Basic structure of indexurl

Author: thatch

README.md

@@ -1,6 +1,12 @@
 # indexurl
 
+This is a super-simple project to read the global.index-url config value of pip
+without extra processes.
 
+```py
+from indexurl import get_index_url
+print(get_index_url())
+```
 
 # License
 

indexurl/__init__.py

@@ -0,0 +1,8 @@
+"""
+This is a trivial package to find a likely index_url given current system
+configuration.
+"""
+
+from .core import get_index_url
+
+__all__ = ["get_index_url"]

indexurl/core.py

@@ -0,0 +1,70 @@
+import logging
+import os
+from configparser import RawConfigParser
+from pathlib import Path
+from typing import Optional
+
+import appdirs
+
+LOG = logging.getLogger(__name__)
+
+DEFAULT_INDEX_URL = "https://pypi.org/simple"
+
+
+def get_index_url() -> str:
+    """
+    Returns the configured (or default) value of global.index-url
+
+    For most intents this matches the value of `pip config get global.index-url`
+    except it works with older versions of pip, has the default in a common
+    place, normalizes the trailing slash away, and doesn't require another
+    process or pip to be installed.
+    """
+    # There are a lot of places this can live.
+    # See https://pip.pypa.io/en/stable/topics/configuration/#location
+    #
+    # Note that we look at them in _reverse_ order so we can stop as soon as the
+    # key is found.
+
+    virtual_env = os.getenv("VIRTUAL_ENV")
+    pip_config_file = os.getenv("PIP_CONFIG_FILE")
+    xdg_config_dirs = os.getenv("XDG_CONFIG_DIRS", "").split(",")
+    if pip_config_file == "os.devnull":
+        return DEFAULT_INDEX_URL
+
+    for option in [
+        # Site
+        Path(virtual_env, "pip.conf") if virtual_env else None,
+        # User
+        Path(appdirs.user_config_dir("pip"), "pip.conf"),  # omit some Mac logic
+        # Global
+        Path("/etc/pip.conf"),
+        *(Path(d, "pip", "pip.conf") for d in xdg_config_dirs),
+        # Env
+        Path(pip_config_file) if pip_config_file else None,
+    ]:
+        if option is not None:
+            index_url = _get_global_index_url_from_file(option)
+            if index_url:
+                return index_url.rstrip("/")
+
+    return DEFAULT_INDEX_URL
+
+
+def _get_global_index_url_from_file(path: Path) -> Optional[str]:
+    """
+    Returns the global.index-url, or None.  Logs an error message if file exists
+    but is invalid or unreadable.
+    """
+    if not path.exists():
+        return None
+    config = RawConfigParser()
+    try:
+        config.read(path)
+    except Exception as e:
+        LOG.warning("Config %s could not be read: %s", path, repr(e))
+    return config.get("global", "index-url", fallback=None)
+
+
+if __name__ == "__main__":  # pragma: no cover
+    print(get_index_url())

indexurl/tests/__init__.py

@@ -1,5 +1,5 @@
-# from .foo import FooTest
+from .core import IndexUrlTest
 
 __all__ = [
-    # "FooTest",
+    "IndexUrlTest",
 ]

indexurl/tests/core.py

@@ -0,0 +1,74 @@
+import os
+import tempfile
+import unittest
+from contextlib import contextmanager
+from pathlib import Path
+from typing import Generator
+
+from ..core import _get_global_index_url_from_file, get_index_url
+
+
+@contextmanager
+def patch_env(var: str, value: str) -> Generator[None, None, None]:
+    old_value = os.getenv(var)
+    os.environ[var] = value
+    yield
+    if old_value is None:
+        del os.environ[var]
+    else:
+        os.environ[var] = old_value
+
+
+class IndexUrlTest(unittest.TestCase):
+    def test_basic_reading(self) -> None:
+        with tempfile.TemporaryDirectory() as d:
+            p = Path(d, "a.ini")
+            self.assertEqual(None, _get_global_index_url_from_file(p))
+            p.write_text("")
+            self.assertEqual(None, _get_global_index_url_from_file(p))
+            p.write_text("[global]\n")
+            self.assertEqual(None, _get_global_index_url_from_file(p))
+            p.write_text("[global]\nfoo=a\n")
+            self.assertEqual(None, _get_global_index_url_from_file(p))
+
+            p.write_text("[global]\nindex-url=a")
+            self.assertEqual("a", _get_global_index_url_from_file(p))
+            p.write_text("[global]\nindex-url = a\n")
+            self.assertEqual("a", _get_global_index_url_from_file(p))
+            p.write_text("[global]\nindex-url = a\r\n")
+            self.assertEqual("a", _get_global_index_url_from_file(p))
+            p.write_text("]")
+            self.assertEqual(None, _get_global_index_url_from_file(p))
+
+    def test_pip_config_file(self) -> None:
+        with tempfile.TemporaryDirectory() as d:
+            Path(d, "pip.conf").write_text("[global]\nindex-url=a\n")
+            Path(d, "pip.t").write_text("[global]\nindex-url=t\n")
+            with patch_env("PIP_CONFIG_FILE", str(Path(d, "pip.t"))):
+                self.assertEqual("t", get_index_url())
+                with patch_env("VIRTUAL_ENV", d):
+                    self.assertEqual("a", get_index_url())
+            with patch_env("PIP_CONFIG_FILE", "os.devnull"), patch_env(
+                "VIRTUAL_ENV", d
+            ):
+                self.assertEqual("https://pypi.org/simple", get_index_url())
+
+    def test_virtual_env(self) -> None:
+        with tempfile.TemporaryDirectory() as d:
+            Path(d, "pip.conf").write_text("[global]\nindex-url=a\n")
+            with patch_env("VIRTUAL_ENV", d):
+                self.assertEqual("a", get_index_url())
+
+    # This one only makes sense on *nix
+    def test_xdg_config_dirs(self) -> None:
+        with tempfile.TemporaryDirectory() as d:
+            with patch_env("XDG_CONFIG_DIRS", f"{d},"):
+                Path(d, "pip").mkdir()
+                Path(d, "pip", "pip.conf").write_text("[global]\nindex-url=a\n")
+                self.assertEqual("a", get_index_url())
+
+    def test_fallback(self) -> None:
+        with patch_env("VIRTUAL_ENV", ""), patch_env("XDG_CONFIG_DIRS", ""), patch_env(
+            "HOME", ""
+        ), patch_env("XDG_CONFIG_HOME", ""), patch_env("PIP_CONFIG_FILE", ""):
+            self.assertEqual("https://pypi.org/simple", get_index_url())

setup.cfg

@@ -16,6 +16,7 @@ setup_requires =
 python_requires = >=3.10
 include_package_data = true
 install_requires =
+    appdirs >= 1.3.0
 
 [options.extras_require]
 dev =