5f5a11525c
Mainly because it has better support for installing the packages from different python versions. It also has better dependency resolver than Pipenv. And supports modern standard for python dependency management. This includes usage of pyproject.toml for project specific configuration instead of per tool conf files. See following links for details: https://pip.pypa.io/en/stable/reference/build-system/pyproject-toml/ https://www.python.org/dev/peps/pep-0518/
4.3 KiB
Source tree layout
Below you will find a brief overview of each subdir in the source tree in alphabetical order.
/control_plane:
Local control plane. Functions to start, configure and stop pageserver and postgres instances running as a local processes. Intended to be used in integration tests and in CLI tools for local installations.
/docs:
Documentaion of the Zenith features and concepts. Now it is mostly dev documentation.
/monitoring:
TODO
/pageserver:
Zenith storage service. The pageserver has a few different duties:
- Store and manage the data.
- Generate a tarball with files needed to bootstrap ComputeNode.
- Respond to GetPage@LSN requests from the Compute Nodes.
- Receive WAL from the WAL service and decode it.
- Replay WAL that's applicable to the chunks that the Page Server maintains
For more detailed info, see /pageserver/README
/postgres_ffi:
Utility functions for interacting with PostgreSQL file formats. Misc constants, copied from PostgreSQL headers.
/proxy:
Postgres protocol proxy/router. This service listens psql port, can check auth via external service and create new databases and accounts (control plane API in our case).
/test_runner:
Integration tests, written in Python using the pytest framework.
/vendor/postgres:
PostgreSQL source tree, with the modifications needed for Zenith.
/vendor/postgres/contrib/zenith:
PostgreSQL extension that implements storage manager API and network communications with remote page server.
/vendor/postgres/contrib/zenith_test_utils:
PostgreSQL extension that contains functions needed for testing and debugging.
/walkeeper:
The zenith WAL service that receives WAL from a primary compute nodes and streams it to the pageserver. It acts as a holding area and redistribution center for recently generated WAL.
For more detailed info, see /walkeeper/README
/workspace_hack:
The workspace_hack crate exists only to pin down some dependencies.
/zenith
Main entry point for the 'zenith' CLI utility. TODO: Doesn't it belong to control_plane?
/zenith_metrics:
Helpers for exposing Prometheus metrics from the server.
/zenith_utils:
Helpers that are shared between other crates in this repository.
Using Python
Note that Debian/Ubuntu Python packages are stale, as it commonly happens, so manual installation of dependencies is not recommended.
A single virtual environment with all dependencies is described in the single Pipfile.
Prerequisites
- Install Python 3.7 (the minimal supported version) or greater.
- Our setup with poetry should work with newer python versions too. So feel free to open an issue with a
c/test-runnerlabel if something doesnt work as expected. - If you have some trouble with other version you can resolve it by installing Python 3.7 separately, via pyenv or via system package manager e.g.:
# In Ubuntu sudo add-apt-repository ppa:deadsnakes/ppa sudo apt update sudo apt install python3.7
- Our setup with poetry should work with newer python versions too. So feel free to open an issue with a
- Install
poetry- Exact version of
poetryis not important, see installation instructions available at poetry's website`.
- Exact version of
- Install dependencies via
./scripts/pysync. Note that CI uses Python 3.7 so if you have different version some linting tools can yield different result locally vs in the CI.
Run poetry shell to activate the virtual environment.
Alternatively, use poetry run to run a single command in the venv, e.g. poetry run pytest.
Obligatory checks
We force code formatting via yapf and type hints via mypy.
Run the following commands in the repository's root (next to setup.cfg):
poetry run yapf -ri . # All code is reformatted
poetry run mypy . # Ensure there are no typing errors
WARNING: do not run mypy from a directory other than the root of the repository.
Otherwise it will not find its configuration.
Also consider:
- Running
flake8(or a linter of your choice, e.g.pycodestyle) and fixing possible defects, if any. - Adding more type hints to your code to avoid
Any.
Changing dependencies
To add new package or change an existing one you can use poetry add or poetry update or edit pyproject.toml manually. Do not forget to run poetry lock in the latter case.
More details are available in poetry's documentation.