Essential Docker for Python Flask Development

Name: Essential Docker for Python Flask Development
Rating: 4.1 (196 reviews)

Learn how to effectively use Docker and Docker Compose to develop production ready applications

Created byJorge Escobar

Last updated 12/2017

English

What you'll learn

You will learn the fundamental concepts for the design of Docker Containers, specifically for Flask web development
You will be introduced to the Dockerfile structure
You will learn how to setup a server cluster using Docker Compose
You will learn how to effectively interact with containers, write tests and debug applications

Course content

5 sections • 21 lectures • 2h 22m total length

Introduction1:03
What do we want to accomplish in this course?
Prerequisites
What do I need to have to complete this course?
Introduction to Docker2:41
What is Docker exactly?
Installing the Docker Client4:54
The Docker Clients
Docker is available for both Windows and Mac Operating Systems as a native client that utilizes both of those OS’s hypervisor capabilities
Install Docker for Mac
Get dmg
Run it
Click the Whale to get preferences
Go to File Sharing and add "/opt"
Check the versions

$ docker --version Docker version 1.12.0, build 8eab29e $ docker-compose --version docker-compose version 1.8.0, build f3628c7 $ docker-machine --version
docker-machine version 0.8.0, build b85aac1
Docker's Hello World5:09
Check the hello-world container docker run hello-world
What did just happen?
Docker tried to check if it had a hello-world "image"
Since it didn't find it, it went to Docker Hub to see if it could find it there
It found it and downloaded the "latest" version
It then created a "container" based on this image
The container ran following the commands on the image's "Dockerfile"
Docker Concepts11:21
Images
Versions (:version)
You build an image from a Dockerfile using docker build
Containers
Running or not running
Use docker ps to see running containers and docker ps -a to see all containers
You start a container using docker run or docker start
You stop a container using docker stop
Foreground vs Background Containers8:02
Foreground vs Background
Foreground: Starts the process in the container and attach the console to the process’s standard input, output, and standard error
Background or detached: Containers started in detached mode exit when the root process used to run the container exits
Example foreground container
Run an Ubuntu server docker run -it ubuntu:16.04 /bin/bash
Here we pass the -i flag which means "Keep STDIN open" i.e., the keystrokes are routed to the container
We also pass the '-t' flag which means "Allocate a pseudo-tty" or terminal
We pass the image with a version
The /bin/bash is an optional command we can pass the container when it starts
Example background container
Run an nginx web server docker run -d -p 80:80 --name webserver nginx
Here we pass a -d flag, which means "detached" or Background
We also pass a '--name' flag, which allows us to reference the container with a name
Go to localhost. "Welcome to nginx" should be up
Check docker ps and you should see the container
Stop the container using docker stop webserver
Section 1 Quiz

A Basic Flask Container11:53
Just using python hello.py
Write the Dockerfile
Build the image with docker build -t hello-app .
Running our Basic Flask Container9:42
Run the container with docker run -d -p 5000:5000 --name hello-server hello-app
Check that the container is running
Go to localhost:5000. You should see Hello, World!
Stop the container using docker stop hello-server
Check that the container is not running with docker ps
Check the container is still available with docker ps -a
You can restart the server using docker start hello-server
You can log in to the server using docker exec -it hello-server bash
Caveat: if you change the code, it's not reflected on the container. We'll fix that next.
A Hot Reload Gunicorn Flask App9:21
Write the Dockerfile
Build the image with docker build -t guni-app .
Run the container with docker run -d -p 80:80 -v /opt/docker-guni-hello:/app --name guni-server guni-app
Note the -v flag. That means now the local directory is "mounted" on the container, and any changes you make are reflected on the server, thanks to the --reload flag.
Section 2 Quiz

Introduction to Docker Compose4:36
What is Docker Compose?

Docker Compose allows you to programmatically spawn multiple containers specifying the relationship between them
The docker-compose.yml
The MySQL Counter App10:04
Here we will build a simple Flask counter application that uses MySQL as its backend.
The docker-compose file8:09
Here we go through the structure of the docker compose file.
Starting our Docker Compose App6:41
Build the image with docker-compose build
Run the container with docker-compose up
Initialize tables with docker exec -it counterapp_web_1 python dbinit.py
Hit / and see the counter incrementing every time you refresh the page
Interacting with the Containers6:31
To use the app container docker exec -it counterapp_web_1 /bin/bash
To use the mysql server do docker exec -it counterapp_db_1 mysql -uroot -prootpass
If you do any changes and need to reset the containers, you can do docker-compose rm -v
Running Tests8:25
Run tests by doing docker exec -it counterapp_web_1 python tests.py
A MongoDB Counter App8:55
Here we will create a similar Flask counter app, but this time using MongoDB as the database and using the factory pattern.
Starting up the App8:27
Build the image with docker-compose build
Run the container with docker-compose up
Hit / and see the counter incrementing every time you refresh the page
To explore the mongodb database, open a new tab and do docker exec -it counterapp_db_2 mongo
Do use counter, show collections, db.counter.find()
Testing the App8:46
To run tests, do docker exec -it counterapp_web_2 python tests.py
Using PDB with the Docker Container5:22
Using PDB with Docker Compose
Start the database as it's own demon service: docker-compose up -d db
Now start the application with pdb enabled: docker-compose run --service-ports web
You will get the live log of just the app and you can stop with CTRL-C
Try adding a pdb on the code
To stop the db docker-compose stop db
Section 3 Quiz

Requirements

A computer with internet access and administrative access to install packages
Good understanding of how to use the command line interface, internet and code editors
Good knowledge of the Flask web framework

Description

This course will teach you the essential knowledge required to integrate Docker in your everyday development flow. Docker is an easy way for developers to recreate a production-level server cluster locally in their desktop or laptop using very few resources.

A lot of companies and startups are moving to Docker, because it speeds up the development process and reduces the amount of debugging that occurs when they create software against different versions of their operating system and libraries.

The course covers the basic concepts and goes through the setup of different use cases, specifically Flask-related, from a simple web application to MySQL and MongoDB multi-server setups.

At the end of the course students will be able to write solid Dockerfiles and Docker Compose configuration files that will allow them to write software against reliable environments and without the need to install packages like Python, MySQL or MongoDB. Just install the simple Docker client for Windows or Mac and you’re set to go!

If you already know the basics of Flask and you are interested in how to setup Docker containers for their development, this is the course for you.

The course is divided in 3 sections:

Introduction which covers all the concepts necessary to understand how Docker works and how to install it
Simple Flask Containers which gently introduces to the basics of containers and how to write a good Dockerfile and how to interact with the containers
Docker Compose which goes into the composing part of Docker, where with one file you can spawn a complete architecture stack, like an application server and a database server running in parallel and synchronized as production environments do

The course has more than 2 hours of video tutorials as well as the source code at the end of each section, so that you can fork and play with the Docker setups.

The course can take anywhere from 1 to 3 days to complete based on how much material the student completes daily.

Additionally we’re constantly updating the course, adding contents thanks to the feedback of our students.

Join this course and continue your path to becoming a professional backend web developer!

Who this course is for:

Programmers and developers with basic Flask knowledge who want to expand their Docker skills
Application architects who want to understand better how to scale their applications
Startup CTOs who want to understand better best practices for application deployment
Computer Science Students who want to get exposed to real life concepts

Essential Docker for Python Flask Development

What you'll learn

Explore related topics

Course content

Introduction6 lectures • 33min

Simple Flask Containers3 lectures • 31min

Docker Compose10 lectures • 1hr 16min

Conclusion1 lecture • 1min

Bonus Section1 lecture • 1min

Requirements

Description

Who this course is for: