OSM Tileserver Ansible playbook

Sample playbook to install and deploy an OSM tile server on a single Debian 11 instance.

The current version uses the following projects :

• oms2pgsql and osm2pgsql-replication
• mod_tile
• openstreetmap-carto

Other versions using imposm, pyosmium or tirex are possible but yet to be implemented. osmosis only solution appears to be superseded by osm2psql-replication.

Using venv to run this playbook

The use of venv is recommended to run the playbook.

Install python3-venv if not already installed:

sudo apt install python3-venv

Execute the following commands to create a virtualenv and install the necessary libs in it :

python3 -m venv venv/ansiblevenv
source venv/ansiblevenv/bin/activate
(ansiblevenv) python3 -m pip install ansible
(ansiblevenv) ansible-galaxy collection install -r requirements.yml

Running this playbook

host_vars/ contains two sample yml files for two types of system configuration (8 CPU/32 GB RAM and 64 CPU/128 GB RAM).

Copy one of the .yml.sample to tileserver.yml and edit values to fit your system:

• Define the connection parameters (IP, username, SSH key, ...) to reach your instance
• Define service_domain, the domain name for the instance (e.g. tiles.domain.com) and layer_name, the name of the default layer (e.g osmcarto)
• Pay specific attention to the PostgreSQL tuning options that must be adjusted to your system sizing (visit https://pgtune.leopard.in.ua/ and https://osm2pgsql.org/doc/manual.html#tuning-the-postgresql-server to determine correct values). Correct values must be defined for import phase and tiles production phase.
• Adjust renderd_num_threads, import_num_threads, osm2pgsql_replication_num_threads, prerender_num_threads and render_old_num_threads to your system. These variables defined the number of threads that will be used or made available by each process.

Note: Some packages are already installed from backports. Check https://blends.debian.org/gis/thermometer/ and edit the playbook to install newest versions if you wish

Run playbook with the following command:

(ansiblevenv) ansible-playbook -i hosts deploy_osm_tileserver.yml

If the playbook succesfully executed, you'll be able to access the demo page for your instance at https://[service_domain]. Map tiles are requested from https://[service_domain]/[layer_domain]/{z}/{x}/{y}.png

By default, the server only accepts requests with referer equals to service_domain. Feel free to adjust the deployed apache configuration to modify this behaviour.

Resources

• Switch2OSM tutorials: https://switch2osm.org/serving-tiles/ and https://github.com/SomeoneElseOSM/mod_tile/tree/switch2osm
• OSM chef cookbooks: https://github.com/openstreetmap/chef
• OSM-FR ansible playboooks: https://github.com/osm-fr/ansible-scripts

TODO

• Improve PostgreSQL tuning (hugepages, tuning options, automatic tuning based on server facts, ...)
• Implement alternative solutions (tirex, etc)
• Improve log management