Docker - Setup a Python development environment
Docker really is a good tools for Dev-ops , learning and R&D .
Want to try and learning Docker but alway drag until now.
After get back my new iMac need to re-setup all my development environment but I don't want too install too many package and module on the iMac system since is difficult to clean and this is not a good practice and this will cause the current MacOS system also.
Node.JS is more simple we can control the project Module inside a folder but Python is more different and many thing need to link with the system.
of course we can use the Python virtual environment but this also will cause the system and storage messy .
I want a Clean and Clear and consistent same system enviroment for my R&D and project so is time's to learn Docker.
Compare with Virtual Machine, Docker is more Light, Fast and easy way.
I try Virtual Machine with Ubuntu 20.04-desktop-amd64 on the latest macOS Catalina their have a-lot a issue when installing and I feel is slow when using the VirtualBox to development code.
Their are two way to using a Docker
1) Mount a local directory as a volume execute a script on local directory without rebuild.
2) Copy the script into the Docker container and rebuild the container image.
First method is more suitable for me since on development alway need to code and run.
Seconds method is more suitable for production.
Method 1 : Mount a local directory as a volume
1. Create a folder call "docker_dev"
2. Create a Dockerfile with below configuration
FROM python:3.8.5-slim
WORKDIR /usr/src/app
RUN python -m pip install \
parse \
requests
FROM python:3.8.5-slim
Download the Python 3.8.5 slim version Images from docker hub
WORKDIR /usr/src/app
Set a working directory inside docker container
RUN python -m pip install \
parse \
requests
Install python module we need.
3.Build the image by Dockerfile
docker build -t python_env .
-t is give a tag name call python_env
. don't miss the dot is mean the current location
4.Create a source directory
create a folder calling app
5.Create a Python Scripts
create a python script call dev.py with the code
import requests
x = requests.get('https://www.python.org')
print(x.status_code)
6 Confirm that parse module has been installed in the container
docker run -it --rm python_env
>>> import parse
>>> parse.__version__
you will see version like '1.16.0' return on the terminal.
7.Running Python Script Using Docker with Mount a local directory
Execute below command
docker run --rm -v /Users/YourWorkSpace/docker_dev/:/usr/src/app python_env python app/dev.py
--rm option will clean up your container after use.
/Users/YourWorkSpace/docker_dev/
is the local directory
/usr/src/app is the docker container directory
python app/dev.py execute the python script
Run the command on terminal you should see status code 200 return if work.
Method 2 : Build everything inside Docker container image
1. Create a folder call "docker_dev"
2. Create a Dockerfile with below configuration
FROM python:3.8.5-slim
WORKDIR /usr/src/app
RUN python -m pip install \
parse \
requests
COPY app/dev.py .
CMD ["python", "dev.py"]
COPY app/dev.py .
Copy the dev.py to that working directory inside the container
CMD ["python", "dev.py"]
Download the Python 3.7.5 slim version Images from docker hub
3.Build the image by Dockerfile
docker build -t python_env .
*3.Running the Docker Images *
docker run --rm python_env
You should see status code 200 return on terminal when success.
Docker command
docker images
Check all Docker images
docker images -a
Check all Docker images
-a flag will show all images including intermediate image layers
docker build -t ImageName .
Docker Build Images container
docker run --rm ImageName
Run DockerImages container
docker run -it --rm ImageName
Run Docker Images container with commands
docker rmi ImageName
Delete a docker images
docker system prune
Purging All Unused or Dangling Images, Containers, Volumes, and Networks
docker system prune -a
To additionally remove any stopped containers and all unused images (not just dangling images), add the -a flag to the command: (Delete everything)
docker ps -a
Show both running and stopped containers
refer:
https://realpython.com/python-versions-docker/
https://www.digitalocean.com/community/tutorials/how-to-remove-docker-images-containers-and-volumes
https://docs.docker.com/engine/reference/commandline/container_ls/