poetry2nix/fetch_from_legacy.py
Joël Perras f26abf3d92 Parse pypi source indexes with basic auth creds
This change parses the `index_url` of the source and extracts out the
Basic Authentication `username` and `password` credentials, if they
exist, to be used by the existing mechanism for netrc parsing.

The `index_url` is then reconstructed without the credentials, so that
the rest of the index fetch can proceed as expected.

Details
=======

Previously, if one had a `pyproject.toml` with a custom source that had
basic auth credentials in the URL, e.g.

```toml
[[tool.poetry.source]]
name = "private_source"
url = "https://username:password@pypi.example.com/pypi"
```

The `fetch_from_legacy.py` script would fail to parse, erronously
splitting on the `:` thinking that whatever came after it was a numeric
port identifier ala `https://example.com:8080`.

While embedding authentication credentials in an index URL that is then
committed to a `pyproject.toml` is not what one would consider best
practice (there are several alternative approaches that keep credentials
out of the `pyproject.toml` file), it _is_ supported by the direct usage
of Poetry, and those legacy projects should still be able to utilize
`poetry2nix`.
2022-12-13 11:56:11 -05:00

134 lines
3.8 KiB
Python

# Some repositories (such as Devpi) expose the Pypi legacy API
# (https://warehouse.pypa.io/api-reference/legacy.html).
#
# Note it is not possible to use pip
# https://discuss.python.org/t/pip-download-just-the-source-packages-no-building-no-metadata-etc/4651/12
import os
import sys
import netrc
from urllib.parse import urlparse, urlunparse
from html.parser import HTMLParser
import urllib.request
import shutil
import ssl
from os.path import normpath
# Parse the legacy index page to extract the href and package names
class Pep503(HTMLParser):
def __init__(self):
super().__init__()
self.sources = {}
self.url = None
self.name = None
def handle_data(self, data):
if self.url is not None:
self.name = data
def handle_starttag(self, tag, attrs):
if tag == "a":
for name, value in attrs:
if name == "href":
self.url = value
def handle_endtag(self, tag):
if self.url is not None:
self.sources[self.name] = self.url
self.url = None
url = sys.argv[1]
package_name = sys.argv[2]
index_url = url + "/" + package_name + "/"
package_filename = sys.argv[3]
# Parse username and password for this host from the netrc file if given.
username, password = None, None
if os.environ["NETRC"]:
netrc_obj = netrc.netrc(os.environ["NETRC"])
host = urlparse(index_url).netloc
# Strip port number if present
if ":" in host:
host = host.split(":")[0]
username, _, password = netrc_obj.authenticators(host)
print("Reading index %s" % index_url)
context = ssl.create_default_context()
context.check_hostname = False
context.verify_mode = ssl.CERT_NONE
# Extract out username/password from index_url, if present.
parsed_url = urlparse(index_url)
username = parsed_url.username or username
password = parsed_url.password or password
index_url = parsed_url._replace(netloc=parsed_url.netloc.rpartition("@")[-1]).geturl()
req = urllib.request.Request(index_url)
if username and password:
import base64
password_b64 = base64.b64encode(":".join((username, password)).encode()).decode(
"utf-8"
)
req.add_header("Authorization", "Basic {}".format(password_b64))
response = urllib.request.urlopen(req, context=context)
index = response.read()
parser = Pep503()
parser.feed(str(index))
if package_filename not in parser.sources:
print(
"The file %s has not be found in the index %s" % (package_filename, index_url)
)
exit(1)
package_file = open(package_filename, "wb")
# Sometimes the href is a relative or absolute path within the index's domain.
indicated_url = urlparse(parser.sources[package_filename])
if indicated_url.netloc == "":
parsed_url = urlparse(index_url)
if indicated_url.path.startswith("/"):
# An absolute path within the index's domain.
path = parser.sources[package_filename]
else:
# A relative path.
path = parsed_url.path + "/" + parser.sources[package_filename]
package_url = urlunparse(
(
parsed_url.scheme,
parsed_url.netloc,
path,
None,
None,
None,
)
)
else:
package_url = parser.sources[package_filename]
# Handle urls containing "../"
parsed_url = urlparse(package_url)
real_package_url = urlunparse(
(
parsed_url.scheme,
parsed_url.netloc,
normpath(parsed_url.path),
parsed_url.params,
parsed_url.query,
parsed_url.fragment,
)
)
print("Downloading %s" % real_package_url)
req = urllib.request.Request(real_package_url)
if username and password:
req.add_unredirected_header("Authorization", "Basic {}".format(password_b64))
response = urllib.request.urlopen(req, context=context)
with response as r:
shutil.copyfileobj(r, package_file)