Prometheus exporter sanitize info metric

[kornerc]

Description

The Prometheus Exporter did not sanitize the info metric.
This might prevent successful scraping from Prometheus when having, for example, dots in an attribute.

Fixes #3571 and #3563

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Unit test test_target_info_sanitize which checks if a character like a dot . in an attribute name is translated to an underscore _.

Does This PR Require a Contrib Repo Change?

• No.

Checklist:

• Followed the style guidelines of this project
• Changelogs have been updated
• Unit tests have been added
• Documentation has been updated

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: kornerc / name: Clemens Korner (d1c331c, 60d505b, e556234, 170647e)
• ✅ login: ocelotl / name: Diego Hurtado (6309f42)

[kornerc]

PR is ready for review.

I think there is no need to update the documentation, nonetheless, I left in the checklist Documentation has been updated unchecked.

During the fix I found another issue in a test:

opentelemetry-python/exporter/opentelemetry-exporter-prometheus/tests/test_prometheus_exporter.py

Line 361 in 3dfe224

for prometheus_metric in result[:0]:

Parts of the test are not executed because result[:0] returns an empty list, instead it should be something like prometheus_metric = result[0].
But I guess it is better to make a separate issue and PR for this (I can do that).

[Jdsleppy]

@kornerc It looks like linting failed because black formatting was not applied. You can check this locally using

pip install tox==3.27.1
tox -e lint

To fix, you can use

pip install -r dev-requirements.txt
python -m black .

I'm now looking into the other CI failure to see how to fix it.

[Jdsleppy]

@kornerc It seems like the only other error was unrelated:

ERROR:   py37-test-instrumentation-falcon3: commands failed

So we can probably get this reviewed after linting is fixed.

[aabmass]

Thanks for the PR!

[kornerc]

@kornerc It looks like linting failed because black formatting was not applied. You can check this locally using

pip install tox==3.27.1
tox -e lint

To fix, you can use

pip install -r dev-requirements.txt
python -m black .

I'm now looking into the other CI failure to see how to fix it.

@Jdsleppy thanks for the feedback and the info!

In 170647e I reformattet the code and tox -e lint does not complain anymore about the formatting.