tessera

tessera is a tilelive-based tile server.

Using the power of the tilelive ecosystem, it is capable of serving and rendering tiles from many sources.

Installation

npm install -g tessera
npm install -g <tilelive modules...>

How to Use

tessera does not install tilelive providers itself; it is up to you to (globally) install any modules that you wish to use (along with dependencies present in your configuration; e.g. a TM2 style that loads data tiles from an HTTP source).

Modules listed in tilelive-modules will be auto-detected and loaded if they have been installed. For other modules, you will need to --require them explicitly.

To serve up an MBTiles archive using node-mbtiles:

npm install -g mbtiles
tessera mbtiles://./whatever.mbtiles

Note: If you want to be able to preview vector tiles (MVT/PBF), you need these 2 modules:

npm install -g tilelive-vector tilelive-xray

To serve up a TileMill (or Carto) project using tilelive-carto:

tessera carto+file://./project.mml

To serve up a TM2 style using tilelive-tmstyle:

tessera tmstyle://./

Note: non-mapbox: sources may need to have their protocols changed; tessera requires that styles using HTTP-accessible data have tilejson+http: as their protocol where TM2 expects http:. See mojodna/tilelive-http#2 for more information.

To serve up a TM2 data source (it will use data.yml as the source of truth) using tilelive-tmsource:

tessera tmsource://./

To serve up a bare Mapnik stylesheet using tilelive-mapnik:

tessera mapnik://./stylesheet.xml

To serve up files from a filesystem using tilelive-file:

tessera file://./tiles

To proxy HTTP-accessible tiles using tilelive-http:

tessera http://tile.stamen.com/toner/{z}/{x}/{y}.png

To proxy Mapbox-hosted tiles using tilelive-mapbox:

tessera mapbox:///mapbox.mapbox-streets-v4

To proxy tiles with available TileJSON using node-tilejson:

tessera tilejson+http://a.tiles.mapbox.com/v3/mapbox.mapbox-streets-v4.json

A TileJSON endpoint is available at localhost:8080/index.json with various bits of metadata about the tiles being served.

Configuration

Tessera has command-line options:

Usage: node tessera.js [uri] [options]

uri     tilelive URI to serve

Options:
   -C SIZE, --cache-size SIZE          Set the cache size (in MB)  [10]
   -c CONFIG, --config CONFIG          Provide a configuration file or directory
   -p PORT, --port PORT                Set the HTTP Port  [8080]
   -b HOST, --bind HOST                Set interface to listen on [0.0.0.0]
   -m, --multiprocess                  Start multiple processes  [false]
   -P, --processes                     Number of processes to start  [8]
   -r MODULE, --require MODULE         Require a specific tilelive module
   -S SIZE, --source-cache-size SIZE   Set the source cache size (in # of sources)  [10]
   -s SOCKET, --socket SOCKET          Listen on unix socket
   -v, --version                       Show version info

A tilelive URI or configuration file is required.

Commonly used options can be set using the TESSERA_OPTS environment variable.

This is what a configuration file looks like:

{
  "/": {
    "source": "mbtiles:///Users/seth/archive.mbtiles",
    "cors": false,
    "timing": false
  },
  "/a": {
    "source": "mbtiles:///Users/seth/archive.mbtiles",
    "headers": {
      "Cache-Control": "public,max-age={{#tileJSON}}86400{{/tileJSON}}{{#tile}}3600{{/tile}}",
      "Surrogate-Control": "max-age=86400",
      "Surrogate-Keys": "{{#tile}}z{{zoom}} x{{x}} y{{y}}{{/tile}}"
    }
  },
  "/b": "mbtiles:///Users/seth/archive.mbtiles"
}

Header values are treated as Mustache (technically Handlebars) templates, which allow them to vary by request. The following variables are available to header templates:

• tile.retina - for retina (@2x) requests
• tile.zoom - zoom (for tile requests)
• tile.x - row (for tile requests)
• tile.y - column (for tile requests)
• tile.format - requested format
• tileJSON - for TileJSON requests
• 200 - HTTP 200
• 404 - HTTP 404
• invalidFormat - the requested format did not match what the tilelive source provides
• invalidZoom - the requested zoom is outside the available range
• invalidCoordinates - the requested coordinates are outside the available bounds

CORS and X-Response-Time can be disabled per-style:

{
  "cors": false,
  "timing": false
}

(Note that enabling for / will propagate to all subdirectories, as they act as middleware.)

Custom tile paths may be set per-style:

{
  "tilePath": "/{z}/{x}/{y}-debug.{format}"
}

The default tile path is:

{
  "tilePath": "/{z}/{x}/{y}.{format}"
}

(Note: the final . will be expanded to transparently support retina requests (effectively /{z}/{x}/{y}@2x.{format}).)

If --config is set to a directory, all JSON files in it will be concatenated together to form a single configuration. In the case of repeated options or paths, the last one will win (where files are loaded in alphabetical order).

For sources that render rasters from vector tiles at and have a max zoom level that is higher than the max zoom level of the vector tiles it can be helpful to have additional variables available for headers that represent the vector tile that a raster was rendered from. This can be enabled with an additional source option in the configuration file:

{
  "sourceMaxZoom": 14
}

This will make three additional values available for header templates:

• tile.sourceZoom
• tile.sourceX
• tile.sourceY

For example: if sourceMaxZoom is set to 14, a request for tile 16/100/100 will set the following variables:

• tile.sourceZoom = 14
• tile.sourceX = 25
• tile.sourceY = 25

Multiprocess mode

By default, tessera runs in a single process (modules, e.g. Mapnik, may use multiple threads). For sources that are CPU intensive to render, or when running on servers with large numbers of CPU cores there can be significant performance improvements from running in multiprocess mode. When multiprocess mode is enabled with the --multiprocess option multiple processes will be started, with each process running a single thread, enabling many requests to be served at once. The number of processes to be started defaults to the number of CPU cores on the host, but can be configured with the --processes option.

Environment Variables

• PORT - Port to bind to. Defaults to 8080.
• HOST - Interface to listen on. Defaults to 0.0.0.0 (all).
• CACHE_SIZE - Cache size (in MB) for tilelive-cache. Defaults to 10MB.
• SOCKET - Unix socket to bind to. Optional.
• SOURCE_CACHE_SIZE - Number of sources to cache (for tilelive-cache). Defaults to 6. NOTE: implicit retina versions count as an extra source.
• TESSERA_OPTS - Additional command-line arguments.