Bootstrap README file

README.rst

+Software Heritage virtual environment packaging manifests
+=========================================================
+
+This repository contains the manifests and scripts to automate the packaging of
+SWH applications into (fairly) reproducible Python virtual environments, and
+then onto container images.
+
+Problem statement
+-----------------
+
+To move away from our legacy Debian-based packaging and deployment workflow, we
+are using Python virtual environments to generate (fairly) reproducible
+deployment environments, that would be consistent between:
+
+ - docker-based local environments
+ - "bare VM/Metal" deployments (on Debian systems still managed by puppet)
+ - elastic deployments based on k8s
+ - CI environments used for testing packages
+
+We want the input for generating these environments to be declarative (for
+instance, "I want an environment with ``swh.provenance``"), and the resulting
+environments to be:
+
+ - frozen (using a consistent, known set of package versions)
+ - kept up to date automatically (for our swh packages, as well as the external
+   dependencies)
+ - tested before publication (at least to a minimal extent, e.g. ensuring that
+   the tests of the declared input modules are successful before tagging an
+   application as ready to deploy)
+
+Packaging Workflow
+------------------
+
+Each standalone application is generated from an input ``requirements.txt``
+file. Out of this, a virtualenv is generated and frozen into a
+``requirements-frozen.txt`` file, which is then used to build container images
+(when associated with a ``Dockerfile`` and an entry point script).
+
+The frozen requirements file can also be used to deploy virtual environments
+directly, e.g. on an existing VM or bare metal server.