Docker 101 for Developers
A comprehensive guide for managing containers
PUG Torino - 22th February 2018
$: WHOAMI
uid=7(prometherion) gid=42(kiratech),groups=20(devops),12(developer),61(FATHERINHA),79(headbangingmusic),80(FORMULA1),81(kickboxing),98(bbq),702(cuisine),701(PIZZA)
PUG Torino - 22th February 2018
WHAT IS DOCKER?
Docker is a containerization tool used for spinning up isolated, reproducible application environments.
WHY CONTAINER?
Lightweight
uses the underlying host computer kernel
Distribution
easily distribute and recreate your entire development environment
Build once, run anywhere
no more ( ) environment-specific bugs
DOCKER !== CONTAINERS
Docker, inc.
Docker is a company that provides software (also called Docker) that allows you to build, run and manage software containers
COREOS
[troll_mode_on]CoreOS is dead, long live CoreOS![troll_mode_off]
Light weight and secure alternative to Docker
LXC/LXD
Low-level Linux container runtime
CRI-O
Implements OCI (Open Container Initiative) and based on runc or Clear Containers runtimes
more details on wat?! containers are?
-
Gianluca Arbezzano (@gianarb)
Docker: The fundamentals - Giulio De Donato (@liuggio)
Isoliamo un Processo senza Container
GETTING STARTED
$: DOCKER RUN HELLO-WORLD
image
Made of a set of layers,
like a Class.
CONTAINER
A process based on an Image,
like an Instance.
namespace PhpUserGroup\Turin;
use Docker\Contracts;
use PhpUserGroup\MeetUp;
class DockerMeetUp extends MeetUp
{
public static function build(): IImage;
}
use \PhpUserGroup\Turin\DockerMeetUp;
$meetUp = new DockerMeetUp();
$anotherMeetUp = new DockerMeetUp();
$soOnMeetUp = new DockerMeetUp();
HOW BUILD imageS?
Using Dockerfile: `docker build . - t <USERNAME>/<APP>:<VERSION>`
FROM prometherion/php7-nginx:1.1.3
#
# Installing PHP needed extensions
#
USER root
RUN apt-get update && apt-get install -y \
sqlite3 \
libsqlite3-dev \
&& docker-php-ext-install \
bcmath \
pdo_mysql \
pdo_sqlite \
&& pecl install -o -f redis \
&& rm -rf /tmp/pear \
&& cat > /usr/local/etc/php/conf.d/redis.ini < EOF
extension=redis.so \
EOF \
&& composer global require hirak/prestissimo
#
# Application deployment
#
COPY . ./
OK, BUT...
WHAT THE HECK ARE LAYERS?!
- FROM
- ARG
- FROM
- RUN
- CMD
- LABEL
- EXPOSE
- ENV
- ADD
- COPY
- ENTRYPOINT
- VOLUME
- USER
- WORKDIR
- ARG
- ONBUILD
- STOPSIGNAL
- HEALTHCHECK
- SHELL
HOW START A CONTAINER?
docker run prometherion/php7-nginx:1.1.3
HOW list All CONTAINERs?
docker container ps
HOW VIEW LOGS?
docker logs <CONTAINER_ID|CONTAINER_NAME>
HOW DETACH A CONTAINER?
docker run -d prometherion/php7-nginx:1.1.3
HOW PUBLISH A PORT?
docker run -d -p 8080:8080 prometherion/php7-nginx:1.1.3
HOW MOUNT MY FILES?
docker run \
-d -p 8080:8080 -v `pwd`:/var/www \
prometherion/php7-nginx:1.1.3
HOW USE ENVIRONMENT VARS?
docker run -e FOO=BAR prometherion/php7-nginx:1.1.3
HOW STOP A container?
docker container stop <CONTAINER_ID|CONTAINER_NAME>
HOW REMOVE A CONTAINER?
docker container rm <CONTAINER_ID|CONTAINER_NAME>
SO... are we ready for production?
DOCKER COMPOSE
tool for defining and running multi-container Docker applications.
AVAILABLE COMMANDS
- up
- down
- build
- run
- logs
- scale
- push
DEMO TIME!
Questions...?
Docker 101 for Developers
By Dario Tranchitella
Docker 101 for Developers
Incontro PUG Torino: 22 Febbraio 2018
