Docker Training

This training aims to give the basic knowlege on Docker core components.

containers management
image management
image optimisation
how to manage an applicative stack
use of docker-compose to simplify docker dore basic use

Docker on Linux install (VM on windows)

Requierements

Windows 10 - 7
Virtualbox
Git bash
vagrant
Download vagrant windows

Clone repository (with gitbash)

cd /C/dev

git clone https://github.com/geoffroyvergne/docker-training.git

Run vm (in folder with Vagrantfile with gitbash)

cd docker-training

vagrant up

SSH

vagrant ssh

Proxy

sudo mkdir /etc/systemd/system/docker.service.d

sudo vi /etc/systemd/system/docker.service.d/http-proxy.conf

[Service]
Environment="HTTP_PROXY=http://fr-proxy.groupinfra.com:3128"
Environment="HTTPS_PROXY=https://fr-proxy.groupinfra.com:3128"
Environment="NO_PROXY=localhost,127.0.0.1,localaddress,.localdomain.com"

sudo systemctl daemon-reload

sudo systemctl restart docker

Share with os host

ls /vagrant_data

Stop

vagrant halt

Clear environment

vagrant destroy -f

Docker Basic commands

PreLoad images

docker pull nginx:1.15-alpine

docker pull postgres:11.1

docker pull adoptopenjdk/openjdk11:alpine-jre

docker pull ubuntu

Get current version

docker --version

Docker version 18.09.3, build 774a1f4

Launch your first container

docker run hello-world

docker : Unable to find image 'hello-world:latest' locally
...

latest:
Pulling from library/hello-world
ca4f61b1923c:
Pulling fs layer
ca4f61b1923c:
Download complete
ca4f61b1923c:
Pull complete
Digest: sha256:97ce6fa4b6cdc0790cda65fe7290b74cfebd9fa0c9b8c38e979330d547d22ce1
Status: Downloaded newer image for hello-world:latest

Hello from Docker!
This message shows that your installation appears to be working correctly.

List images

docker images

docker images -a

Delete image

docker rmi <image>

List all containers (running and not running)

docker container ls --all

docker ps -a

Explore application

docker run --interactive --tty ubuntu bash

docker run -it ubuntu bash

Nginx case

Run container

docker run --rm --name nginx -p 80:80 -d nginx:1.15-alpine

--rm : container auto delete on stop
--name : give a name to the instance
-d : run in background
-p : containerport:hostport
nginx:1.15-alpine image to use

Unable to find image 'nginx:1.15-alpine' locally
1.15-alpine: Pulling from library/nginx
e7c96db7181b: Pull complete 
264026bbe255: Pull complete 
a71634c55d29: Pull complete 
5595887beb81: Pull complete 
Digest: sha256:57a226fb6ab6823027c0704a9346a890ffb0cacde06bc19bbc234c8720673555
Status: Downloaded newer image for nginx:1.15-alpine

Nginx image détails

Access application

curl -v localhost

curl -v 192.168.33.10

Find process

docker ps

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                    NAMES
a871585512ce        nginx:1.15-alpine   "nginx -g 'daemon of…"   4 seconds ago       Up 1 second         0.0.0.0:80->80/tcp       nginx

Linux process

As you can see, docker containers are seen as process for host

pstree
systemd─┬─VBoxService───7*[{VBoxService}]
        ├─accounts-daemon───2*[{accounts-daemon}]
        ├─agetty
        ├─atd
        ├─cron
        ├─dbus-daemon
        ├─dockerd─┬─docker-containe─┬─docker-containe─┬─postgres───16*[postgres]
        │         │                 │                 └─9*[{docker-containe}]
        │         │                 ├─docker-containe─┬─java───28*[{java}]
        │         │                 │                 └─9*[{docker-containe}]
        │         │                 ├─docker-containe─┬─sh───nginx───nginx
        │         │                 │                 └─9*[{docker-containe}]
        │         │                 └─10*[{docker-containe}]
        │         ├─3*[docker-proxy───5*[{docker-proxy}]]
        │         └─10*[{dockerd}]
        ├─2*[iscsid]
        ├─lvmetad
        ├─lxcfs───10*[{lxcfs}]
        ├─networkd-dispat───{networkd-dispat}
        ├─polkitd───2*[{polkitd}]
        ├─rsyslogd───3*[{rsyslogd}]
        ├─snapd───7*[{snapd}]
        ├─sshd───sshd───sshd───bash───pstree
        ├─systemd───(sd-pam)
        ├─systemd-journal
        ├─systemd-logind
        ├─systemd-network
        ├─systemd-resolve
        └─systemd-udevd

Check logs

docker logs -f nginx

Explore container

docker exec -ti nginx sh

Stop container

docker stop nginx

Hello NGINX

cd /vagrant_data/docker-training/demo/hello-nginx/

docker build -t hello-nginx .

docker run --rm --name hello-nginx -p 80:80 -d hello-nginx

curl -v localhost

curl -v 192.168.33.10

docker stop hello-nginx

Tag

docker tag <source> <target>:<version>

docker tag hello-nginx hello-nginx:1.0

Push

docker login

docker tag <login>/<image>:<version>

docker tag <login>/hello-nginx:1.0

docker push <login>/<image>:<version>

docker push <login>/hello-nginx:1.0

Demo App

The demo application is a simple CRUD Todo list. It is stacked in 3 layers :

Frontend (Angular Nginx as reverse proxy)
Backend (Spring Boot)
Database (Postgresql)

1: postgres <- 2: demo-back <- 3: demo-front

Explore image

docker image inspect hello-nginx

Dive

Dive allows you to explore image layers. It gives statistics on image space usage and possible optimizations.

wget https://github.com/wagoodman/dive/releases/download/v0.7.2/dive_0.7.2_linux_amd64.deb
sudo apt install ./dive_0.7.2_linux_amd64.deb

dive gvergne/demo-front:1.0

dive gvergne/demo-back:1.0

Test image quality

CI=true dive demo-back

Fetching image... (this can take a while with large images)
Parsing image...
Analyzing image...
  efficiency: 99.4226 %
  wastedBytes: 4568501 bytes (4.6 MB)
  userWastedPercent: 0.9635 %
Run CI Validations...
  Using default CI config
  PASS: highestUserWastedPercent
  SKIP: highestWastedBytes: rule disabled
  PASS: lowestEfficiency
Result:PASS [Total:3] [Passed:2] [Failed:0] [Warn:0] [Skipped:1]

Images optimisation

Java example

Be careful when you choose images, size can change and be optimized for the same service.

FROM adoptopenjdk/openjdk11 421 MB
FROM adoptopenjdk/openjdk11:alpine 323 MB
FROM adoptopenjdk/openjdk11:alpine-jre 126 MB

Usefull commands

Kill all running containers

docker kill $(docker ps -q)

Delete al containers

docker rm $(docker ps -qa)

Delete all stopped containers (including data-only containers)

docker rm $(docker ps -q)

docker rm $(docker ps -q -f status=exited)

Delete all 'untagged/dangling' () images

docker rmi $(docker images -q -f dangling=true)

Delete ALL images

docker rmi $(docker images -q)

geoffroyvergne / docker-training Goto Github PK

docker-training's Introduction