Simple HTTPS server used for serving OME-Zarr data

Difference to the standard Simple HTTP Python server:

• Added permissive CORS settings
• Added support for HTTP range requests, to address issues with rendering of sharded OME-Zarr data. See: https://forum.image.sc/t/tools-for-converting-to-ome-zarr-v0-5/114369/31

Invocation:

python server.py

No additional dependencies required.

Serving on port 5500 by default. A custom port can be specified by invoking:

python server.py [port number]

Alternatives

• ome_zarr_py implements a CLI tool for serving and viewing Zarr files (Invocation: ome_zarr view [OMEZarrFile]) - based on Python HTTPSimpleServer as above. This may be more convenient to use in some circumstances, as it opens the image through the ngff-validator frontend, from where multiple viewers (Vizarr, Vol-E, Neuroglancer, napari) are available at a mouseclick to display a Zarr image.

• Ruby's standard library implements a simple https server. Configuring header injection (e.g., CORS) may be done with a simple script:

ruby -rwebrick -e '
  root = Dir.pwd
  server = WEBrick::HTTPServer.new(
    Port: 8000,
    DocumentRoot: root,
    AccessLog: [],               # silence WEBrick’s default log (optional)
    Logger: WEBrick::Log.new("/dev/null") # silence startup banner (optional)
  )
  # Insert a generic CORS header on every response
  server.mount_proc "/" do |req, res|
    res["Access-Control-Allow-Origin"] = "*"
    res["Access-Control-Allow-Methods"] = "GET, POST, PUT, DELETE, OPTIONS"
    res["Access-Control-Allow-Headers"] = "Origin, X-Requested-With, Content-Type, Accept"
    # Let WEBrick handle the actual file serving
    WEBrick::HTTPServlet::FileHandler.new(server, root).service(req, res)
  end
  trap("INT") { server.shutdown }
  server.start
'