Activate slow query log in MySQL test setup

[florimondmanca]

What does this PR do?

Activate and configure slow query logs for the MySQL Docker Compose setup (for both MySQL and MariaDB flavors).

Motivation

This makes it much easier to test slow query logs locally. I essentially got tired of having to do the setup manually. :-)

Additional Notes

/

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• PR title must be written as a CHANGELOG entry (see why)
• Files changes must correspond to the primary purpose of the PR as described in the title (small unrelated changes should have their own PR)
• PR must have changelog/ and integration/ labels attached

[florimondmanca]

Note to reviewers: I had to upgrade the image version because of a bug in the RC1 we were using - it wasn't able to read the my_custom.conf config file properly due to a permission error.

[florimondmanca]

Note to reviewers: list of supported config files are documented here (table 4.2).

[florimondmanca]

Note to reviewers: the path to this config file is officially documented here.

[AlexandreYang]

💯

Just a comment about documentation.

[mgarabed]

While this will configure MySQL env to export and generate slow log reports, how does the agent get configured? There are some additional config files that need to be updated on the agent container. Maybe there needs to be another PR to handle broader log support via a ddev env start option or flag?

[codecov]

Codecov Report

Merging #5186 into master will decrease coverage by 10.56%.
The diff coverage is 66.66%.

Impacted Files	Coverage Δ
mysql/tests/conftest.py	92.95% <66.66%> (ø)
vertica/tests/metrics.py
...checks_dev/tests/plugin/test_environment_runner.py
riakcs/datadog_checks/riakcs/riakcs.py
oracle/tests/test_oracle.py
...r/datadog_checks/openstack_controller/__about__.py
twistlock/datadog_checks/twistlock/twistlock.py
linkerd/datadog_checks/linkerd/linkerd.py
...oller/datadog_checks/openstack_controller/utils.py
istio/tests/test_e2e.py
... and 873 more

[florimondmanca]

Thanks for the reviews! I pushed fixes in the latest commits.

@mgarabed

how does the agent get configured?

Log collection by the agent is not automatically configured, indeed — the logs section of the conf.yaml file should contain an entry for the slow log. For MySQL this is already documented: both the conf.yaml.example file as well as the README.md document this, e.g.:

logs:
  # ...
  - type: file
    path: /var/log/mysql/mysql-slow.log
    source: mysql
    sourcecategory: database
    service: myapplication

For development, I believe we don't need the Agent to collect logs, though. I went away with grabbing the output from the slow logs (e.g. in this case, using a tail command on the log file within the MySQL leader container), and using them as unit test cases for the log parser. Or is there something I'm missing?

[AlexandreYang]

Looks good to me overall.

Just a nit below.