Je m'occupe de quelques serveurs RHEL6 et j'essaie de les configurer pour utiliser un serveur PyPi interne (mandaté par Nexus 3).
Le problème est que notre serveur PyPi interne est l'un des nombreux VHosts SSL sur le même serveur Nginx, et que Python 2.6 n'est pas compatible SNI ; ainsi, easy_install échoue parce qu'il essaie de télécharger à partir de la mauvaise URL Vhost et pip échoue avec SNIMissingWarning et InsecurePlatformWarning.
J'ai consulté les conseils sur https://urllib3.readthedocs.io/en/latest/advanced-usage.html#ssl-warnings mais il semble qu'il s'agisse d'une solution de contournement pour vos propres scripts ; cela ne résout pas les problèmes de Python lui-même. J'ai quand même installé urllib3 et les paquets associés, et le problème persiste.
[root@foo.internal ~]# pip install --index https://nexus3.internal/repository/pypi-proxy/simple twine
DEPRECATION: Python 2.6 is no longer supported by the Python core team, please upgrade your Python. A future version of pip will drop support for Python 2.6
Collecting twine
/usr/lib/python2.6/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:318: SNIMissingWarning: An HTTPS request has been made, but the SNI (Subject Name Indication) extension to TLS is not available on this platform. This may cause the server to present an incorrect TLS certificate, which can cause validation failures. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/security.html#snimissingwarning.
SNIMissingWarning
/usr/lib/python2.6/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:122: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/security.html#insecureplatformwarning.
InsecurePlatformWarning
Could not fetch URL https://nexus3.internal/repository/pypi-proxy/simple/twine/: There was a problem confirming the ssl certificate: [Errno 1] _ssl.c:490: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed - skipping
Could not find a version that satisfies the requirement twine (from versions: )
No matching distribution found for twine
