A Recipe Search Engine and Aggregator Called Recipe Finder

• #flask
• #python
• #bootstrap
• #heroku
• #jquery
• #sendgrid
• #sqlite

Bruno Oliveira

https://hidden-reaches-53473.herokuapp.com/

What’s your background and what site are you running in production?

Hello, my name is Bruno Oliveira. I’m currently working as a web developer with Java, as I have for the past 3 and a half years which is almost my whole professional career.

I studied Civil Engineering before switching to Computer Science, and since then I never looked back. I attended algorithm competitions during university where I improved my skills a lot, and since graduation I’ve worked in Portugal, Lisbon (where I grew up), Antwerp in Belgium working on healthcare focused web applications and now in Amsterdam, where I work at Software Improvement Group – a company focused on software quality and its assurance.

I started working on a recipe search engine and aggregator called Recipe Finder in October 2019. I am the sole developer of the whole project including handling the deployment to Heroku. I plan to keep on developing it over the next few months.

From the business side of things, let’s say I am a foodie, so working on a recipe search and aggregator was something I’d be keen to work on, so it’s easy to keep myself motivated!

My main motivation to start this project was to learn more about Python for web development, and I chose Flask since it’s a framework I had heard about a while back, and it seemed to have the right amount of functionality built-in to allow me to get up to speed quickly.

What motivated you to use Flask / Python?

On my daily job, I use Java and its eco-system so I know it quite well.

From my experience, it always introduces large configuration overhead, and I was not aware at the time of any way to deploy a Java web application on Heroku. I was aware of NodeJS’ possibilities for deployment, but I wanted to use a different language for the back-end as a learning experience. Since I had used Python in the past, it was a natural choice.

I chose Flask for my app (as opposed to other popular frameworks, say Django), because Flask is very un-opinionated, it starts up an embedded server with little to no additional configuration out of the box, so I felt that this was the best way to move forward since I wouldn’t be too tied into any particular constraints that would block me completely.

I also knew that Flask can work well for writing RESTful applications, which is something I wanted to try and do (even if not perfectly from the technical side to begin with).

I think in the future if I’d ever re-write it, I’d still use Flask and Heroku but I’d try to make it even better from an architectural point of view. Such as structuring my endpoints better and organizing the server-side code in a more logical way.

Is your site a monolith or broken up into microservices?

My app uses a combination of a monolithic architecture with what could be seen as microservices, as I leverage an external API service to lend me some functionality.

For example, to get recipes I pull down this information from the external API (more on this later) and then feed it into Jinja which is Flask’s default template language. This is done server side.

I also have the database classes and models saved on the server for things like Ingredients, Recipes, Suggestions, etc., and they all live under the same file in the same project, so it’s monolithic in that regard.

So far the experience has been good with the current architecture and since it’s a small-sized code base, it’s still possible for me to deliver what I feel is quite a lot of interactivity and functionality in under 300 lines of server code which is very nice in my opinion.

My advice for others is what I said to myself when I started this: no matter what, it will always be a great learning experience. So focus on delivering small increments of functionality, have a clear goal and architecture in mind, and work towards it with what you know.

Don’t let design conventions or best practices, or even other people tell you how you need to do something. I have learned with this project that if you are focused, have a clear vision in mind and the will to learn, you can do anything!

Are you using server rendered templates with sprinkles of JavaScript or is there an API based back-end with a JavaScript heavy front-end?

My web app falls into the first category, I use Jinja, and since my web app is mostly presenting data with little client-side interaction, rendering the templates server-side works quite well for me.

I don’t have real requirements for my app per se, except that I want users to get to the recipes they search for as efficiently as possible. So with server-side rendering it works great.

For example, after a user searches for an ingredient, I call an external API to get the results in JSON format and pass this into the Jinja template. It seems quite intuitive to me, and it has allowed me to extend my app quite easily up until this point.

I think if your web application will be data based in the sense of having to show lots of data to users, going with Flask + Jinja and using server-side rendering is a great way to architecture your application. But remember, adapt and choose what works best for you and the rest will follow.

What does the rest of your tech stack look like?

This is something I found interesting while working on this project all the way from an empty folder to deploying it.

To deploy even such a simple app as the one I am working on, there are a lot of moving pieces:

• There’s Python and Flask for the back-end with extensions like Flask-Login to handle user logins and WTForms for form validation.

• Next up, there’s SQLite as a simple database. It’s easy to use locally, and in production on Heroku it runs in memory which means it does get wiped from time to time which is a downside but for short-lived things such as displaying recent search results and showing ingredients in the UI it’s great. I will be upgrading to PostgreSQL on Heroku soon though.

• On the front-end, I’m using Bootstrap for responsiveness and styling along with JavaScript and jQuery to handle some interactivity and communicating with the back-end.

Which external SAAS tools does your site depend on?

Currently I am using two external services to help power my app in its current state:

• The Spoonacular recipe API to provide me with some recipes. I chose it because I had read about it a while back and always wanted to explore it more in depth.

• For sending transactional emails I use SendGrid mainly because I have used it before, it’s easy to setup, very robust and reliable. It works great overall. Their free usage rates are pretty good too.

Which cloud hosting provider or platform are you using to host everything?

I am using Heroku to host my app because again I am familiar with it and the free tier and solutions they offer overall are really good for these kinds of side projects.

I have the app running on one free dyno with 512mb of RAM using the complete Heroku-18 Stack which is based on Ubuntu 18.04 LTS.

Heroku uses Gunicorn to allow deployed Python apps to run concurrently, so I configured that as well. Gunicorn forks multiple system processes within each dyno to allow a Python app to support multiple concurrent requests without requiring them to be thread-safe.

In Gunicorn terminology, these are referred to as worker processes (not to be confused with Heroku worker processes, which run in their own dynos).

I am not paying anything per month due to low traffic and using the free tier of Heroku.

What does your deployment process look like?

To deploy, I decided to go real simple and I enabled Heroku to allow two things:

1. Integration with my private GitHub repository
2. Allow for automatic deploys

Both of these things can be setup on Heroku’s dashboard and for my current situation they work quite well. That’s because I know exactly which code ends up in production and how it gets there. It’s simply the master branch of my GitHub repository.

To initiate a deploy, thanks to GitHub’s integration with Heroku I can push code to master, then Heroku will trigger a re-build, and my app will be live within minutes of my push. The code goes straight from my dev box into production, which is nice for this kind of side project.

There’s only a tiny bit of down time for the Heroku dyno to restart but that’s only because I’m on the free tier with 1 dyno. If I had multiple dynos then there could be zero down time.

I like how this works for me. I use localhost to perform most of the testing and debugging which I can do fully thanks to using SQLite as my database. When I am confident things are fine tuned I push it to GitHub and then it ends up live on my site shortly after.

How have you planned for disasters, unexpected events or malicious users?

Not a lot has been done on this front since I am not expecting a lot of traffic at the moment.

Future plans will most likely include to do standard stuff like sanitizing user input, provide good user feedback, and avoid disasters by using as much security around my endpoints as possible.

All the while handling things nicely when we fall off the happy path. All of this has been a learning experience and a work in progress for me.

What’s your advice for others who are running similar stacks in production?

My main advice is to definitely use GitHub or any other source control versioning system / platform.

Also, it should go without saying but people can really mess the basics up. Use automatic deploys if using Heroku since they allow you to move very fast!

Regarding Flask and Python specifically, I recommend going to RealPython and of course the official Python and Flask docs as needed. These have helped me a lot.

Where can we go to learn more?

My GitHub is a good place to start. If you want to ask me a question drop me a line at olivbruno8@gmail.com. Also I’m happy to discuss anything tech related with you.

– Bruno Oliveira, Software Developer

Nov 20, 2019