vapor-clock

Cloud-powered offline tasks.

Tasks

This is a task definition that uses the reproject option to reproject an SRTM cell to Web Mercator (EPSG:3857). input is passed directly to gdalwarp; you'll almost always want to use /vsicurl to point at remote sources. In this case, /vsizip is also used, as the source raster is contained in a zip file. Output is written to the URL provided in output (only S3 buckets are supported, and data is written with the public-read ACL).

{
  name: "reproject SRTM to 3857",
  input: "/vsizip/vsicurl/http://data.stamen.com.s3.amazonaws.com/srtm/source/srtm_01_07.zip/srtm_01_07.tif",
  output: "s3://data.stamen.com/srtm/3857/srtm_01_07.tiff",
  operations: [
    {
      type: "reproject",
      options: {
        targetSRS: "EPSG:3857"
      }
    }
  ]
}

Operations

hillshade

Generates hillshades using gdaldem.

reproject

Reprojects GDAL-readable rasters to targetSRS.

Options

• targetSRS - Target SRS. Equivalent to gdalwarp's -t_srs option. Required.

resample

Resamples rasters in 3857 to a given targetExtent and targetResolution.

Options

• targetExtent - Target Extent, an array of four values in the EPSG:3857 projection: xmin ymin xmax ymax. Equivalent to gdalwarp's -te option. Required.
• targetResolution - Target Resolution, an array of two values in EPSG:3857 units: xres yres. Equivalent to gdalwarp's -tr option. Required.

Environment Variables

• AWS_ACCESS_KEY_ID - Optional if instance roles are used.
• AWS_SECRET_ACCESS_KEY - Optional if instance roles are used.
• SENTRY_DSN - Sentry DSN for error reporting. Optional.
• SQS_QUEUE_NAME - Queue name. This is also used as the prefix (with _failed) for the dead letter queue. Required.

Required Permissions

The AWS credentials must have sufficient access to create / modify / read / write SQS queues named SQS_QUEUE_NAME and ${SQS_QUEUE_NAME}_failed. You should also grant access to any S3 buckets you wish to write to.

Miscellany

To create a VRT for S3-hosted SRTM data, do something like this:

(for f in $(< srtm.list); do echo /vsicurl/http://data.stamen.com.s3.amazonaws.com/srtm/3857/${f%%.zip}.tiff; done) | xargs gdalbuildvrt srtm.vrt

You can then refer to an S3-hosted version of that VRT:

gdalwarp -te -124.7494 45.5437 -116.9161 49.0049 \
  /vsicurl/http://data.stamen.com.s3.amazonaws.com/srtm/SRTM-4326.vrt \
  SRTM-washington.tiff

docker run -p 1080:1080 -v $(pwd)/conf:/etc/nginx/sites-enabled dockerfile/nginx