See an example at whatsmydistrict.org.

• Ruby 1.9.3
• postgresql -- brew install postgres
• postgis -- brew install postgis

1. bundle

2. puma to start the server at localhost:9292.

3. For a new postgresql install in OS X:

    mkdir -p ~/Library/LaunchAgents
    cp /usr/local/Cellar/postgresql/9.2.1/homebrew.mxcl.postgresql.plist ~/Library/LaunchAgents/
    launchctl load -w ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist
    initdb /usr/local/var/postgres -E utf8
    pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start
   

   See also Postgres.app.

4. Create the database: createdb -p 5432 -h localhost blake

5. Add necessary postgis functions to the database: psql -p 5432 -h localhost -d blake -f /usr/local/share/postgis/postgis.sql and psql -p 5432 -h localhost -d blake -f /usr/local/share/postgis/spatial_ref_sys.sql -- thanks to PostGres - PostGIS on OS X Lion.

1. Download the new shape file from data.lexingtonky.gov -- for example, under Community, Board of Elections - Voting Precincts.

2. Run shp2pgsql -c -D -s 4269 -I shapefile.shp tablename > filename.sql. For example:

    $ shp2pgsql -c -D -s 4269 -I VotingPrecinct.shp voting > VotingPrecinct.sql
    Shapefile type: Polygon
    Postgis type: MULTIPOLYGON[2]
   

3. In psql, drop the table you will be updating.

4. Run psql -d database -f file.sql, for example psql -p 5432 -h localhost -d blake -f VotingPrecinct.sql.