day3.txt

Day3
====
1.Docker Image Creation
2.Docker Container Linking
3.Docker Compose
4.docker volumes

Creating the Images
====================

1.From running Containers
=========================
docker run --name p-apache -d -p 9999:80 httpd

docker exec -it p-apache bash

echo  "<h1>Hello Welcome To Custom Apache Image</h1>" >  /usr/local/apache2/htdocs/index.html

docker commit -m 'Index File Content Changed' -a 'Pradeep Chinchole <pradeepch82@gmail.com>' p-apache pradeepch82/apache:1.1

docker login
username :pradeepch82@gmail.com
password :password

docker push pradeepch82/apache:1.1

docker run --name b-apache -p 4545:80 -d pradeepch82/apache:1.1


2.Using Docker File 
====================

Dockerfile : 

A text file with instructions to build image
Automation of Docker Image Creation

FROM           :Base Image    
MAINTAINER     :Author Name
ENV            :Environment variable
ADD            :ADD the files while buiding the image
RUN            :To install libraries/packages (executed while building the image)
ENTRYPOINT     :Executed at run time and we can not override the commands
CMD            :Executed at run time and we can override by passing command line argument


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

Example  :Dockerfile

FROM ubuntu
MAINTAINER Pradeep Chinchole <pradeepch82@gmail.com>
RUN apt-get update

CMD ["echo", "Hello World..! from my first docker iamge1"]
CMD ["echo", "Hello World..! from my first docker iamge2"]
CMD ["echo", "Hello World..! from my first docker iamge3"]
CMD ["echo", "Hello World..! from my first docker iamge4"]

COMMANDS
: docker build directoryOfDocekrfile
: docker build -t ImageName:Tag directoryOfDocekrfile
: docker run imageid

docker build -t pradeepch82/pvc-ubuntu:1.1 .

docker run pradeepch82/pvc-ubuntu:1.1 .


Docker file for MYSQL
======================
# Derived from official mysql image (our base image)
FROM mysql
# Add a database
ENV MYSQL_DATABASE company
ENV MYSQL_ROOT_PASSWORD admin
ENV MYSQL_USER pradeep
ENV MYSQL_PASSWORD pradeep
# Add the content of the sql-scripts/ directory to your image
# All scripts in docker-entrypoint-initdb.d/ are automatically
# executed during container startup
ADD script.sql /docker-entrypoint-initdb.d/


script.sql
===========
use company;
create table employee(id int primary key,name text,salary double);
insert into employee values(101,'RAM',10000.00);
insert into employee values(102,'RAHIM',20000.00);
insert into employee values(103,'DAVID',30000.00);
insert into employee values(104,'PRADEEP',40000.00);


docker build -t pradeepch82/pvc-mysql:1.1






https://www.javatpoint.com/docker-java-example
https://www.javatpoint.com/docker-php-example
https://www.javatpoint.com/docker-phython-example
https://www.javatpoint.com/docker-scala-example
https://www.javatpoint.com/docker-perl-example
https://www.javatpoint.com/docker-ruby-example




Linking the containers (mysql with WordPress)
==================================================

docker network create p-network

docker run --name p-mysql --network p-network -e MYSQL_ROOT_PASSWORD=admin -e MYSQL_DATABASE=wordpress  -d mysql:5.7

docker run --name p-wordpress --network p-network --link p-mysql -e WORDPRESS_DB_HOST=p-mysql:3306 -e WORDPRESS_DB_USER=root -e WORDPRESS_DB_PASSWORD=admin -e WORDPRESS_DB_NAME=wordpress  -p 1111:80 -d wordpress


Open browser: http://hostname:1111


docker stop p-wordpress p-mysql

docker rm   p-wordpress p-mysql

docker network rm p-network


Linking the containers (mysql with WordPress) using docker-compose
====================================================================

docker-compose.yml
=====================
version: '3.3'
services:
   db:
     image: mysql:5.7
     volumes:
       - db_data:/var/lib/mysql
     restart: always
     environment:
       MYSQL_ROOT_PASSWORD: somewordpress
       MYSQL_DATABASE: wordpress
       MYSQL_USER: wordpress
       MYSQL_PASSWORD: wordpress

   wordpress:
     depends_on:
       - db
     image: wordpress:latest
     ports:
       - "8000:80"
     restart: always
     environment:
       WORDPRESS_DB_HOST: db:3306
       WORDPRESS_DB_USER: wordpress
       WORDPRESS_DB_PASSWORD: wordpress
       WORDPRESS_DB_NAME: wordpress
volumes:
    db_data: {}




docker-compose up -d
docker-compose --scale db=4
docker-compose down


Docker Volumes
===============
1. What are Volumes
2. How to create / list / delete volumes
3. How to attach volume to a container
4. How to share volume among containers
5. What are bind mounts

Volumes are the preferred mechanism for persisting data generated by and used by Docker containers


docker volume  //get information
docker volume create
docker volume ls
docker volume inspect
docker volume rm
docker volume prune


Use of Volumes
===================
Decoupling container from storage
Share volume (storage/data) among different containers
Attach volume to container
On deleting container volume does not delete

Commands

For MySQL
============

docker volume create myvol

docker run --name a-mysql -v myvol:/var/lib/mysql  -e MYSQL_ROOT_PASSWORD=root -e MYSQL_DATABASE=company -d mysql:5.7

docker run --name b-mysql -v myvol:/var/lib/mysql  -e MYSQL_ROOT_PASSWORD=root -d mysql:5.7

 
docker exec -it b-mysql bash

root@9e2af2d31b2d:/# mysql -uroot -proot


For Jenkins
============

docker run --name MyJenkins1 -v myvol2:/var/jenkins_home -d -p 8080:8080 -p 50000:50000 jenkins

docker run --name MyJenkins2 -v myvol2:/var/jenkins_home -d -p 9090:8080 -p 60000:50000 jenkins



http://hostname:8080

Default username :admin
Password :Copy from MyJenkins Container logs (docker logs MyJenkins1)

http://hostname:9090