Okay, so I’ve been messing around with this “Valhalla” thing for mapping and routing, and I wanted to share how I got it working, ’cause it took me a bit to figure it out. It’s all about getting distances and stuff, you know, like how far is it from point A to point B?
Getting Started
First, I had to get Valhalla up and running. I’m using Docker, ’cause it’s just easier. I pulled down a pre-built image somebody made, I did not build it from scratch or make my own.
Feeding it Data
Next up, I needed some map data. Valhalla uses this OpenStreetMap stuff, which is basically like a free, open-source map of the world. Downloaded a chunk of data for my area. It’s just a file, you know, nothing too scary.
Setting up the Config
Now, Valhalla needs a config file. It’s a bit of a pain, all this JSON formatting, but basically, you tell it where your map data is, what kind of routing you want (car, bike, walking), and some other settings. I just copied one I found online and tweaked it a little.
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make a configuration file
The `*` configuration file is the “boss” for Valhalla.
Running the Thing
With the Docker image and the config file ready, I fired up the Valhalla server. It took a few minutes to load all the map data into memory, but once it was up, I could start sending it requests.
Making Requests
This is where it gets interesting. You send Valhalla a request with some coordinates, and it spits back the distance and the route. The requests are also in this JSON format, so, more curly braces and stuff. For, example, to create the matrix, I used the ‘sources’ and ‘targets’.
Figuring Out the Output
The output from Valhalla is also JSON. I used the matrix results. It gives you a bunch of numbers, distances, times, that kind of thing. I had to poke around a bit to understand what each number meant, but eventually, I figured it out. It’s basically a table of distances between all the points I gave it.
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Check the yardage
The distance from A to B.
So, yeah, that’s how I got Valhalla to give me yardages. It’s not super simple, but once you get the hang of it, it’s pretty powerful. Now I can figure out how far things are, and I can use that in my project. I am super excited with the results.
