Aaron VanSledright

Tag: flask

  • Building out a reusable Terraform framework for Flask Applications

    I find myself utilizing the same architecture for deploying demo applications on the great Python library Flask. I’ve been using the same Terraform files over and over again to build out the infrastructure.

    Last weekend I decided it was time to build a reusable framework for deploying these applications. So, I began building out the repository. The purpose of this repository is to give myself a jumping off point to quickly deploy applications for demonstrations or live environments.

    Let’s take a look at the features:

    • Customizable Environments within Terraform for managing the infrastructure across your development and production environments
    • Modules for:
      • Application Load Balancer
      • Elastic Container registry
      • Elastic Container Service
      • VPC & Networking components
    • Dockerfile and Docker Compose file for launching and building the application
    • Demo code for the Flask application
    • Automated build and deploy for the container upon code changes

    This module is built for any developer who wants to get started quickly and deploy applications fast. Using this framework will allow you to speed up your development time by being able to focus solely on the application rather than the infrastructure.

    Upcoming features:

    • CI/CD features using either GitHub Actions or Amazon Web Services like CodePipeline and Codebuild
    • Custom Domain Name support for your application

    If there are other features you would like to see me add shoot me a message anytime!

    Check out the repository here:
    https://github.com/avansledright/terraform-flask-module

  • Where Is It Five O’Clock Pt: 1

    I bought the domain whereisitfiveoclock.net a while back and have been sitting on it for quite some time. I had an idea to make a web application that would tell you where it is five o’clock. Yes, this is a drinking website.

    I saw this project as a way to learn more Python skills, as well as some more AWS skills, and boy, has it put me to the test. So I’m going to write this series of posts as a way to document my progress in building this application.

    Part One: Building The Application

    I know that I want to use Python because it is my language of choice. I then researched what libraries I could use to build the frontend with. I came across Flask as an option and decided to run with that. The next step I had to do was actually find out where it was 5PM.

    In my head, I came up with the process that if I could first get a list of all the timezone and identify the current time in them I could filter out which timezones it was 5PM. Once establishing where it was 5PM, I can then get that information to Flask and figure out a way to display it.

    Here is the function for identifying the current time in all timezones and then storing each key pair of {Timezone : Current_Time }

    def getTime():
    now_utc = datetime.now(timezone('UTC'))
    #print('UTC:', now_utc)
    timezones = pytz.all_timezones
    #get all current times and store them into a list
    tz_array = []
    for tz in timezones:
        current_time = now_utc.astimezone(timezone(tz))
        values = {tz: current_time.hour}
        tz_array.append(values)
        
    return tz_array

    Once everything was stored into tz_array I took that info and passed it through the following function to identify it was 5PM. I have another function that identifies everything that is NOT 5PM.

    def find5PM():
    its5pm = []
    for tz in tz_array:
        timezones = tz.items()
        for timezone, hour in timezones:
            if hour >= 17:
                its5pm.append(timezone)
    return its5pm

    I made a new list and stored just the timezone name into that list and return it.

    Once I had all these together I passed them through as variables to Flask. This is where I first started to struggle. In my original revisions of the functions, I was only returning one of the values rather than returning ALL of the values. This resulted in hours of struggling to identify the cause of the problem. Eventually, I had to start over and completely re-work the code until I ended up with what you see above.

    The code was finally functional and I was ready to deploy it to Amazon Web Services for public access. I will discuss my design and deployment in Part Two.

    http://whereisitfiveoclock.net