Setting Up MapProxy with Docker and Serving Cached Tiles via Nginx

MapProxy is a powerful open-source proxy for geospatial data that allows for efficient caching and serving of map tiles. Combining MapProxy with Docker and Nginx can provide a scalable and easily manageable solution for serving cached map tiles. This guide will walk you through the process of setting up MapProxy using Docker and configuring Nginx to serve cached tiles.

Prerequisites:

1. Docker installed on your system
2. Basic understanding of Docker
3. Basic understanding of Nginx

If you don't meet this prerequisites yet I recommend to have a look at the following guides first:

• Nginx Beginner’s Guide
• Docker overview
• Install Docker Engine

Step 1: Set Up MapProxy with Docker

Start by creating a Docker Compose file docker-compose.yml with the following content:

yaml
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services:
  mapproxy:
    image: mxdcodes/mapproxy-docker:latest
    container_name: mapproxy
    restart: always
    volumes:
      - /data/containers/mapproxy/config:/mapproxy/config
      - /data/containers/mapproxy/cache_data:/mapproxy/cache_data

Save the file and run:

bash
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docker-compose up -d

This will pull the MapProxy Docker image (https://github.com/dietrichmax/mapproxy-docker) and start the container. MapProxy will be accessible with http://localhost:80 because in the docker image is already Nginx which is used as proxy for MapProxy.

You can store config files in /data/containers/mapproxy/configwhich will be available for MapProxy.

If you want to create a example configuration from Mapproxy you can do it with:

bash
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docker exec -ti mapproxy mapproxy-util create -t base-config /mapproxy/config

Afterwards you should see the following if you open localhost:80

Sorry, somehow the image is not available :(

Step 3: Caching the Tiles with MapProxy

So far you have set up Nginx and MapProxy with Docker and MapProxy will cache by default all served tiles with the default configuration.

Here’s the translation of your text:

Generally, there are two ways to use cache:

• Server Side Caching and
• Client Side Caching

For the server side part I strongly recommend to have a look at the documentation at https://mapproxy.github.io/mapproxy/latest/caches.html. There you will find everything about how you can configure cache with MapProxy.

Additionally you can set Cache-Control and expires headers with the global paramater expires_hours.

expires_hours

The number of hours a Tile is valid. TMS clients like web browsers will cache the tile for this time. Clients will try to refresh the tiles after that time. MapProxy supports the ETag and Last-Modified headers and will respond with the appropriate HTTP ‘304 Not modified’ response if the tile was not changed.

Nginx in the docker image will pass these headers to the client so the client will also know how long a tile should be valid. Thats possible with the following Nginx configuration in case you are curious.

conf
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location / {
        ....
        # Cache
        add_header Cache-Control $upstream_http_cache_control;
        expires $upstream_http_expires;
    }

E.g. I am serving tiles from MapProxy which visualize my locations where I have ever been to. So I don't want to cache the tiles infinite because they change probably every day. However to reduce server load I decided to keep the tiles valid for one hour with the following global configuration:

yaml
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globals:
  # cache options
  tiles:
    expires_hours: 168

If you restart the MapProxy container after setting the configuration and open the URL of your MapProxy service you will find the according headers:

Sorry, somehow the image is not available :(

By following these steps, you've successfully set up MapProxy with Docker and configured Nginx to serve cached map tiles. This scalable solution allows for efficient geospatial data delivery with the added benefit of easy container management. Adjust the configurations based on your specific requirements and integrate this setup into your mapping projects.

If you decide to to take use of MultiMapProxy(scroll down to MultiMapProxy) you can just create more configuration files for MapProxy in /data/containers/mapproxy/config:/mapproxy/config .