Lab: Cloud Storage locally with fake-gcs-server

What you will learn in this TP

• Run fake-gcs-server
• Use the Cloud Storage library
• Test without the cloud

Introduction #

What you will learn in this section

• Run fake-gcs-server
• Use the Cloud Storage library
• Test without the cloud

Context. The report export code must be tested in CI without Google Cloud access. You run it against an emulator.

Prerequisites: Docker, Python 3 and the Google Cloud SDK (gcloud with emulator components); no Google Cloud project or billing needed  ·  Estimated time: 35 min

Export code automatically tested against emulated Cloud Storage.

Hands-on #

Guided steps, with their solution.

1. 1. Start the emulator

   Why? STORAGE_EMULATOR_HOST redirects the Python library to the emulator.

   Run fake-gcs-server and install the library.

2. 2. Write the export code

   Why? Organising by date with prefixes eases lifecycle and search.

   Create export.py that creates the bucket if needed and uploads a CSV under YYYY/MM/ with metadata.

3. 3. Test automatically

   Why? The same test runs in CI with a fake-gcs-server service.

   Write a pytest test that exports then reads the object back, and run it.

Difficulty level : ●●○○○ (2/5)