Running A Serverless Lucene Reverse Geocoder

This is the accompanying GitHub repository for a long blog post at https://spinscale.de/posts/2020-12-09-running-serverless-lucene-reverse-geocoder.html

You can read the motivation behind this repository at the above blog post. You will learn:

• How a reverse geocoder works
• Finding public data sets to implement your reverse geocoder
• Index geo shapes & points with Apache Lucene on Java 11 & Gradle
• Write a CLI application querying Apache Lucene and speed it up using GraalVM
• Deploy the app & index on AWS Lambda using the serverless framework
• Create a small web application using Javalin with built-in authorization
• Deploy a compiled binary on Google Cloud Run enjoying millisecond startups

This README will show you only the most needed commands. Note: This has only been tested with osx and will not work under windows at all, as I have not spent a lot of time fixing all the paths.

Make sure GraalVM is installed, if you have sdkman installed, run

sdk install java 21.0.0.2.r11-grl

Download the geo shape and point data by running

./gradlew :indexer:downloadShapes :indexer:downloadCsvPointFile

Initial index creation is part of the assembly, as well as creating uber jars

./gradlew clean check assemble

You can run the uber jar CLI application now like

java -jar cli/build/libs/cli-all-0.0.1.jar indexer/build/indices 48.13 11.57

Native images are not built by default, but you can run

./gradlew :cli:nativeImage

You can run the CLI application now like

./cli/build/bin/cli-searcher indexer/build/indices 48.1374 11.5755

Creating the docker image can be done via (this will take some time as building in Docker might not be super fast)

./gradlew :dockerBuildImage

You can run that created docker image locally via (note this will build first)

./gradlew :webserver:dockerRunLatest

You should see a rather fast start up like

[main] INFO io.javalin.Javalin - Listening on http://localhost:7000/
[main] INFO io.javalin.Javalin - Javalin started in 4ms \o/

Now you can call one of the following curl call to test if everything has worked and see different response codes in action

# successful search
curl -X POST http://localhost:7000/search \
  --header "Authorization: allowed-token" \
  -d '{"latitude":48.14, "longitude":11.57}'

# error, as token is rejected
curl -X POST http://localhost:7000/search \
  --header "Authorization: rejected-token" \
  -d '{"latitude":48.14, "longitude":11.57}'


# successful health
curl http://localhost:7000/health \
  --header "Authorization: operations-token"

# returning 403
curl http://localhost:7000/health

If you want to deploy to AWS Lambda or Google Cloud Run, please check out the blog post.

Feel free to fork or submit fixes and improvements to this!