Make current test.zr3 available via HTTP

[manzt]

I have translated the current zarrita implementation into javascript here: https://github.com/manzt/zarrita.js

It would be great to have a live example test.zr3 somewhere so that I we can test/verify compatibility with other implementations. I think I remember there being some discussion in zarr-python about this, but I'm not sure if it was related to v3.

Not a major issue, but just wanted to make those interested aware.

[joshmoore]

cc: @Carreau @constantinpape

I'm happy to host on S3 if it will be useful. Another option would be to start working it into https://github.com/constantinpape/zarr_implementations

[alimanfoo]

Hi @manzt, that's fantastic news. Yes it would be great to build some datasets that we can use to verify compatibility. For the time being, if it's useful, the test.zr3 is up on GCS at this path and should be public: gs://zarr-demo/v3/test.zr3 ... happy to copy that to S3 or anywhere else if it would be useful.

[manzt]

Thanks @alimanfoo! Is it possible to set Access-Control-Allow-Origin: * for the bucket? https://cloud.google.com/storage/docs/cross-origin

This will enable CORS so that a webpage can make requests to the endpoint. If you open your browser console this currently errors:

>> await fetch('https://storage.googleapis.com/zarr-demo/v3/test.zr3/zarr.json')
// Content Security Policy: The page’s settings blocked the loading of a resource at https://storage.googleapis.com/zarr-demo/v3/test.zr3/zarr.json (“connect-src”).

For reference the HTTP endpoint works when using curl and not making cross-origin requests:

$ curl https://storage.googleapis.com/zarr-demo/v3/test.zr3/zarr.json | jq
{
  "zarr_format": "https://purl.org/zarr/spec/protocol/core/3.0",
  "metadata_encoding": "https://purl.org/zarr/spec/protocol/core/3.0",
  "metadata_key_suffix": ".json",
  "extensions": []
}

[joshmoore]

@manzt: a copy is available at https://s3.embassy.ebi.ac.uk/idr/share/zarr-demo/v3/test.zr3/

[manzt]

Thanks @joshmoore. Here is a live JS notebook if folks are interested: https://observablehq.com/d/7156b4838eed011d

(I'd like to set up some type of like "can-i-use" table for different types of arrays, since all can't be supported in the browser. For example, JavaScript doesn't have built in support for float16 or boolean arrays - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Typed_arrays)

[alimanfoo]

Thanks @alimanfoo! Is it possible to set Access-Control-Allow-Origin: * for the bucket?

I think I've done that, can you try again?

I did gsutil cors set cors.json gs://zarr-demo/ with this as cors.json:

    [
      {
        "origin": ["*"],
        "responseHeader": ["Content-Type"],
        "method": ["GET", "HEAD"],
        "maxAgeSeconds": 3600
      }
    ]

[manzt]

Working for me -- thanks! I added a drop down to toggle the endpoint.

Update: 11:41AM EST 2020-11-25, GCS link not working for me.