igluctl: add validate subcommand

[chuwy]

Just a wrapper around Iglu Scala Client. Users often use Snowplow Mini only in order to validate their self-describing entities (events and contexts), though they are independent from enriched event and can be validated via CLI.

igluctl --resolver iglu_resolver.json --data context.json

• Resolver can be default to iglucentral-only
• Without --data it should be able to receive data from stdin
• context.json can contain NDJSON

Probably same functionality for Iglu Server would be nice, where resolver defaults only to current Registry.

[alexanderdean]

By a context do you just mean a self-decribing JSON? "Context" is Snowplow language, not Iglu...

[chuwy]

Yes, I meant any self-describing JSON.

[alexanderdean]

Cool, make sure that help text doesn't refer to a context...

[chuwy]

Server ticket: #326

[miike]

Big fan of this idea as it makes it'd make it a lot easier to have some of this run as part of continuous integration pipelines.

[chuwy]

CI/CD is a great point, @miike. We've just scheduled next (minor) release of Iglu, but I'm very keen to add this ticket into next one.

[aldemirenes]

Migrated to snowplow/igluctl#19