How to install PostGIS on Mountain Lion

I recently needed to run some geographical analysis and PostGIS seemed like a perfect fit for this. So off I went to install it, here's how.

Assumptions

Step 0: Install PostgreSQL

If you don't have PostgreSQL already installed, it should be a simple matter of getting it via MacPorts:

$ port install postgresql91 postgresql91-server

Also, I am sure there are tons of tutorials out there to help with this, so I won't cover that here.

Install PostGIS 1.5

Simple enough:

$ port install postgis

Note that there is a PostGIS 2.0 out there, but it requires PostgreSQL 9.2 and I wasn't ready for upgrading just yet.

Setup a geospatially enabled database

This part had me a bit stumped, and digging up the right file paths for this to work took a while:

$ createdb geo
$ createlang plpgsql geo
$ psql -d geo -f /opt/local/share/postgresql91/contrib/postgis-1.5/postgis.sql
$ psql -d geo -f /opt/local/share/postgresql91/contrib/postgis-1.5/spatial_ref_sys.sql

If you figure you need to routinely setup new databases like this, it might be an idea to create a database template to use in the future.

Test that it worked

The following should output a ton (400+) of functions:

$ psql geo -c "\df" | grep st_

If it did, you're good to go. If it didn't, good luck.