Docker web app fails to start: FileExistsError for /PrimeDesign/reports

[francescopatane96]

Description

The PrimeDesign Docker web app fails during startup with a FileExistsError for /PrimeDesign/reports, causing Gunicorn to shut down.

Steps to reproduce

Run the documented command:

docker run -p 9994:9994 pinellolab/primedesign:latest primedesign_webapp

Expected behavior

The web app starts successfully and is accessible at http://localhost:9994.

Actual behavior

Gunicorn starts four workers, but one fails while creating the reports directory:

File "/PrimeDesign/web_app/app.py", line 36, in <module>
    os.makedirs(UPLOAD_DIRECTORY)
FileExistsError: [Errno 17] File exists: '/PrimeDesign/reports'

[INFO] Shutting down: Master
[INFO] Reason: Worker failed to boot.

Likely cause

The directory existence check and creation are separate operations:

if not os.path.exists(UPLOAD_DIRECTORY):
    os.makedirs(UPLOAD_DIRECTORY)

Multiple workers can pass the check before any worker creates the directory. A subsequent creation attempt then raises FileExistsError. This makes the failure timing-dependent.

Suggested fix

Replace the check-then-create sequence with:

os.makedirs(UPLOAD_DIRECTORY, exist_ok=True)

This tolerates concurrent directory creation while preserving existing contents. The proposed fix has not yet been tested.

Environment

• Host: macOS
• Docker image: pinellolab/primedesign:latest
• Gunicorn: 20.1.0
• Python inside the container: 3.8