Docker for Development

 

Making your development workflows better

What is Docker ?

Docker allows you to package an application with all of its dependencies into a standardized unit for software development.

Docker is not a Virtual Machine

VMs vs. Docker

Virtual Machine

Docker

Why docker ?

  • Speed
  • Reproducible environments
  • Portability
  • Flexibility
  • Minimal use of server resources
  • Isolation
  • Lightweight

Why are Docker Containers Lightweight?

Docker Performance

Booting 15 Openstack VMs

Basic Components

 

  1. Containers
  2. Images
  3. Registry
  4. Dockerfiles
  5. Volumes

 

 

 

Docker Image

Container

Base Image (Debian, CentOS, Alpine)

PHP Installed

Composer Installed

Drush added

Extensions installed

Runtime file system (read-write)

Dockerfile

FROM ubuntu

MAINTAINER MajuAnsari <majua@mindfiresolutions.com>

RUN apt-get update \
    && apt-get install -y php php5.6-sqlite php5.6-curl php5.6-gd

COPY configs/php-fpm.conf /etc/php/

WORKDIR /app

COPY . /app

CMD ./run.sh
docker build -t my_first_image .

Docker Hub / Registry

https://hub.docker.com

Public repository of docker images

~100

Official Images

400k+

User Images

https://quay.io/ - private repos

$ docker run -d -p 81:80 nginx:latest tail -f /var/log/nginx/access.log

 

Running a Container

Common arguments:

  • -e    set environment variables
  • --expose    expose ports to linked containers
  • -p    bind ports to host
  • -v    mount a volume
  • -d    run in detached mode
  • lots more...
$ docker run -d -p 81:80 nginx:latest tail -f /var/log/nginx/access.log

 

Running a Container

Managing images/containers

docker images

View all images on your system

docker ps [-a]

View running or all containers

docker rm [tag/hash]

Delete a container

docker rmi [hash]

Delete an image

Multi-container apps

PHP​

MySQL

Nginx

Redis

Containers can be linked together by Docker daemon

Multi-container apps

MySQL

docker run --name db --expose 3306 -d mysql

Redis

docker run --name redis --expose 6379 -d redis

PHP

docker run --name php --expose 9000 -d 
​--link redis:redis --link db:db php

Nginx

docker run --name nginx  -p 81:80 -d --link php:php -v ./src:/var/www nginx

Docker Compose

  • Define containers in a single file
  • Spin them up with one command
  • Shut them down with one command

A tool for defining and running multi-container applications with Docker

docker-compose.yml

version: '2'
services:
    php-fpm:
        image: php-fpm
        expose:
            - "9000"
        links:
            - redis
            - mysql
    nginx:
        image: nginx
        ports:
            - "81:80"
        links:
            - php-fpm
    mysql:
        image: mysql
        expose:
            - “3306”
    redis:
        image: redis



docker-compose up [-d]
  • Download any images
  • Build images if needed
  • Launch containers in order
  • Link containers together

Managing images

docker-compose ps

View current containers for project

docker-compose stop [app]

Stop any or all running containers

docker-compose rm [app]

Delete a container

docker-compose build [app]

Force a re-build of an image

DEMO

Docker Workflow

Docker Ideologies

  • Single process per image
  • Keep images lightweight
    • ​Use small base images
    • Install minimum packages
    • Combine commands
  • Configuration via environment variables
  • Trash & rebuild
  • Treat containers as ephemeral entities
  • Don't connect to containers directly
  • Store data in volumes

 

Questions ?

Thank you

&

Use Docker

Email - majua@mindfiresolutions.com
Twitter - @majuansari

Github - majuansari

Docker presentation

By Maju Ansari

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