm776 / docker-exercise