Merge pull request #183 from influxdata/tm/configure-cpython

feat: configure cpython source

Author: Sl1mb0

guests/python/Justfile

@@ -11,6 +11,11 @@ SHA256_WASI_SDK_SYSROOT := "35172f7d2799485b15a46b1d87f50a585d915ec662080f005d99
 
 PYTHON_VERSION_FULL := PYTHON_VERSION_MAJOR + "." + PYTHON_VERSION_MINOR + "." + PYTHON_VERSION_MICRO
 
+# Configurable URLs for Python SDK downloads (with defaults)
+PYTHON_SDK_BASE_URL := env_var_or_default("PYTHON_SDK_BASE_URL", "https://github.com/brettcannon/cpython-wasi-build/releases/download")
+PYTHON_SDK_URL := env_var_or_default("PYTHON_SDK_URL", PYTHON_SDK_BASE_URL + "/v" + PYTHON_VERSION_FULL + "/python-" + PYTHON_VERSION_FULL + "-wasi_sdk-" + WASI_SDK_VERSION_MAJOR + ".zip")
+BUILD_PYTHON_SDK_URL := env_var_or_default("BUILD_PYTHON_SDK_URL", PYTHON_SDK_BASE_URL + "/v" + PYTHON_VERSION_FULL + "/_build-python-" + PYTHON_VERSION_FULL + "-wasi_sdk-" + WASI_SDK_VERSION_MAJOR + ".zip")
+
 DOWNLOADS_DIR := source_directory() / "downloads"
 
 export PYO3_CROSS_PYTHON_VERSION := PYTHON_VERSION_MAJOR + "." + PYTHON_VERSION_MINOR
@@ -49,7 +54,7 @@ download-python-sdk:
         --tlsv1.2 \
         --location \
         --output "python-sdk.zip" \
-        "https://github.com/brettcannon/cpython-wasi-build/releases/download/v{{PYTHON_VERSION_FULL}}/python-{{PYTHON_VERSION_FULL}}-wasi_sdk-{{WASI_SDK_VERSION_MAJOR}}.zip"
+        "{{PYTHON_SDK_URL}}"
 
     curl \
         --fail \
@@ -59,7 +64,7 @@ download-python-sdk:
         --tlsv1.2 \
         --location \
         --output "build-python-sdk.zip" \
-        "https://github.com/brettcannon/cpython-wasi-build/releases/download/v{{PYTHON_VERSION_FULL}}/_build-python-{{PYTHON_VERSION_FULL}}-wasi_sdk-{{WASI_SDK_VERSION_MAJOR}}.zip"
+        "{{BUILD_PYTHON_SDK_URL}}"
 
     echo "{{SHA256_PYTHON_SDK}} python-sdk.zip" | sha256sum -c
     echo "{{SHA256_PYTHON_SDK_BUILD}} build-python-sdk.zip" | sha256sum -c

guests/python/README.md

@@ -16,6 +16,35 @@ just build-release
 ## Python Version
 We currently bundle [Python 3.14.0], [build for WASI](https://docs.python.org/3/library/intro.html#webassembly-platforms).
 
+## Custom CPython Configuration
+You can configure the build to use a custom CPython source by setting the following environment variables:
+
+
+- `PYTHON_SDK_BASE_URL`: Base URL to download the Python WASI SDK artifacts. This
+  should point to a location containing both the main SDK archive and the build
+  artifacts archive.
+- `PYTHON_SDK_URL`: URL to download the main Python WASI SDK archive. This
+  should point to an artifact containing the pre-built Python runtime and
+  standard library for WASI. Will override `PYTHON_SDK_BASE_URL` if set.
+- `BUILD_PYTHON_SDK_URL`: URL to download the build artifacts archive. This
+  should point to an artifact containing the compiled Python libraries (like
+  `libpython3.14.a`, `libmpdec.a`, etc.) needed for static linking. Will override
+  `PYTHON_SDK_BASE_URL` if set.
+
+If these environment variables are not set, the build will use the default URLs pointing to the official [CPython WASI build releases](https://github.com/brettcannon/cpython-wasi-build/releases).
+
+Example usage:
+```console
+export PYTHON_SDK_URL="https://example.com/custom-python-sdk.zip"
+export BUILD_PYTHON_SDK_URL="https://example.com/custom-build-python-sdk.zip"
+just build-debug
+
+# Or
+
+export PYTHON_SDK_BASE_URL="https://example.com/custom-python-sdk-base/"
+just build-debug
+```
+
 ## Python Standard Library
 In contrast to a normal Python installation there are a few notable public[^public] modules **missing** from the [Python Standard Library]: