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A template for a black base layer about Southern California. Designed for overlaying bright data visualizations. Created with open data. Configured for TileMill and Mapnik. Ready to deploy to Amazon S3 using Fabric, invar and boto.

Read more in this introductory post.

Layers

• Roads by OpenStreetMap using a state extract published by Geofabrik
• Places by the U.S. Census via census.ire.org
• Neighborhoods and regions by The Times' Mapping LA project

Installation

The first thing to do is install TileMill, the open-source map design studio by MapBox.

Some of the tricks in this repo require you to install TileMill using its source code rather than MapBox's prepackaged releases. Instructions on how to do that can be found here.

Next clone this repository, or a fork of it, to your computer. I recommend doing this inside of a virtualenv.

# Create the virtualenv
$ virtualenv osm-silent-la
# Jump into it
$ cd osm-silent-la
# Turn it on
$ . bin/activate
# Pull down this repository into a subdirectory
$ git clone https://github.com/datadesk/osm-silent-la.git repo

Create a symbolic link installing Quite LA inside Mapbox's project directory. You'll need to substitute your path below.

$ ln -s /path/to/this/repo/silent-la /path/to/Documents/MapBox/project/

Install PostgreSQL with the PostGIS extensions that allow the database to do geometry. If you haven't done this before, I would recommend follow the instructions included with GeoDjango. Just focus on the PostGIS part and you will be in good hands.

Next you need to download OpenStreetMap data covering the area you're going to map. I'm sticking with California, but you could use this system to map any of the 50 states that make up America.

I've condensed all the steps into a Fabric function in this repository's fabfile. Besides Fabric, it requires the OpenStreetMap utility for loading data into PostgresSQL. On Ubuntu, you can install them like so.

$ sudo apt-get install fabric
$ sudo apt-get install osm2pgsql

Once that's out of the way, it might be this easy.

$ fab update_osm
# Or if you want another state
$ fab update_osm:state=iowa

Though if you're not on Ubuntu you might have to tweak each step a little. Crack open the fabfile and you'll figure it out pretty quick. It's a few basic steps.

# Download and unzip the OSM extract for your state. I use Geofabrik as a source because they update frequently.
$ curl -O http://download.geofabrik.de/openstreetmap/north-america/us/california.osm.bz2
$ bunzip2 ./california.osm.bz2
# Create a new PostgreSQL database to store the data. Substitute your postgres user and state.
$ sudo -u postgres createdb -U postgres -T template_postgis osm_california
# Use osm2pgsql to load the OpenStreetMap data into the database.
# The location of the default.style file can be different depending on the platform.
# This is where it shows up in the latest Ubuntu distro, but you might need to dig up its path on your system.
$ osm2pgsql -U postgres -d osm_california -S /usr/share/osm2pgsql/default.style california.osm
# Delete that osm file now that you don't need it anymore.
$ rm california.osm

Finally, you have to configure the Tilemill configuration file to work with your PostgreSQL database. You can do this by filling out the options at the top of configure.py in this directory and then running it.

$ python configure.py

Deployment

There are additional steps you need to take before you are able to deploy tiles created with this template to Amazon S3 for public use.

First, set an environment variable that leads to the directory where you installed TileMill.

# Consider adding this to your .bashrc or .bash_profile but can also just run it from the shell
$ export TILEMILL=/path/to/repo/for/tilemill

Use our fabric function to create a new set of tiles using TileMill.

$ fab build_tiles

Log into your Amazon account at aws.amazon.com and create one or more S3 buckets to hold your tiles.

Edit the tile_bucket environment variable in fabfile.py to point to your bucket name.

env.tile_bucket = 'yourbucket'

Install the Python dependencies necessary to interact with S3.

# Jump into your virtualenv and turn it on
$ . bin/activate
# Install the Python requirements with pip
$ pip install -r repo/requirements.txt

Store your Amazon access key and secret key in the config file for boto, the Python library for accessing S3.

# That is found right here
$ vim ~/.boto

You'll need to provide them as boto expects.

[Credentials]
aws_access_key_id = your_key
aws_secret_access_key = your_secret_key

Now all that's left is to upload the files in bulk using invar's handy S3 uploader.

$ fab deploy_tiles

Credits

This application was created by Ben Welsh at the Los Angeles Times Data Desk. The cosmetic design was inspired by Radical Cartography and the Chicago Tribune News Applications team. The technical design borrows heavily from MapBox's osm-bright.