[connector/countconnector] Handle non-string attributes

[lkwronski]

Description:

Adding support for non string attributes in the count connector. I started working based on #30314 (comment), but it doesn't work. When I try to add the type constaint:

type Number interface {
	int64 | float64
}

type AttributeConfig struct {
	Key               string  `mapstructure:"key"`
	DefaultValue      Number  `mapstructure:"default_value"`
}

This causes the following error:

 cannot use type Number outside a type constraint: interface contains type constraints

My idea was to introduce new fields DefaultIntValue and DefaultFloatValue to handle number types, let me know if this makes sense, if so, I will add documentation and finalize this PR.

Link to tracking Issue: Fixes #30314.

Testing: Added unit test

Documentation: TODO

[djaglowski]

I think this design introduces unnecessary relationships between fields in the config. If we cannot use a type constraint, can we just make DefaultValue an any?

[djaglowski]

We need to keep this check, or something equivalent.

[djaglowski]

We need to check if there is a default value set. If not, won't the type switch below panic?

[lkwronski]

Sure, I added panic.

[djaglowski]

We do not rely on panics in the collector. There is no requirement to set a default value, so this is not even a problem. We should just skip the block, like we were doing previously.

[lkwronski]

I hope I understand now. I added a condition to skip if the default value is nil.

[jpkrohling]

Agree with @djaglowski that the panic is out of place. Other than that, I like the solution given to the default value.

[djaglowski]

Thanks @lkwronski