Development install mode

Development install mode allows an environment with a baked dpone version to test a newer snapshot package without rebuilding the base image.

This mode is intended for development and review environments, not normal production releases.

Concept

1. CI builds a snapshot package.
2. The runtime sets package overlay environment variables.
3. The process starts through dpone-runtime-exec.
4. The wrapper installs the snapshot into a writable target directory and prepends it to PYTHONPATH.

Production should normally use immutable images and release tags.

Environment variables

Variable	Purpose
DPONE_INSTALL_MODE	baked or snapshot.
DPONE_PACKAGE_SPEC	Package spec such as dpone==X.Y.Z.devN.
DPONE_PACKAGE_INDEX_URL	Package index containing the snapshot.
DPONE_PACKAGE_EXTRA_INDEX_URL	Optional extra index URL.
DPONE_PACKAGE_EXTRA_INDEX_URLS	Optional shell-style list of additional indexes.
DPONE_PACKAGE_TARGET	Writable directory added to PYTHONPATH.
DPONE_PACKAGE_PIP_ARGS	Optional extra pip install flags.

Dry run

DPONE_INSTALL_MODE=snapshot \
DPONE_PACKAGE_SPEC='dpone==X.Y.Z.devN' \
DPONE_PACKAGE_TARGET=/tmp/dpone-overlay \
dpone-runtime-exec --dry-run python -c 'import dpone; print(dpone.__version__)'

Real run

DPONE_INSTALL_MODE=snapshot \
DPONE_PACKAGE_SPEC='dpone==X.Y.Z.devN' \
DPONE_PACKAGE_TARGET=/tmp/dpone-overlay \
dpone-runtime-exec python -m dpone --help

Practical notes

• DPONE_PACKAGE_TARGET must be writable.
• The target directory is recreated on every start to avoid stale files.
• This mode assumes a baseline dpone already exists in the image so dpone-runtime-exec is available.
• Use public PyPI or a private package index according to your environment policy.