mbtileserver

A simple Go-based server for map tiles stored in mbtiles format.

It currently provides support for png, jpg, and pbf (vector tile) tilesets according to version 1.0 of the mbtiles specification. Tiles are served following the XYZ tile scheme, based on the Web Mercator coordinate reference system.

At the moment, UTF8 Grids are not yet supported.

In addition to tile-level access, it provides:

TileJSON 2.1.0 endpoint for each tileset, with full metadata from the mbtiles file.
a preview map for exploring each tileset.
a minimal ArcGIS tile map service API (work in progress)

It uses golang/groupcache to provide caching of tiles for even faster performance.

We have been able to host a bunch of tilesets on an AWS t2.nano virtual machine without any issues.

Goals

Provide a web tile API for map tiles stored in mbtiles format
Be fast
Run on small resource cloud hosted machines (limited memory & CPU)
Be easy to install and operate

Installation

Currently, this project is not go get-able because static assets and templates are not downloaded via go get. We're working toward this.

In the meantime, clone this repository using your git tool of choice.

go get the dependencies:

On Windows, it is necessary to install gcc in order to compile mattn/go-sqlite3.
MinGW or TDM-GCC should work fine.

Then build it:

go build .

This will create an executable called mbtileserver.

Usage

From within the repository root:

$  ./mbtileserver --help
Serve tiles from mbtiles files

Usage:
  mbtileserver [flags]

Flags:
      --cachesize int   Size of cache in MB. (default 250)
  -c, --cert string     X.509 TLS certificate filename.  If present, will be used to enable SSL on the server.
  -d, --dir string      Directory containing mbtiles files. (default "./tilesets")
      --dsn string      Sentry DSN
  -k, --key string      TLS private key
  -p, --port int        Server port. (default 8000)
  -v, --verbose         Verbose logging

So hosting tiles is as easy as putting your mbtiles files in the tilesets directory and starting the server. Woo hoo!

When you want to remove, modify, or add new tilesets, simply restart the server process.

If a valid Sentry DSN is provided, warnings, errors, fatal errors, and panics will be reported to Sentry.

Specifications

expects mbtiles files to follow version 1.0 of the mbtiles specification. Version 1.1 is preferred.
implements TileJSON 2.1.0

Creating Tiles

You can create mbtiles files using a variety of tools. We have created tiles for use with mbtileserver using:

TileMill (image tiles)
tippecanoe (vector tiles)
tpkutils (image tiles from ArcGIS tile packages)

We are working on some new tools to create UTF8 Grids for use here.

Examples

TileJSON API for each tileset: http://localhost/services/states_outline

returns something like this;

{
  "bounds": [
    -179.23108,
    -14.601813,
    179.85968,
    71.441055
  ],
  "center": [
    0.314297,
    28.419622,
    1
  ],
  "credits": "US Census Bureau",
  "description": "States",
  "format": "png",
  "id": "states_outline",
  "legend": "[{\"elements\": [{\"label\": \"\", \"imageData\": \"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAGFJREFUOI3tlDEOgEAIBClI5kF+w0fxwXvQdjZywcZEtDI31YaQgWrdPsYzAPFGJCmmEAhJGzCash0wSVE/HHnlKcDMfrPXYgmXcAl/JswK6lCrz89BdGVm1+qrH0bbWDgA3WwmgzD8ueEAAAAASUVORK5CYII=\"}], \"name\": \"tl_2015_us_state\"}]",
  "map": "http://localhost/services/states_outline/map",
  "maxzoom": 4,
  "minzoom": 0,
  "name": "states_outline",
  "scheme": "xyz",
  "tags": "states",
  "tilejson": "2.1.0",
  "tiles": [
    "http://localhost/services/states_outline/tiles/{z}/{x}/{y}.png"
  ],
  "type": "overlay",
  "version": "1.0.0"
}

It provides all elements of the metadata table in the mbtiles file.

XYZ tile endpoint for individual tiles: http://localhost/services/states_outline/tiles/{z}/{x}/{y}.png

The map endpoint: http://localhost/services/states_outline/map

provides an interactive Leaflet map for image tiles, including a few helpful plugins like a legend (if compatible legend elements found in TileJSON) and a transparency slider. Vector tiles are previewed using Mapbox GL.

ArcGIS API

We are currently working on providing a minimal ArcGIS tiled map service API for tiles stored in an mbtiles file. This should be sufficient for use with online platforms such as Data Basin. Because the ArcGIS API relies on a number of properties that are not commonly available within an mbtiles file, so certain aspects are stubbed out with minimal information.

This API is not intended for use with more full-featured ArcGIS applications such as ArcGIS Desktop.

Live Examples

These are hosted on a free dyno by Heroku (thanks Heroku!), so there might be a small delay when you first access these.

List of services
TileJSON for a PNG based tileset generated using TileMill.
Map Preview for a map preview of the above.
ArcGIS Map Service

Roadmap

See the issues tagged to the 0.5 version for our near term features and improvements.

In short, we are planning to:

make this project go get-able
refactor the internals to better separate mbtiles interface from API logic
add tests and benchmarks
get things production ready

Development

Development of the templates and static assets likely requires using node and npm. Install these tools in the normal way.

From the templates/static folder, run

$npm install

to pull in the static dependencies. These are referenced in the package.json file.

Then to build the minified version, run:

$gulp build

Modifying the go files requires re-running go build.

buma / mbtileserver