Bug 1507521 - Finish library per RFC 128

[djmitche]

Manage manifests, reference documents, schemas, and metaschemas as
described in RFC 128.

Intended uses of this library:

• tc-references' build process will create a serializable version and cache that, then on startup will read that and write out a uri-structured format for nginx to serve
• services will use this (with an additional fromService({schemaset, builder, exchanges}) method) to check their schemas and references are valid at test time
• tc-web will use this (somehow, maybe just during build?) to gather up all of the schemas and references for display under /docs

[djmitche]

Hm, actually I want to refactor this a bit so that a References can either be absolute or abstract.

[djmitche]

OK, I'm a good bit happier with that.

[petemoore]

how about:

$schema: "https://taskcluster.net/schemas/common/metadata-metaschema-v1.json#"
metadata:
  - name: "metadata-metaschema"
  - version: 1

;-)

[djmitche]

It seems like having a document be its own metaschema could lead to trouble? What's the benefit here?

[petemoore]

Or maybe this even works(?) I suspect not, I suspect $schema needs to be a fully qualified URI...

$schema: #/
metadata:
  - name: "metadata-metaschema"
  - version: 1

[petemoore]

Just a way of decorating this schema too with metadata, and enabling versioning of it, should we wish to add additional metadata later, for example...

[djmitche]

I don't think anything would read that version, though (and anyway, wouldn't it have to read the version of its metaschema, and just keep going until it looped? And what if the loop was a cycle of more than one metaschema?). Can we just keep this simple?

[imbstack]

This seems to make sense to me. I am in favor of the simplicity approach I think.

[djmitche]

I've released this as v1.0.0. I'm sure there will be some patch releases..