move to python3

[beardeddog]

move to python3

[noahv]

Just curious why is this needed?

Can we just let the user decide which python to use? I am using pyenv to point to python3 when I need a more recent version of python.

If we want to change the default for all users on a given cluster then there is a utility called update-alternatives that will modify the soft links.

[Wed Oct 23 12:56:50 noah@uan1:~] ls -l /usr/bin/ |grep python lrwxrwxrwx 1 root root 9 Aug 7 10:01 python -> python2.7

[jsquyres]

This might be a good reason: https://pythonclock.org/

[beardeddog]

I've been told

/usr/bin/python has been removed in SLES 15 SP1, and only /usr/bin/python3
is available by-default:
https://www.suse.com/releasenotes/x86_64/SUSE-SLES/15-SP1/#Packages.Modules

so you can rely on python being set

pyenv works great for development, I use it to, not sure how it maps in production where I land processes that are being run by others or by root or by cron ...

the real question is "what is keeping us on python2?"

[noahv]

I am not aware of any outstanding issues that are keeping us on python2.

Can we wait until we run a cycle on our Intel SLES15.1 cluster using python3 before making the change?

I do see /usr/bin/python installed from the python-base from sles_15.1_updates which seems to contradict the release notes you mentioned. Not sure about that one!

[Wed Oct 23 13:21:22 noah@uan1:sles_15.1_updates] zypper wp /usr/bin/python
Command 'what-provides' is replaced by 'search --provides --match-exact'.
See 'help search' for all available options.
Loading repository data...
Reading installed packages...

S | Name        | Summary                         | Type
--+-------------+---------------------------------+--------
i | python-base | Python Interpreter base package | package

[Wed Oct 23 13:22:49 noah@uan1:sles_15.1_updates] zypper search -s python-base
Loading repository data...
Reading installed packages...

S | Name        | Type    | Version       | Arch   | Repository
--+-------------+---------+---------------+--------+------------------
i | python-base | package | 2.7.14-7.17.1 | x86_64 | sles_15.1_updates

[Wed Oct 23 13:21:52 noah@uan1:sles_15.1_updates] sudo zypper install -d --force python-base
Loading repository data...
Reading installed packages...
Forcing installation of 'python-base-2.7.14-7.17.1.x86_64' from repository 'sles_15.1_updates'.
Resolving package dependencies...

The following package is going to be reinstalled:
  python-base

The following package has no support information from its vendor:
  python-base

1 package to reinstall.
Overall download size: 0 B. Already cached: 5.6 MiB. Download only.
Continue? [y/n/v/...? shows all options] (y): y
In cache python-base-2.7.14-7.17.1.x86_64.rpm                                                                                                   (1/1),   5.6 MiB ( 23.2 MiB unpacked)

[Wed Oct 23 13:22:06 noah@uan1:sles_15.1_updates] rpm -qpl /var/cache/zypp/packages/sles_15.1_updates/python-base-2.7.14-7.17.1.x86_64.rpm
warning: /var/cache/zypp/packages/sles_15.1_updates/python-base-2.7.14-7.17.1.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID 39db7c82: NOKEY
/etc/rpm/macros.python2
/usr/bin/pydoc
/usr/bin/python

[beardeddog]

@hppritcha @jjhursey any concerns with moving to pymtt to python3 ?

[jjhursey]

No objection from me, but I'm not actively using this part of the tool. I think moving to python3 is generally where we want to be.

[hppritcha]

@beardeddog no. I only use python3 when using MTT. However, I am definitely not using all modules so may not be detecting some python2ishness.

[hppritcha]

@beardeddog can this be closed now since #886 was merged into master?

[beardeddog]

yes, closing