Vector: Support configuration in JSON

[sam701]

Vector configuration file(s) can get very large and so difficult to look through and maintain. I would like to generate the vector configuration, e.g. by using some configuration languages like dhall or jsonnet. Most of the configuration languages can generate JSON but not (yet) TOML. It would be helpful if the --config flag supports files in JSON format, as well.

[binarylogic]

Thanks @sam701. We agree. We are considering other formats and will update as we obtain consensus.

Ref https://github.com/timberio/vector/issues/1327.

[avalenn]

@sam701 Some have already tried the jsonnet way with current TOML format https://github.com/xunleii/vector_jsonnet

[binarylogic]

@jamtur01 I'd like to prioritize this since it'll allow the use of many different configuration tools like jsonnet, cue, etc. From what I understand this should be pretty easy. Agree?

[jamtur01]

I think it should be easy but I'd like @lukesteensen to weigh in.

I also have UX/UI concerns and questions but that's probably answerable in an implementation. I presume we plan to keep TOML too?

[lukesteensen]

I presume we plan to keep TOML too?

That was my thought. We can keep the existing human-facing interface, docs examples, etc in TOML and simply add another flag that accepts config via JSON and position it to be used with config generation tools.