Docker

docker

https://labs.play-with-docker.com/


docker container run --name c1 -ti alpine sh


docker ps
docker ps --all
docker container ls -a

docker image ls 

docker container inspect c1

docker container rm c1



Creating new image

docker container run -ti ubuntu bash
apt-get update
apt-get install -y figlet
figlet "hello docker"

docker ps -a

docker container commit CONTAINER_ID
docker container diff <container ID>

That’s it - you have created your first image! Once it has been commited, we can see the newly created image in the list of available images.
docker image ls

docker image tag <IMAGE_ID> ourfiglet
docker image ls

docker container run ourfiglet figlet "Konica Minolta"

Dockerfile

index.js
var os = require("os");
var hostname = os.hostname();
console.log("hello from " + hostname);


FROM alpine
RUN apk update && apk add nodejs
COPY . /app
WORKDIR /app
CMD ["node","index.js"]

docker image build -t hello:v0.1 .

docker container run hello:v0.1
 
History

docker images 
docker image history <image ID>

echo "console.log('this is v0.2');" >> index.js
docker image build -t hello:v0.2 .
docker container run hello:v0.2



FROM alpine
VOLUME ["/data"]
ENTRYPOINT ["/bin/sh"]


docker image build -t img1 .

docker images

docker container run --name c2 -ti img1

docker container stop c2 && docker container rm c2


Defining a volume and port

docker container run --name www -d -p 8080:80 -v $(pwd)/html:/usr/share/nginx/html nginx

ls /var/lib/docker/volumes/html/_data

docker container stop www && docker container rm www

docker container run --name www -d -p 8080:80 -v $(pwd)/html:/usr/share/nginx/html nginx

docker-compose

mkdir composetest
cd composetest

docker-compose -v

app.py

import time

import redis
from flask import Flask


app = Flask(__name__)
cache = redis.Redis(host='redis', port=6379)


def get_hit_count():
    retries = 5
    while True:
        try:
            return cache.incr('hits')
        except redis.exceptions.ConnectionError as exc:
            if retries == 0:
                raise exc
            retries -= 1
            time.sleep(0.5)


@app.route('/')
def hello():
    count = get_hit_count()
    return 'Hello World! I have been seen {} times.\n'.format(count)

if __name__ == "__main__":
    app.run(host="0.0.0.0", debug=True)

requirements.txt 
flask
redis

Dockerfile

FROM python:3.4-alpine
ADD . /code
WORKDIR /code
RUN pip install -r requirements.txt
CMD ["python", "app.py"]


docker-compose.yml 
version: '3'
services:
  web:
    build: .
    ports:
     - "5000:5000"
  redis:
    image: "redis:alpine"

docker-compose build

docker images

docker-compose up

docker-compose ps


docker-compose up -d


docker-compose tail -f
docker-compose tail -f web
docker-compose tail -f redis 

mkdir my_wordpress
cd my_wordpress/

docker-compose.yml
version: '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
volumes:
    db_data:


docker-compose up -d

docker-compose exec wordpress  apt-get update 
docker-compose exec wordpress  apt-get install iputils-ping mysql-client
docker-compose exec wordpress bash

linux basic

sytemctl - https://wiki.archlinux.org/index.php/Systemd_(Portugu%C3%AAs)

Systemd é um sistema e gerenciador de serviços para Linux, compatível com os scripts de inicializações SysV e LS. Systemd fornece recursos de paralelização agressivos, usa socket e ativação D-Bus para iniciar serviços, oferece o início de daemons on-demand, 

systemctl list-units
systemctl --failed
systemctl list-unit-files

systemctl status
systemctl is-enabled 
systemctl enable 
systemctl disable unit

systemctl start unit
systemctl stop unit
systemctl restart unit
systemctl reload unit



journalctl -f

journalctl -u unit


lxc list
lxc exec first -- /bin/bash
lxc file pull first/etc/hosts .
lxc file push hosts first/tmp/
lxc stop first
lxc start first

SLide linux basic
- vim
- network
- filesystem
 - etc 
 - usr
 - tmp
 - opt
 - bin
 - sbin

- find
- man
- pwd
- ls
- ps
- dir
- mkdir
- rm
- echo
- touch
-