#GCP - Storage/Datastore/PubSub image resizing app demo
This is an introductory demo that shows how to leverage GCP services and cloud best practices (decoupling, high availability, Disaster Recovery, Scalability) to create a web application.
This demo has a SOA design, using PHP for the frontend and Python in the backend. The demo web app allows users to fill out a short form with Name, Email, and Picture. The picture is resized, and another page shows the resized picture of all users. The idea is to simulate a social media app, but the concepts can be applied to other examples.
The app has 3 main services:
Front End: hosting the main page, and ingesting the form from users Back End: transforming the picture into thumbnail size Render: displaying all users' thumbnail pictures
Intended app setup, logic, and flow:
-
Global Load Balancer
- 3 backends
- frontend
- render
- bucket with thumbnail pictures (CDN enabled)
- 3 backends
-
Multi Regional GCS bucket
-
Front End
- 1 or more Instance Groups (in different regions)
- PHP + GCP APIs (Storage and PubSub)
- Allows users to upload picture
- Upload picture into a temp folder in GCS bucket
- Sends a message to a PubSub topic
- message content: GCS object location, name, email
-
Back End:
- 1 or more Instance Groups (in different regions)
- Python + GCP APIs (Storage, PubSub, Datastore)
- Subscribe to the PubSub topic, reads the message
- download temp picture, resizes, uploads to GCS bucket
- create an entry in Datastore:
- email (as the index); name; thumbnail url; data uploaded (important for rendering later)
- if everything suceeds .... acknoledge the message (removing from the PubSub topic, to avoid message to be processed again)
-
Render:
- 1 or more Instance Groups (in different regions)
- PHP + GCP API (Datastore)
- Queries Data store, sort entities by the newest (so we can display the newest picture 1st)
- creates an array in PHP, loop, and display
Highlights/Teachble points:
- GCP Global Networking, LB is Global, one single IP (High Availability)
- Due to global networking, we can have VMs running our services in multiple regions (High Availability / DR / Scalability)
- PubSub (Decoupling)
- Datastore (Decoupling / Scalability)
- Storage (High Availability / DR)
- GCE with Autoscaling, Templates (Scalability / Repeatable)
NOTE: I am not and do not claim to be a web developer, or a developer at all. The demo serves its purpose of proving a few points. Feedback is more than welcome, but do it in a nicer and non-derrogatory way. I'd love to incorporate feedback and have a more robust and elegant looking app.