In a previous tutorial, I explained the process of building your own OSM tile server on Ubuntu 20.04. This tutorial is going to show you how to set up Nominatim Geocoding server on Ubuntu 20.04. Nominatim provides search functionality for OpenStreetMap, so if a visitor enters an address in a search box, the latitude/longitude location for that address will be returned.

Step 1: Build Nominatim From Source

Install dependency packages to build Nominatim.

sudo apt update

sudo apt install build-essential cmake g   libboost-dev libboost-system-dev libboost-filesystem-dev libexpat1-dev zlib1g-dev libbz2-dev libpq-dev libproj-dev apache2 php php-pgsql libapache2-mod-php php-intl python3-setuptools python3-dev python3-pip python3-psycopg2 python3-tidylib git clang-tidy postgresql-server-dev-12

Create the nominatim user. (No need to create a password for this user.)

sudo useradd -d /srv/nominatim -s /bin/bash -m nominatim

Change to the /srv/nominatim/ directory.

cd /srv/nominatim/

Grant permissions to your own user account.

sudo apt install acl

sudo setfacl -R -m u:username:rwx /srv/nominatim/

Download Nominatim from the official website.

wget https://nominatim.org/release/Nominatim-3.5.1.tar.bz2

Extract the tarball.

tar xvf Nominatim-3.5.1.tar.bz2

Create the build directory.

mkdir build

Change to this directory and configure the build environment.

cd build

cmake /srv/nominatim/Nominatim-3.5.1

Compile the source code.

make

Set Up OSM Nominatim Geocoding Server on Ubuntu 20.04 Nominatim OpenStreetMap ubuntu

Step 2: Configure Nominatim

The default configuration file for Nominatim is /srv/nominatim/build/settings/settings.php. We can create a local.php file and add our modifications there.

sudo nano /srv/nominatim/build/settings/local.php

Add the following lines in the file.

<?php
 @define('CONST_Website_BaseURL', '/nominatim/');
 @define('CONST_Default_Lat', 55.0);
 @define('CONST_Default_Lon', 1.0);
 @define('CONST_Default_Zoom', 6);
 @define('CONST_Map_Tile_URL', 'https://tile.linuxbabe.com/osm/{z}/{x}/{y}.png');

The above configuration defines

  • The path of the Nominatim instance relative to your tile server.
  • Default latitude, longitude, and zoom level.
  • URL of your OSM tile server. By default, Nominatim uses the public openstreetmap.org tile server. Here I use my own tile server.

You can also take a look at the /srv/nominatim/build/settings/settings.php file and add your own customizations if the need arises. For example, if you are going to import a large dataset (Europe, North America, planet, etc.), it’s a good practice to enable flat node storage of node locations, so node coordinates will be stored in a simple file instead of the database, saving you import time and disk storage.

@define('CONST_Osm2pgsql_Flatnode_File', '/srv/nominatim/flatnode.file');

Save and close the file.

Step 3: Import OSM Database

Download Wikipedia importance dump file, which will improve the quality of the Nomiatim search results.

cd /srv/nominatim/Nominatim-3.5.1/data

wget https://www.nominatim.org/data/wikimedia-importance.sql.gz

Download US and UK postcodes data.

wget https://www.nominatim.org/data/us_postcode_data.sql.gz

wget https://www.nominatim.org/data/gb_postcode_data.sql.gz

Then you need to download an OSM file and import it to PostgreSQL. You can go to http://download.geofabrik.de to download the extract you need. You can also use the PBF file during the tile server setup process.

Create the www-data user in PostgreSQL, so the web server will have read-only access to the database.

sudo -u postgres createuser www-data

Grant permission to the postgres user.

sudo setfacl -R -m u:postgres:rwx /srv/nominatim/

Switch to the postgres user.

sudo -u postgres -i

And run the following command to import OSM extracts to PostgreSQL.

cd /srv/nominatim/build/

/srv/nominatim/build/utils/setup.php --osm-file /home/osm/great-britain-latest.osm.pbf --all 2>&1 | tee setup.log

After importing the database, the indexing process will begin.

Set Up OSM Nominatim Geocoding Server on Ubuntu 20.04 Nominatim OpenStreetMap ubuntu

Once it’s finished, run the following command to verify.

/srv/nominatim/build/utils/check_import_finished.php

Set Up OSM Nominatim Geocoding Server on Ubuntu 20.04 Nominatim OpenStreetMap ubuntu

Exit out of the postgres user.

exit

Step 4: Set Up Apache

Edit the tile server configuration file.

sudo nano /etc/apache2/sites-enabled/tileserver_site-le-ssl.conf

Add the following lines between the VirtualHost tags.

  Options FollowSymLinks MultiViews
  AddType text/html   .php
  DirectoryIndex search.php
  Require all granted


alias /nominatim /srv/nominatim/build/website

Save and close the file. Then reload Apache.

sudo systemctl reload apache2

Now visit https://tile.yourdomain.com/nominatim. You will see your Nomiatim instance.

Set Up OSM Nominatim Geocoding Server on Ubuntu 20.04 Nominatim OpenStreetMap ubuntu

The CSS file is located at /srv/nominatim/build/website/css/search.css, if you want to customize the looking.

Update Nominatim Database

To keep the Nominatim database up to date, we need to install Pyosmium. It’s available from the default software repository, but it’s recommended to install the latest version using pip3.

sudo pip3 install osmium

This will install a binary /usr/local/bin/pyosmium-get-changes. Edit Nominatim configuration file.

sudo nano /srv/nominatim/build/settings/local.php

Add the following line to specify the location of pyosmium-get-changes.

@define('CONST_Pyosmium_Binary', '/usr/local/bin/pyosmium-get-changes');

Next, we need to tell Nominatim where to download updates. By default, it’s configured to download updates from https://planet.openstreetmap.org/replication/minute. If you downloaded the OSM PBF file from geofabrik.de, then it’s better to also download updates from there.

To find the update URL for your own map, go to https://download.geofabrik.de/ and locate your region. Then find the URL for the .osc.gz file.

Set Up OSM Nominatim Geocoding Server on Ubuntu 20.04 Nominatim OpenStreetMap ubuntu

This URL is the update URL.

Set Up OSM Nominatim Geocoding Server on Ubuntu 20.04 Nominatim OpenStreetMap ubuntu

Add the following line in /srv/nominatim/build/settings/local.php file. You need to use your own update URL.

// base URL of the replication service
@define('CONST_Replication_Url', 'http://download.geofabrik.de/europe/great-britain-updates');
// How often upstream publishes diffs
@define('CONST_Replication_Update_Interval', '86400');
// How long to sleep if no update found yet
@define('CONST_Replication_Recheck_Interval', '900');

Save and close the file. Grant permissions to the postgres user.

sudo setfacl -R -m "u:postgres:rwx" /srv/nominatim/build/

Then swith to the postgres user.

sudo -u postgres -i

Initialize the update process.

/srv/nominatim/build/utils/update.php --init-updates

Update Nominatim database.

/srv/nominatim/build/utils/update.php --import-osmosis-all

Set Up Cron Job For Automatic Update

Edit root user’s Crontab file.

sudo crontab -e

Add the following line in this file.

@daily sudo -u postgres /srv/nominatim/build/utils/update.php --import-osmosis-all

Save and close the file.

Wrapping Up

I hope this tutorial helped you set up Nominatim geocoding server on Ubuntu 20.04. As always, if you found this post useful, then subscribe to our free newsletter to get more tips and tricks. Take care 🙂

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