openstreetmap-carto developer setup

osm_carto_dev_setup.md

openstreetmap-carto Developer Setup

• data: PostgreSQL + PostGIS, osm2pgsql for importing into the database; and OSM data extract
• code: openstreetmap-carto (+ Git, Python)
• editing software: Kosmtik (+ Node.js)

Preparation

• install PostgreSQL
• install Git
• install Node.js
• install Python if needed (already there on MacOS X and Linux)
• install osm2pgsql
• get a OSM data extract: e.g. Geofabrik or Mapzen Metro-Extracts

openstreetmap-carto

• create a folder for openstreetmap-carto and change into the directory on the command line (or Git-Bash)
• Click "Clone or download" at the GitHub-Repository and select "Use HTTPS"
• copy the URL
• execute git clone <copied URL> . (code will be checked out in current directory)
• execute ./get-shapefiles.sh or ./get-shapefiles.py (whatever exists)

Database

• create a database (name e.g. osm)
• activate PostGIS: CREATE EXTENSION postgis;
• opt. activate HStore: CREATE EXTENSION hstore;
• import data (Linux):

sudo -u postgres osm2pgsql --create --slim --cache CACHE --number-processes NUM --hstore --style path/to/openstreetmap-carto/openstreetmap-carto.style --multi-geometry --database osm --username postgres path/to/extract.pbf

CACHE = size of RAM - memory in use - X (do not choose a size too big as swapping might become necessary then [slow])

NUM = number of CPU cores

Importing can take quite some time depending on the size of the data extract!

Install Kosmtik

• Click "Clone or download" at the GitHub-Repository and select "Download ZIP" (or use the method like for osm-carto above)
• extract the ZIP-file in a directory
• execute npm install in this directory (needs Node.js)

Configure and start Kosmtik

• create a local config file, e.g. osm.localconfig:

exports.LocalConfig = function (localizer, project) {
localizer.where('center').then([13.0463, 47.7978, 15]); // Salzburg
localizer.where('Layer').if({'Datasource.type': 'postgis'}).then({
	"Datasource.dbname": "osm",
	"Datasource.password": "postgres",
	"Datasource.user": "postgres",
	"Datasource.host": "localhost"
});
// You can also do it in pure JS
project.mml.bounds = [1, 2, 3, 4];
};

• start Kosmtik:

node index.js serve --localconfig path/to/osm.localconfig path/to/openstreetmap-carto/project.yaml

edit osm-carto

• use your own text editor e.g. Atom, gedit, TextWrangler, Notepad++
• change the *.mss files
• view the changes in Kosmtik
• if you change the layer definitions in project.yaml you have to execute ./yaml2mml.py