Docker container fails to start - "File does not exist: app.py"

[rmahroua]

The Docker container fails to start with the error:

Error: Invalid value: File does not exist: app.py

This is caused by the Dockerfile having a path mismatch issue:

• WORKDIR /app sets the working directory to /app
• COPY copies the entire repository, creating the /app/demobuilder/ subdirectory
• CMD ["streamlit", "run", "app.py", ...] tries to run app.py from /app

But app.py is actually located at /app/demobuilder/app.py
The fix consists in updating the Dockerfile CMD to use the correct path:

# Run the application - Fixed path to app.py in demobuilder subdirectory
CMD streamlit run demobuilder/app.py \
    --server.port=8501 \
    --server.address=0.0.0.0 \
    --server.headless=true \
    --server.enableCORS=false \
    --server.enableXsrfProtection=false

Steps to Reproduce

1. Build the Docker image: docker build -t demobuilder:latest -f demobuilder/Dockerfile .
2. Run the container: docker run -d --name demobuilder -p 8501:8501 demobuilder:latest

This issue affects Docker deployments but not OpenShift S2I deployments. The S2I process handles the file structure differently. The fix has been implemented and tested locally.