Set _RELEASE with docker build env ?

[victorjourne]

https://github.com/IA-Generative/Streamlit-dsfr/blob/cb2cdf72c7ba1902c81b2c92bd074243d927a464/Dockerfile#L148

[matiboux]

See the __init__.py for more context: https://github.com/IA-Generative/Streamlit-dsfr/blob/cb2cdf72c7ba1902c81b2c92bd074243d927a464/app/app/streamlit_dsfr/__init__.py#L22-L43

The behavior depends on the environment:

• In dev, Streamlit takes a URL to load custom components from a hot reloading NodeJS web application.
• In prod, Streamlit takes a path to load custom components from the statically compiled HTML files.

The _RELEASE flag value is constant but defined at initialization (at run time), so we cannot rely on a dynamic environment variable.

Another strategy would have been to use init different source code for each environment. However, using the release flag is the recommended strategy in Streamlit project templates and avoids code duplication.