pip: cert failed, but curl works

Question

We installed the our root cert on the client, and the https connection works for curl.

But if we try to use pip, it fails:

Answer 1

I use:

export PIP_CERT=`python -m pip._vendor.requests.certs`

pip install pep8

PIP always validates the certificate of HTTPS connections (and all pypi packages redirect to HTTPS).

The algorithm for determining the CA file is based on 3 steps:

1. Look in a list of default locations for different linux distributions (in my case this file turned out to be out of date, as I am building on a very old linux distribution)
2. If available, override the value found in (1) from a value in the pip.conf file, the environment or the command-line (in that order),
3. If both (1) and (2) did not result in a value, use a bundled file

Note that pip does not use the default SSL directories and files (from ssl.get_default_verify_paths()). But only supports a bundled CA file.

PIP does support a command-line action to list the bundled file from step 3 and that is what I use for this answer.