Martin

Martin is a PostGIS vector tiles server suitable for large databases. Martin is written in Rust using Actix web framework.

• Requirements
• Installation
• Usage
• API
• Using with Mapbox GL JS
• Using with Leaflet
• Using with deck.gl
• Table Sources
  • Table Sources List
  • Table Source TileJSON
  • Table Source Tiles
• Function Sources
  • Function Sources List
  • Function Source TileJSON
  • Function Source Tiles
• Command-line Interface
• Environment Variables
• Configuration File
• Using with Docker
• Using with Docker Compose
• Using with Nginx
• Building from Source
• Debugging
• Development

Requirements

Martin requires PostGIS >= 2.4.0.

Installation

You can download martin from Github releases page.

If you are using macOS and Homebrew you can install martin using Homebrew tap.

brew tap urbica/tap
brew install martin

You can also use official Docker image

docker run -p 3000:3000 -e DATABASE_URL=postgres://[email protected]/db urbica/martin

Usage

Martin requires a database connection string. It can be passed as a command-line argument or as a DATABASE_URL environment variable.

martin postgres://[email protected]/db

API

Using with Mapbox GL JS

Mapbox GL JS is a JavaScript library for interactive, customizable vector maps on the web. It takes map styles that conform to the Mapbox Style Specification, applies them to vector tiles that conform to the Mapbox Vector Tile Specification, and renders them using WebGL.

You can add a layer to the map and specify martin TileJSON endpoint as a vector source URL. You should also specify a source-layer property. For Table Sources it is {schema_name}.{table_name} by default.

map.addLayer({
  id: 'public.points',
  type: 'circle',
  source: {
    type: 'vector',
    url: 'http://localhost:3000/public.points.json',
  },
  'source-layer': 'public.points',
  paint: {
    'circle-color': 'red',
  },
});

Using with Leaflet

Leaflet is the leading open-source JavaScript library for mobile-friendly interactive maps.

You can add vector tiles using Leaflet.VectorGrid plugin. You must initialize a VectorGrid.Protobuf with a URL template, just like in L.TileLayers. The difference is that you should define the styling for all the features.

L.vectorGrid
  .protobuf('http://localhost:3000/public.points/{z}/{x}/{y}.pbf', {
    vectorTileLayerStyles: {
      'public.points': {
        color: 'red',
        fill: true,
      },
    },
  })
  .addTo(map);

Using with deck.gl

deck.gl is a WebGL-powered framework for visual exploratory data analysis of large datasets.

You can add vector tiles using MVTLayer. MVTLayer data property defines the remote data for the MVT layer. It can be

• String: Either a URL template or a TileJSON URL.
• Array: an array of URL templates. It allows to balance the requests across different tile endpoints. For example, if you define an array with 4 urls and 16 tiles need to be loaded, each endpoint is responsible to server 16/4 tiles.
• JSON: A valid TileJSON object.

const pointsLayer = new MVTLayer({
  data: 'http://localhost:3000/public.points.json', // 'http://localhost:3000/public.table_source/{z}/{x}/{y}.pbf'
  pointRadiusUnits: 'pixels',
  getRadius: 5,
  getFillColor: [230, 0, 0]
});

const deckgl = new DeckGL({
  container: 'map',
  mapStyle: 'https://basemaps.cartocdn.com/gl/dark-matter-gl-style/style.json',
  initialViewState: {
    latitude: 0,
    longitude: 0,
    zoom: 1
  },
  layers: [pointsLayer]
});

Table Sources

Table Source is a database table which can be used to query vector tiles. When started, martin will go through all spatial tables in the database and build a list of table sources. A table should have at least one geometry column with non-zero SRID. All other table columns will be represented as properties of a vector tile feature.

Table Sources List

Table Sources list endpoint is available at /index.json

curl localhost:3000/index.json

Note: if in watch mode, this will rescan database for table sources.

Table Source TileJSON

Table Source TileJSON endpoint is available at /{schema_name}.{table_name}.json.

For example, points table in public schema will be available at /public.points.json

curl localhost:3000/public.points.json

Table Source Tiles

Table Source tiles endpoint is available at /{schema_name}.{table_name}/{z}/{x}/{y}.pbf

For example, points table in public schema will be available at /public.points/{z}/{x}/{y}.pbf

curl localhost:3000/public.points/0/0/0.pbf

Function Sources

Function Source is a database function which can be used to query vector tiles. When started, martin will look for the functions with a suitable signature. A function that takes z integer, x integer, y integer, and query_params json and returns bytea, can be used as a Function Source.

Hint: You may want to use TileBBox function to generate bounding-box geometry of the area covered by a tile.

For example, if you have a table public.table_source in WGS84 (4326 SRID), then you can use this function as a Function Source:

CREATE OR REPLACE FUNCTION public.function_source(z integer, x integer, y integer, query_params json) RETURNS bytea AS $$
DECLARE
  mvt bytea;
BEGIN
  SELECT INTO mvt ST_AsMVT(tile, 'public.function_source', 4096, 'geom') FROM (
    SELECT
      ST_AsMVTGeom(ST_Transform(geom, 3857), TileBBox(z, x, y, 3857), 4096, 64, true) AS geom
    FROM public.table_source
    WHERE geom && TileBBox(z, x, y, 4326)
  ) as tile WHERE geom IS NOT NULL;

  RETURN mvt;
END
$$ LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;

The query_params argument is a JSON representation of the tile request query params. For example, if user requested a tile with urlencoded params:

curl \
  --data-urlencode 'arrayParam=[1, 2, 3]' \
  --data-urlencode 'numberParam=42' \
  --data-urlencode 'stringParam=value' \
  --data-urlencode 'booleanParam=true' \
  --data-urlencode 'objectParam={"answer" : 42}' \
  --get localhost:3000/rpc/public.function_source/0/0/0.pbf

then query_params will be parsed as:

{
  "arrayParam": [1, 2, 3],
  "numberParam": 42,
  "stringParam": "value",
  "booleanParam": true,
  "objectParam": { "answer": 42 }
}

You can access this params using json operators:

...WHERE answer = (query_params->'objectParam'->>'answer')::int;

Function Sources List

Function Sources list endpoint is available at /rpc/index.json

curl localhost:3000/rpc/index.json

Note: if in watch mode, this will rescan database for function sources.

Function Source TileJSON

Function Source TileJSON endpoint is available at /rpc/{schema_name}.{function_name}.json

For example, points function in public schema will be available at /rpc/public.points.json

curl localhost:3000/rpc/public.points.json

Function Source Tiles

Function Source tiles endpoint is available at /rpc/{schema_name}.{function_name}/{z}/{x}/{y}.pbf

For example, points function in public schema will be available at /rpc/public.points/{z}/{x}/{y}.pbf

curl localhost:3000/rpc/public.points/0/0/0.pbf

Command-line Interface

You can configure martin using command-line interface

Usage:
  martin [options] [<connection>]
  martin -h | --help
  martin -v | --version

Options:
  -h --help                         Show this screen.
  -v --version                      Show version.
  --config=<path>                   Path to config file.
  --keep-alive=<n>                  Connection keep alive timeout [default: 75].
  --listen-addresses=<n>            The socket address to bind [default: 0.0.0.0:3000].
  --pool-size=<n>                   Maximum connections pool size [default: 20].
  --watch                           Scan for new sources on sources list requests.
  --workers=<n>                     Number of web server workers.
  --danger-accept-invalid-certs     Trust invalid certificates. This introduces significant vulnerabilities, and should only be used as a last resort.

Environment Variables

You can also configure martin using environment variables

Configuration File

If you don't want to expose all of your tables and functions, you can list your sources in a configuration file. To start martin with a configuration file you need to pass a path to a file with a --config argument.

martin --config config.yaml

You can find an example of a configuration file here.

# Database connection string
connection_string: 'postgres://[email protected]/db'

# Maximum connections pool size [default: 20]
pool_size: 20

# Connection keep alive timeout [default: 75]
keep_alive: 75

# Number of web server workers
worker_processes: 8

# The socket address to bind [default: 0.0.0.0:3000]
listen_addresses: '0.0.0.0:3000'

# Enable watch mode
watch: true

# Trust invalid certificates. This introduces significant vulnerabilities, and should only be used as a last resort.
danger_accept_invalid_certs: false

# associative arrays of table sources
table_sources:
  public.table_source:
    # table source id
    id: public.table_source

    # table schema
    schema: public

    # table name
    table: table_source

    # geometry column name
    geometry_column: geom

    # geometry srid
    srid: 4326

    # tile extent in tile coordinate space
    extent: 4096

    # buffer distance in tile coordinate space to optionally clip geometries
    buffer: 64

    # boolean to control if geometries should be clipped or encoded as is
    clip_geom: true

    # geometry type
    geometry_type: GEOMETRY

    # list of columns, that should be encoded as a tile properties
    properties:
      gid: int4

# associative arrays of function sources
function_sources:
  public.function_source:
    # function source id
    id: public.function_source

    # schema name
    schema: public

    # function name
    function: function_source

Using with Docker

You can use official Docker image urbica/martin

docker run \
  -p 3000:3000 \
  -e DATABASE_URL=postgres://[email protected]/db \
  urbica/martin

If you are running PostgreSQL instance on localhost, you have to change network settings to allow the Docker container to access the localhost network.

For Linux, add the --net=host flag to access the localhost PostgreSQL service.

docker run \
  --net=host \
  -p 3000:3000 \
  -e DATABASE_URL=postgres://[email protected]/db \
  urbica/martin

For macOS, use host.docker.internal as hostname to access the localhost PostgreSQL service.

docker run \
  -p 3000:3000 \
  -e DATABASE_URL=postgres://[email protected]/db \
  urbica/martin

For Windows, use docker.for.win.localhost as hostname to access the localhost PostgreSQL service.

docker run \
  -p 3000:3000 \
  -e DATABASE_URL=postgres://[email protected]/db \
  urbica/martin

Using with Docker Compose

You can use example docker-compose.yml file as a reference

version: '3'

services:
  martin:
    image: urbica/martin
    restart: unless-stopped
    ports:
      - 3000:3000
    environment:
      - WATCH_MODE=true
      - DATABASE_URL=postgres://postgres:[email protected]/db
    depends_on:
      - db

  db:
    image: postgis/postgis:13-3.1-alpine
    restart: unless-stopped
    environment:
      - POSTGRES_DB=db
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=password
    volumes:
      - ./pg_data:/var/lib/postgresql/data

First, you need to start db service

docker-compose up -d db

Then, after db service is ready to accept connections, you can start martin

docker-compose up -d martin

By default, martin will be available at localhost:3000

Using with Nginx

If you are running martin behind nginx proxy, you may want to rewrite request URL, to properly handle tile urls in TileJSON endpoints.

location ~ /tiles/(?<fwd_path>.*) {
    proxy_set_header  X-Rewrite-URL $request_uri;
    proxy_set_header  X-Forwarded-Host $host:$server_port;
    proxy_set_header  X-Forwarded-Proto $scheme; # or $http_x_forwarded_proto
    proxy_pass        http://martin:3000/$fwd_path$is_args$args;
}

Building from Source

You can clone the repository and build martin using cargo package manager.

git clone [email protected]:urbica/martin.git
cd martin
cargo build --release

The binary will be available at ./target/release/martin.

cd ./target/release/
./martin postgres://[email protected]/db

Debugging

Log levels are controlled on a per-module basis, and by default all logging is disabled except for errors. Logging is controlled via the RUST_LOG environment variable. The value of this environment variable is a comma-separated list of logging directives.

This will enable verbose logging for the actix_web module and enable debug logging for the martin and postgres modules:

export RUST_LOG=actix_web=info,martin=debug,postgres=debug
martin postgres://[email protected]/db

Development

Clone project

git clone [email protected]:urbica/martin.git
cd martin

Start db service using docker-compose

docker-compose up -d db

Then, after db service is ready to accept connections, you can start martin with

DATABASE_URL=postgres://[email protected]/db cargo run

By default, martin will be available at localhost:3000

Make your changes, and check if all the tests are running

DATABASE_URL=postgres://[email protected]/db cargo test