[BUG] Salt 3004 is not compatible with slackclient 2.x or higher

[sdklein]

Description
Salt 3004 is not compatible with slackclient 2.x or higher but it was installed by default. Must use slackclient==1.3.1.

Per https://github.com/slackapi/python-slack-sdk/wiki/Migrating-to-2.x, the slack client usage has changed considerably. For instance, the import here no longer work and has to be changed. https://github.com/saltstack/salt/blob/master/salt/engines/slack.py#L169

The simple fix is to make sure the slackclient is pinned appropriately.

However as of today the entire legacy RTM methodology will no longer work for any new slack bots. More information about that can be found here: https://api.slack.com/changelog/2021-10-rtm-start-to-stop. This is going to require the entire slack engine and supporting libraries to be upgraded.

Setup
Install salt master 3004, configure slack engine.
Slack engine will not start. Error printed is:
Could not LazyLoad slack.start: 'slack' __virtual__ returned False: The 'slackclient' Python module could not be loaded

Please be as specific as possible and give set-up details.

• on-prem machine
• VM (Virtualbox, KVM, etc. please specify)
• VM running on a cloud service, please be explicit and add details
• container (Kubernetes, Docker, containerd, etc. please specify)
• or a combination, please be explicit
• jails if it is FreeBSD

Steps to Reproduce the behavior
Install salt 3004 and attempt to configure the slack engine. It will not start.

Expected behavior
slack engine should start

Versions Report

salt --versions-report

(Provided by running salt --versions-report. Please also mention any differences in master/minion versions.)

Salt Version:
          Salt: 3004
 
Dependency Versions:
          cffi: 1.12.3
      cherrypy: Not Installed
      dateutil: 2.8.2
     docker-py: Not Installed
         gitdb: 4.0.9
     gitpython: 3.1.20
        Jinja2: 2.11.1
       libgit2: 0.28.2
      M2Crypto: 0.35.2
          Mako: Not Installed
       msgpack: 0.6.2
  msgpack-pure: Not Installed
  mysql-python: Not Installed
     pycparser: 2.19
      pycrypto: Not Installed
  pycryptodome: Not Installed
        pygit2: 0.28.2
        Python: 3.6.8 (default, Apr  2 2020, 13:34:55)
  python-gnupg: Not Installed
        PyYAML: 3.13
         PyZMQ: 17.0.0
         smmap: 5.0.0
       timelib: Not Installed
       Tornado: 4.5.3
           ZMQ: 4.1.4
 
System Versions:
          dist: centos 7 Core
        locale: UTF-8
       machine: x86_64
       release: 3.10.0-957.12.1.el7.x86_64
        system: Linux
       version: CentOS Linux 7 Core

[welcome]

Hi there! Welcome to the Salt Community! Thank you for making your first contribution. We have a lengthy process for issues and PRs. Someone from the Core Team will follow up as soon as possible. In the meantime, here’s some information that may help as you continue your Salt journey.
Please be sure to review our Code of Conduct. Also, check out some of our community resources including:

• Community Wiki
• Salt’s Contributor Guide
• Join our Community Slack
• IRC on LiberaChat
• Salt Project YouTube channel
• Salt Project Twitch channel

There are lots of ways to get involved in our community. Every month, there are around a dozen opportunities to meet with other contributors and the Salt Core team and collaborate in real time. The best way to keep track is by subscribing to the Salt Community Events Calendar.
If you have additional questions, email us at saltproject@vmware.com. We’re glad you’ve joined our community and look forward to doing awesome things with you!

[OrangeDog]

Possible duplicate of #57842.
Can you also update the issue title so it mentions what the issue it?

[garethgreenaway]

Closing this one because it's a duplicate of #57842