Lambda Geotrellis Tile Server

This repository creates a geotrellis tile server on AWS's API Gateway service, backed by AWS Lambda. The resulting url pattern is:

https://<aws url>/tile/{b}/{p}/{l}/{v}/{z}/{x}/{y}/

Getting data

b, p, and l specify an s3 path to a RasterRDD.

• b is the bucket
• p is the url-encoded prefix
• l is the url-encoded name of the layer

{z}/{x}/{y} is just normal TMS stuff.

Visualizing your layer

The v parameter specifies what type of visualization you'd like. All of the ColorRamps from geotrellis.raster.render.ColorRamps are available with shortened case-insensitive string names. Those names and the corresponding ColorRamps are:

• viridis: Viridis
• magma: Magma
• inferno: Inferno
• plasma: Plasma
• blor: BlueToOrange
• ylor: LightYellowToOrange
• blrd: BlueToRed
• gror: GreenToRedOrange
• sunsetdark: LightToDarkSunset
• greens: LightToDarkGreen
• ylrd: HeatmapYellowToRed
• blylrd: HeatmapBlueToYellowToRedSpectrum
• rdylwt: HeatmapDarkRedToYellowWhite
• prwt: HeatmapLightPurpleToDarkPurpleToWhite
• landuse: ClassificationBoldLandUse
• terrain: ClassificationMutedTerrain

To return an RGB png, pass rgb as the visualization type. No promises about what will happen if you ask for an rgb visualization of a single band tiff.

If you pass in any other string name, you'll get Viridis. You probably wanted Viridis anyway, since it's so pretty.

There's currently no way to specify class breaks, so landuse and terrain currently look pretty dumb.

Deployment

tl;dr: ./scripts/publish

Longer version:

You'll need the following AWS permissions:

• cloudformation:*
• lambda:*
• apigateway:*
• iam:*
• logs:*
• s3:*

A more minimal set of permissions is possible, but I haven't mapped out the extent of permissions requried in each domain. The above will definitely work.

Once that's set up for your user:

• Configure your AWS profile (aws configure --profile <profile name>)
• npm install -g serverless
• ./scripts/publish
• Configure your API gateway endpoint from the AWS console:
  • Set binary media types to image/png in the options for your API
  • Navigate to the GET endpoint and set "Content handling" in its integration response to "Convert to binary (if needed)" for your resource
• Deploy the API using the Actions dropdown