Add Python script for cibuildwheel before_all block

Author: molinav

.github/workflows/run_before_all.py

@@ -0,0 +1,37 @@
+#! /usr/bin/env python
+"""Helper script to be run by `cibuildwheel` as `before_all` step."""
+
+import os
+import sys
+
+HERE = os.path.abspath(__file__)
+ROOT = os.path.dirname(os.path.dirname(os.path.dirname(HERE)))
+sys.path.insert(0, os.path.join(ROOT, "packages", "basemap"))
+import utils  # noqa: E402  # pylint: disable=imports
+
+
+def main():
+    """Build the GEOS library based on parsed environment variables."""
+
+    geos_version = os.environ.get("GEOS_VERSION", None)
+    if geos_version is None:
+        raise ValueError("Undefined environment variable GEOS_VERSION")
+
+    geos_dir = os.environ.get("GEOS_DIR", None)
+    if geos_dir is None:
+        raise ValueError("Undefined environment variable GEOS_DIR")
+
+    geos_njobs = int(os.environ.get("GEOS_NJOBS", 1))
+
+    # pylint: disable=consider-using-f-string
+    print("Running before_all script with the following settings:")
+    print("GEOS_DIR: {0}".format(geos_dir))
+    print("GEOS_VERSION: {0}".format(geos_version))
+    print("GEOS_NJOBS: {0}".format(geos_njobs))
+
+    utils.GeosLibrary(geos_version).build(geos_dir, njobs=geos_njobs)
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())