I’m glad jsonschema.net was helpful for you, but for future Schemas I highly recommend you to check out Schema Guru (onlline tool). Basically, using it you can without any manual labor generate Schema for any-sized corpus of JSON instances, while not missing any key/property.
As for your second question, Iglu is a schema registry. It defines standards to identify and version Schemas.
We’re providing several implementations for Iglu server and easiest one (and recommended for now) is Static Registry (repo), which is basically just a static web server with predefined folder-structure. You can checkout our Iglu Central (which is example of static repo). So, to use Iglu with Snowplow you’ll need to upload your new custom Schema into corresponding path (like
schemas/com.somecompany/your-new-schema/jsonschema/1-0-0) and use this URI (
iglu:com.somecompany/your-new-schema/jsonschema/1-0-0) to describe your custom contexts and self-describing (unstructured) events.
Hope that is helpful.