Add a service_blacklist configuration to ensure certain services never have metrics collected

[TylerLubeck]

…r have metrics collected.

Closes #1186

What does this PR do?

Addsa service_blacklist configuration to ensure certain services never have metrics collected

Motivation

I was on a role making consul changes and saw #1186 so I tackled it

Versioning

• Updated CHANGELOG.md. Please use Unreleased as the date in the title

[ofek]

@TylerLubeck Hello there! Would you mind rebasing and using the new filter utility that was introduced in #1510?

I really appreciate it 🙇

[masci]

For blacklisting, can you use this function that was just added in the base check? https://github.com/DataDog/integrations-core/blob/master/datadog_checks_base/datadog_checks/utils/common.py#L14 We're trying to consolidate the way we do this across the whole codebase.

[TylerLubeck]

I can, but I think either there's a bug in that function or it doesn't do quite what we would need here:

https://github.com/DataDog/integrations-core/blob/master/datadog_checks_base/datadog_checks/utils/common.py#L47

I think that in the case that there's a blacklist, then the items have the blacklisted items removed but they're not restricted to just the whitelisted items.

[TylerLubeck]

Copying out of a closed comment thread:

I can use the pattern_filter function, but I think either there's a bug in that function or it doesn't do quite what we would need here:

https://github.com/DataDog/integrations-core/blob/master/datadog_checks_base/datadog_checks/utils/common.py#L47

I think that in the case that there's a blacklist, then the items have the blacklisted items removed but they're not restricted to just the whitelisted items.

I've pushed up the code change to start using the function anyway, if only for the sake of not neglecting this for a week

[masci]

@ofek can you chime in?

[ofek]

@TylerLubeck You can chain the function one type of list at a time.

That is not a bug btw, but rather some tricky membership logic: the only way to use a WL/BL at the same time without either being completely ignored is by applying the BL without members of the WL.

[stale]

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[ofek]

Resolved by #2174