Docker

Introduction

Environments are not the same. For example you develop on a Macbook and server is Ubuntu server. Docker runs on containers. Docker file builds a docker image, which contains all project code,installments of needed programs, complete application wrapped in an image, which is designed to sit on top of a container.

Video Source

Solid written tutorial

Tutorial

Create file called Dockerfile

Take a look at workspace/tutorial project.

  • FROM will take from the Python image for DockerHub.
  • COPY current directory
  • RUN python specific stuff in requirements.txt
  • CMD Commands to run, first the python command and then any python files
FROM python:3-onbuild
COPY . /usr/src/app
RUN pip install -r requirements.txt
CMD ["python", "api.py"]

You can run services like:

docker run

These usually has several arguments like port numbers, which can become tedious that is why it is better to use a docker-compose.yml file, like below. docker-compose is a yaml file and spins up all the containers we need.

version: '3'

services:
	# you name the services
    product-service:
    	# Directory where the dockerfile is
        build: ./product
        # sourcedirectory:/directoryonhost
        volumes:
            - ./product:/usr/src/app
        # localhostport:containerport
        ports:
            - 5001:80

    website:
    	# gets from dockerhub
        image: php:apache
        volumes:
            - ./website:/var/www/html
        ports:
            - 5000:80
        depends_on:
            - product-service

Run docker-compose file by running this command docker-compose up. You can stop the services with CTRL + C. The containers can be started up by using docker-compose up -d This will allow you to still navigate in the terminal and you can stop it by docker-compose stop.

Commands

  • docker ps -a : List containers with name, ID, etc
  • docker stop d31a3b925d89 : Stop container with ID
  • docker system prune : Remove stopped containers and dangling images
  • docker images : List images with repository, image ID, etc
  • docker rmi e91727a11cd7 : Remove image with image ID
  • docker build -t webserver-image:v1 . : Build image with name: web server-image version: v1
  • docker run -d -p 5000:80 webserver-image:v1 : Run image in container port 5000 locally and port 80 on container
  • docker-compose up : Build image and run in container based on configuration in docker-compose.yaml file
  • docker-compose up --build : To do a fresh build of images. Needed to update files.
  • docker-compose up -d : Create containers and -d to launch in daemon mood (still navigate cmd)
  • docker-compose stop : Stop all containers

Deploy Static website as container

Medium article](https://medium.com/myriatek/using-docker-to-run-a-simple-nginx-server-75a48d74500b)

dockerfile

FROM nginx:alpine

RUN mkdir /www
COPY dist/index.html /www/index.html
COPY dist/css /www/css
COPY dist/js /www/js
COPY dist/img /www/img
COPY nginx.conf /etc/nginx/nginx.conf

The first line defines our base image. The second line copies the content of the current directory into a particular location inside the container.

nginx.conf

events {}

http {
    server {
        listen 80;

        root /www;
        index index.html;

        location / {
            include  /etc/nginx/mime.types;
            try_files $uri $uri/ /index.html;
        }
    }
}

docker-compose.yaml

version: '3.7'

services:
    web-service:
        build: ./
        ports:
            - 5000:80
      	volumes: ['./server/src:/app'] # To auto-reload new code from server/src to Docker app