👋 Welcome to our github repo
This application is currently deployed using Python/Flask/Gunicorn to heroku.
Web Framework: Python/Flask is a lightweight web framework that allows us to build simple applications quickly.
Application Server: Gunicorn - aka Green Unicorn is a lightweight http server which is simple to use and compatible with a wide variety of software. It differs from a web server such as apache or nginx in that Gunicorn is an application server
Hosting and Deployment: Heroku Cloud Plaftorm
Markup/Styling: HTML/CSS
Graphics/Application Logic: Javascript
Clone this repo to wherever you like to keep your files
Ensure you have Python > 3.7 installed correctly on your machine - Guide
Open up your terminal and cd Linux/Mac or chdir Windows to cloned repository folder on your computer
Install Python Virtual Environment "pip" package using python package manager
pip install virtualenv
Create a virtual environment for our project, this will keep all of the packages we use for this project seperate from other projects. We need venv for this reason - if two or more projects need two or more different versions of a package to run it could cause issues for you if you kept all python packages/dependencies in the same folder on your system.
virtualenv dscmqwebsite
Activate your virtual environment, once activated the commands you issue, i.e installing packages will end up in their own special folder made just for this project.
Mac/linux
source dscmqwebsite/bin/activate
Windows users
dscmqwebsite\Scripts\activate
Note
When you are finished working on the project, you can type deactivate to exit the virtual environment
Activate your python venv first so we don't install packages in the system python path or whatever else you have configured
We are using a requirements.txt file, which is a list of packages and version numbers
It was generated using the format freeze flag to remove the /tmp/ stuff and get just the version numbers required for packages pip3 list --format=freeze > requirements.txt dont run this
To install the dependencies required for this project run the following command
pip install -r requirements.txt
cd or chdir to the root folder in the root folder of the project i.e "<path-to-where-you-put-it>/DSCMQWebsite"
We need to set some environment variables for our flask session. We could add them to our terminal configuration later make sure to remember if you open a new terminal you will need to set them again for now
Mac/Linux Users
export FLASK_APP=wsgi.py - tells flask which the file name of our python app, note it will run fine without this command usually as flask will look for a file named app.py or wsgi.py of which we have the latter
export FLASK_ENV=development - runs a development version of the server with debugging enabled
Windows Users
set FLASK_APP=wsgi.py
set FLASK_ENV=development
Run the flask app
flask run
Success 😀 You should now see a prompt in your terminal with an IP address or URL where you can access the DSCMQ Website running locally on your computer
Install Heroku CLI and familiarise youself with it
We will create a heroku application and deploy it, using the "Procfile" located in the root directory of our project. It contains one instruction, "web: gunicorn wsgi:app" - which instructs Heroku to launch a your web app using Gunicorn as the http server
note: set your terminal to the project root directory first
heroku create <name-to-give-app>
check that a remote repository call heroku has been created
git remote -v
Next we will push the master git repository, i.e this project to the heroku remote git repository we just created - it will also do some fancy stuff and deploy the app for us - neat!
git push heroku master
After a while the project will have been built and deployed and you should now see some output on your terminal confirming its success with link to your site.. see below first
Lastly, and importantly, we need to create a 'Dyno' this is like a little virtual computer that runs our website on the heroku platform - otherwise we will see and error when running heroku logs --tail that suggests our web server is not running
heroku ps: scale web=1
Access your newly deployed site quickly
heroku open
I recommend VS Code, in part because you can run code . after you clone the repository in your terminal and then it will launch VS Code and you can finish the rest of the setup of your environment - its a nice workflow
Error: Could not import "wsgi".
- Make sure you are in the root folder in your terminal before running
flask run - Check that your virtual environment is activated and that the dependencies were installed correctly in your virtual environment /bin folder - you can find the folder on your system and check for yourself
When checking heroku logs and see it says something along the lines of a webserver is not running GET / yada yada then run..
heroku ps: scale web=1