Add support for SASL_PLAINTEXT authentication with Kafka broker

[PHameete]

What does this PR do?

Add support for SASL Plaintext authentication with the Kafka broker to the kafka_consumer integration. This uses properties already available on the used KafkaClient.

Motivation

It was currently only possible to use PLAINTEXT or SSL. This makes it possible to also connect to a Kafka broker using SASL_PLAINTEXT. The KafkaClient does not support SASL_SSL yet unfortunately.

Review checklist

• [] PR has a meaningful title or PR has the no-changelog label attached
• Feature or bugfix has tests
• Git history is clean
• If PR impacts documentation, docs team has been notified or an issue has been opened on the documentation repo
• If PR adds a configuration option, it has been added to the configuration file.

[dabcoder]

@PHameete Thanks for the PR. Tests are failing though, this is flake8 update related - recent updates (https://pypi.org/project/flake8/#history). Can you merge the master branch into yours, which should allow those tests to pass?

[codecov-io]

Codecov Report

Merging #3056 into master will decrease coverage by 5.37%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #3056      +/-   ##
==========================================
- Coverage   84.03%   78.65%   -5.38%     
==========================================
  Files         648        8     -640     
  Lines       36033      520   -35513     
  Branches     4352      110    -4242     
==========================================
- Hits        30279      409   -29870     
+ Misses       4482       79    -4403     
+ Partials     1272       32    -1240

[PHameete]

@dabcoder ty for getting back to me. I did the merge as requested.

[gzussa]

@PHameete Thanks a lot for this contribution. 💯
This is a good catch!

After looking at the client doc, it seems that we are missing quite a lot of config in there.
Would you be able to add them all?
Also, are sasl_* params global to all *_connect_str or do you think they should be specific?
ssl_* config seems to be global so my guess is that sasl params should be the same but you may know better.

Also, would you mind to format the config file based on this convention. @l0k0ms should be able to assist you there.

[PHameete]

@gzussa I've added all authentication parameters (SSL, SASL, Kerberos) that were missing on the datadog integration side, and example config according to the example you provided. It seems a bit overkill to add all the timeouts and buffer sizes.

Regarding the sasl: I dont think they are global.

[dabcoder]

@PHameete Thanks, and apologies for the delay, we are still looking into the codecov/project failure there, we'll get back to you as soon as possible.

[PHameete]

@dabcoder not a problem, let me know if you need anything!

[l0k0ms]

Plop, many thanks for the PR. 🙇
Note for later @DataDog/baklava will need to do a refactoring of the configuration file once this PR is merged, there a lots of nits to update. Creating a card on our internal board to keep this under our radar.

[gzussa]

Looks good to me. Thanks for your contribution 💯