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
• Composite Sources
  • Composite Source TileJSON
  • Composite 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
  • Rewriting URLs
  • Caching tiles
• Building from Source
• Debugging
• Development
• Recipes
  • Using with DigitalOcean PostgreSQL
  • Using with Heroku PostgreSQL

Requirements

Martin requires PostGIS >= 2.4.0.

Installation

You can download martin from Github releases page.

Platform	Downloads (latest)
Linux	64-bit
macOS	64-bit
Windows	64-bit

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://postgres@localhost/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://postgres@localhost/db

Martin provides TileJSON endpoint for each geospatial-enabled table in your database.

API

When started, martin will go through all spatial tables and functions with an appropriate signature in the database. These tables and functions will be available as the HTTP endpoints, which you can use to query Mapbox vector tiles.

Method	URL	Description
GET	/index.json	Table Sources List
GET	/{schema_name}.{table_name}.json	Table Source TileJSON
GET	/{schema_name}.{table_name}/{z}/{x}/{y}.pbf	Table Source Tiles
GET	/{schema_name1}.{table_name1},...,{schema_nameN}.{table_nameN}.json	Composite Source TileJSON
GET	/{schema_name1}.{table_name1},...,{schema_nameN}.{table_nameN}/{z}/{x}/{y}.pbf	Composite Source Tiles
GET	/rpc/index.json	Function Sources List
GET	/rpc/{schema_name}.{function_name}.json	Function Source TileJSON
GET	/rpc/{schema_name}.{function_name}/{z}/{x}/{y}.pbf	Function Source Tiles
GET	/healthz	Martin server health check: returns 200 OK

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'
  }
});

You can also combine multiple tables into one source with Composite Sources. Each Table Source in Composite Source can be accessed with its {schema_name}.{table_name} as a source-layer property.

map.addSource('points', {
  type: 'vector',
  url: `http://0.0.0.0:3000/public.points1,public.points2.json`
});

map.addLayer({
  id: 'red_points',
  type: 'circle',
  source: 'points',
  'source-layer': 'public.points1',
  paint: {
    'circle-color': 'red'
  }
});

map.addLayer({
  id: 'blue_points',
  type: 'circle',
  source: 'points',
  'source-layer': 'public.points2',
  paint: {
    'circle-color': 'blue'
  }
});

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.

Note: In case if there are multiple geometry columns in the table, you can specify the geometry column name in the table source name to access particular geometry in vector tile, e.g. schema_name.table_name.geometry_column.

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

In case if you have multiple geometry columns in that table and want to access a particular geometry column in vector tile, you should also specify the geometry column in the table source name

curl localhost:3000/public.points.geom.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

In case if you have multiple geometry columns in that table and want to access a particular geometry column in vector tile, you should also specify the geometry column in the table source name

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

Composite Sources

Composite Sources allows combining multiple Table Sources into one. Composite Source consists of multiple Table Sources separated by comma {schema_name1}.{table_name1},...,{schema_nameN}.{table_nameN}

Each Table Source in Composite Source can be accessed with its {schema_name}.{table_name} as a source-layer property.

Composite Source TileJSON

Composite Source TileJSON endpoint is available at /{schema_name1}.{table_name1},...,{schema_nameN}.{table_nameN}.json.

For example, composite source for points and lines tables in public schema will be available at /public.points,public.lines.json

curl localhost:3000/public.points,public.lines.json

Composite Source Tiles

Composite Source tiles endpoint is available at /{schema_name1}.{table_name1},...,{schema_nameN}.{table_nameN}/{z}/{x}/{y}.pbf

For example, composite source for points and lines tables in public schema will be available at /public.points,public.lines/{z}/{x}/{y}.pbf

curl localhost:3000/public.points,public.lines/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.

Argument	Type	Description
z	integer	Tile zoom parameter
x	integer	Tile x parameter
y	integer	Tile y parameter
query_params	json	Query string parameters

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(ST_CurveToLine(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].
  --default-srid=<n>                If a spatial table has SRID 0, then this default SRID will be used as a fallback.
  --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.
  --ca-root-file=<path>             Loads trusted root certificates from a file. The file should contain a sequence of PEM-formatted CA certificates.
  --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

Environment variable	Example	Description
DATABASE_URL	postgres://postgres@localhost/db	Postgres database connection
WATCH_MODE	true	Scan for new sources on sources list requests
CA_ROOT_FILE	./ca-certificate.crt	Loads trusted root certificates from a file
DEFAULT_SRID	4326	Fallback SRID
DANGER_ACCEPT_INVALID_CERTS	false	Trust invalid certificates

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.

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

# Database connection string
connection_string: 'postgres://postgres@localhost:5432/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

# If a spatial table has SRID 0, then this default SRID will be used as a fallback
default_srid: 4326

# Enable watch mode
watch: false

# 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 (required)
    id: public.table_source

    # Table schema (required)
    schema: public

    # Table name (required)
    table: table_source

    # Geometry SRID (required)
    srid: 4326

    # Geometry column name (required)
    geometry_column: geom

    # Feature id column name
    id_column: ~

    # An integer specifying the minimum zoom level
    minzoom: 0

    # An integer specifying the maximum zoom level. MUST be >= minzoom
    maxzoom: 30

    # The maximum extent of available map tiles. Bounds MUST define an area
    # covered by all zoom levels. The bounds are represented in WGS:84
    # latitude and longitude values, in the order left, bottom, right, top.
    # Values may be integers or floating point numbers.
    bounds: [-180.0, -90.0, 180.0, 90.0]

    # 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 tile properties (required)
    properties:
      gid: int4

# Associative arrays of function sources
function_sources:
  public.function_source:
    # Function source id (required)
    id: public.function_source

    # Schema name (required)
    schema: public

    # Function name (required)
    function: function_source

    # An integer specifying the minimum zoom level
    minzoom: 0

    # An integer specifying the maximum zoom level. MUST be >= minzoom
    maxzoom: 30

    # The maximum extent of available map tiles. Bounds MUST define an area
    # covered by all zoom levels. The bounds are represented in WGS:84
    # latitude and longitude values, in the order left, bottom, right, top.
    # Values may be integers or floating point numbers.
    bounds: [-180.0, -90.0, 180.0, 90.0]

Using with Docker

You can use official Docker image urbica/martin

docker run \
  -p 3000:3000 \
  -e DATABASE_URL=postgres://postgres@localhost/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://postgres@localhost/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://postgres@host.docker.internal/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://postgres@docker.for.win.localhost/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:
      - DATABASE_URL=postgres://postgres:password@db/db
    depends_on:
      - db

  db:
    image: postgis/postgis:14-3.1-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

You can run martin behind Nginx proxy, so you can cache frequently accessed tiles and reduce unnecessary pressure on the database.

version: '3'

services:
  nginx:
    image: nginx:alpine
    restart: unless-stopped
    ports:
      - 80:80
    volumes:
      - ./cache:/var/cache/nginx
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
    depends_on:
      - martin

  martin:
    image: urbica/martin
    restart: unless-stopped
    environment:
      - DATABASE_URL=postgres://postgres:password@db/db
    depends_on:
      - db

  db:
    image: postgis/postgis:14-3.1-alpine
    restart: unless-stopped
    environment:
      - POSTGRES_DB=db
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=password
    volumes:
      - ./pg_data:/var/lib/postgresql/data

You can find an example Nginx configuration file here.

Rewriting URLs

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

location ~ /tiles/(?<fwd_path>.*) {
    proxy_set_header  X-Rewrite-URL $uri;
    proxy_set_header  X-Forwarded-Host $host:$server_port;
    proxy_set_header  X-Forwarded-Proto $scheme;
    proxy_redirect    off;

    proxy_pass        http://martin:3000/$fwd_path$is_args$args;
}

Caching tiles

You can also use Nginx to cache tiles. In the example, the maximum cache size is set to 10GB, and caching time is set to 1 hour for responses with codes 200, 204, and 302 and 1 minute for responses with code 404.

http {
  ...
  proxy_cache_path  /var/cache/nginx/
                    levels=1:2
                    max_size=10g
                    use_temp_path=off
                    keys_zone=tiles_cache:10m;

  server {
    ...
    location ~ /tiles/(?<fwd_path>.*) {
        proxy_set_header        X-Rewrite-URL $uri;
        proxy_set_header        X-Forwarded-Host $host:$server_port;
        proxy_set_header        X-Forwarded-Proto $scheme;
        proxy_redirect          off;

        proxy_cache             tiles_cache;
        proxy_cache_lock        on;
        proxy_cache_revalidate  on;

        # Set caching time for responses
        proxy_cache_valid       200 204 302 1h;
        proxy_cache_valid       404 1m;

        proxy_cache_use_stale   error timeout http_500 http_502 http_503 http_504;
        add_header              X-Cache-Status $upstream_cache_status;

        proxy_pass              http://martin:3000/$fwd_path$is_args$args;
    }
  }
}

You can find an example Nginx configuration file here.

Building from Source

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

git clone git@github.com:urbica/martin.git
cd martin
cargo build --release

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

cd ./target/release/
./martin postgres://postgres@localhost/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 debug logging for all modules:

export RUST_LOG=debug
martin postgres://postgres@localhost/db

While this will only enable verbose logging for the actix_web module and enable debug logging for the martin and tokio_postgres modules:

export RUST_LOG=actix_web=info,martin=debug,tokio_postgres=debug
martin postgres://postgres@localhost/db

Development

Clone project

git clone git@github.com: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://postgres@localhost/db cargo run

Open tests/debug.html for debugging. By default, martin will be available at localhost:3000

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

DATABASE_URL=postgres://postgres@localhost/db cargo test

You can also run benchmarks with

DATABASE_URL=postgres://postgres@localhost/db cargo bench

An HTML report displaying the results of the benchmark will be generated under target/criterion/report/index.html

Recipes

Using with DigitalOcean PostgreSQL

You can use martin with Managed PostgreSQL from DigitalOcean with PostGIS extension

First, you need to download the CA certificate and get your cluster connection string from the dashboard. After that, you can use the connection string and the CA certificate to connect to the database

martin --ca-root-file ./ca-certificate.crt postgres://user:password@host:port/db?sslmode=require

Using with Heroku PostgreSQL

You can use martin with Managed PostgreSQL from Heroku with PostGIS extension

heroku pg:psql -a APP_NAME -c 'create extension postgis'

In order to trust the Heroku certificate, you can disable certificate validation with either DANGER_ACCEPT_INVALID_CERTS environment variable

DATABASE_URL=$(heroku config:get DATABASE_URL -a APP_NAME) DANGER_ACCEPT_INVALID_CERTS=true martin

or --danger-accept-invalid-certs command-line argument

martin --danger-accept-invalid-certs $(heroku config:get DATABASE_URL -a APP_NAME)