Build Architecture#
OS Image Inheritance#
The ngen runtime environment (RTE) OS image is built from the following inheritance:
ngen-forcing/Dockerfile.bmi-forcings: Base image with packages NextGen_Forcings_Engine_BMI and ewts
↓
ngen/Dockerfile: ngen, partitionGenerator, and various extern submodule packages
↓
nwm-rte/Dockerfile.rte: RTE component packages
See the Build Flow diagram.
Tested Platforms and Python Versions#
The build has been tested with Rocky Linux 8 and Debian 12 (Bookworm), and with ngen base images using Python 3.11 and Python 3.12. The current default image lineage uses Debian 12 and Python 3.12.
nwm_eval is installed in a separate Python 3.11 virtual environment because its pinned dependencies are not compatible with Python 3.12.
Dockerfile.rte has also been tested with Podman in an unmerged branch. The resulting image built and ran the RTE pytest realization successfully. Podman is not exercised by the repository's CI workflow.
RTE Component Packages#
The RTE component Python packages include:
| Code Repository (each includes 1 or more packages) |
Python Virtual Environment |
|---|---|
nwm-fcst-mgr |
ngen-python (default) |
nwm-msw-mgr |
ngen-python (default) |
nwm-cal-mgr |
ngen-python (default) |
nwm-region-mgr |
ngen-python (default) |
nwm-data-assimilation |
ngen-python (default) |
nwm-eval-mgr |
eval_verf |
The nwm-cal-mgr package must be installed even when calibration workflows are not used because RTE modules import calib.strategy during normal startup.
External Access and Runtime#
Typical builds access GitHub and GHCR. Data setup also requires S3 and the EDFS streamflow-observations API. Building a realization requires the EDFS hydrofabric API unless existing local hydrofabric data is provided.
Image Provenance#
The image records OCI provenance labels and source metadata JSON files. Base-image records are inherited under /ngen-app/; RTE-installed package records are written under /ngen-app/git-info/. See Caveats for behavior of alternative build options that involve "reinstalling" Python packages from nwm-ewts and ngen-forcing (for developing and testing).