Namespace tag the disruptions.gauge metric

[ptnapoleon]

What does this PR do?

• Adds new functionality
• Alters existing functionality
• Fixes a bug
• Improves documentation or testing

Please briefly describe your changes as well as the motivation behind them:

• Users want a metric to see how many disruptions are running in their namespace. They can sort of do so with ongoing_duration, but that's a bit indirect. They should be able to check the disruptions.gauge and filter by a tag on their namespace.
• We don't currently tag disruptions.gauge at all. I've added a namespace tag

Code Quality Checklist

• The documentation is up to date.
• My code is sufficiently commented and passes continuous integration checks.
• I have signed my commit (see Contributing Docs).

Testing

• I leveraged continuous integration testing
  • by depending on existing unit tests or end-to-end tests.
  • by adding new unit tests or end-to-end tests.
• I manually tested the following steps:
  • x
  • locally.
  • as a canary deployment to a cluster.

[datadog-datadog-prod-us1]

Datadog Report

Branch report: philip/namespace-tag-on-gauge
Commit report: cd7a088
Test service: chaos-controller

✅ 0 Failed, 720 Passed, 2 Skipped, 7m 13.45s Wall Time

[ptnapoleon]

I've confirmed this works! the namespace tag for this metric now lists the number of disruptions in that namespace, no longer attributing them all to chaos-engineering

[ptnapoleon]

I've tested and this works in the case of 0 disruptions, disruptions in 1 namespace, and disruptions in many namespaces

[clairecng]

👍