feature: add standard set of "ambient" props to context

[toddbaert]

We already need to add the flag_key to the context to improve our bucketing algorithm, see setFlagdProperties in the json_evalutor.

We should consider what other properties could be useful, and add them under some sort of namespace to the context. A list could include:

• currentTimestamp
• a variable indicating if this is an RPC implementation or an in-process implementation?

I kept thinking about things like version (the version of flagd) or connection_type (HTTP vs gRPC), but these would be unreliable and inconsistent between flagd RPC and in-process implementations. We should come up with a list that's relevant to all models, it think.

cc @craigpastro

[beeme1mr]

We should keep the list small until we identify use cases.

[AHB102]

I am new to open source, can I try to resolve this issue ?

#851 (comment)

[toddbaert]

I am new to open source, can I try to resolve this issue ?

Definitely. I would start by first monitoring the progress on the blocking issue, trying to understand those changes, and helping with review.

[AHB102]

Definitely! I will look into it.

[toddbaert]

@AHB102 Are you still interested in doing this? I can assign to you if you'd like. The pre-requisite work is done.

[AHB102]

@AHB102 Are you still interested in doing this? I can assign to you if you'd like. The pre-requisite work is done.

Currently working on something else,I'm sorry I can't work on this.

[toddbaert]

@AHB102 Are you still interested in doing this? I can assign to you if you'd like. The pre-requisite work is done.

Currently working on something else,I'm sorry I can't work on this.

I understand, no problem!

[craigpastro]

Hi @toddbaert. I can finish this off if that is okay. Are you still okay with the properties listed above?

[beeme1mr]

I think we should keep it simple and add more as new use cases emerge. My suggestion would be to start with timestamp for now. That would allow us to create time based flag configurations in a constant way.

In my opinion, we don't need to include current in the name. We can include a full description in the docs.

[craigpastro]

Thank you @beeme1mr. Sounds good. I'll add timestamp for now.