Ran into this today.
The problem I am running into is chicken/egg.
So to successfully run the 2.7 copy of get-pip.py, you need some updated root certs. The easy way to get those updated root certs is to install open SSL.
The way to upgrade openssl is via ipkg, which requires pip. And around and around we go... There's more issues than just this - some install script seems like it has a bad URI, which gets a redirect or something? I haven't dug into the zip file embedded into get-pip.py.
The errors I'm getting are:
Could not fetch URL
https://pypi.org/simple/pip/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='
pypi.org', port=443): Max retries exceeded with url: /simple/pip/ (Caused by SSLError(CertificateError("hostname '
pypi.org' doesn't match u'
www.python.org'",),)) - skipping
ERROR: Could not find a version that satisfies the requirement pip<21.0 (from versions: none)
ERROR: No matching distribution found for pip<21.0
Since I was also using bigger drives now, I ran into a limitation of ipkg, which I had to work around with this guy:
Hope this helps someone! This is probably my last rodeo with my DNS-320 before I replace it with something more modern and powerful.