Add documentation, fix build, upgrade deps, vendor pelias spatial server

.gitignore

@@ -11,4 +11,8 @@ target/
 
 **.geojson
 
-perf.data*
+perf.data*
+
+# Suggested paths for data and index
+data/
+index/

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "spatial"]
+	path = spatial
+	url = https://github.com/ellenhp/spatial

BUILD.md

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+# Airmail build docs
+
+These are extremely barebones but it's what I'm able to throw together with the amount of free time I have available. Contributions and feedback welcome. You will need to modify paths in the commands I've given.
+
+You have two options for indexing:
+1. Build the indexer with cargo.
+2. Build the indexer with Podman.
+
+Option 1 is recommended, but if you have a weird configuration on your system or some of the dependencies are hard to find, you can use podman (or docker) for everything, which should be a little more foolproof.
+
+## Option 1: Install dependencies for a host-side build of the indexer.
+
+Install capnp, clang, pkg-config, zstd's development packages and openssl's development packages.
+
+## Download data
+
+Put data files into ./data
+
+Create ./index with mkdir.
+
+Get OSM file. BBBike and Geofabrik have extracts. Attempt the process with an extract before building the planet.
+
+Download a WhosOnFirst Spatialite database for the country of your selected extract. Use the planet download if you're doing a planet build or your extract covers multiple countries.
+
+## Building the necessary containers
+
+Option 2 only: `podman build -f Dockerfile.build -t airmail_builder`
+
+`podman build -f airmail_indexer/Dockerfile.osmx -t airmail_osmx`
+
+`podman build -f Dockerfile -t airmail_service`
+
+`podman build -f spatial/Dockerfile -t spatial_custom`
+
+## Expanding the OSM data to OSMExpress
+
+Substitute paths for your extract. `podman run --rm -v ./data:/var/osm:Z airmail_osmx expand Seattle.osm.pbf Seattle.osmx`
+
+## Indexing
+
+Option 1: `cargo run --release --bin airmail_import_osm -- --wof-db $PWD/whosonfirst-data-admin-us-latest.spatial.db --index ./index --admin-cache ./admin-cache --osmx $PWD/data/Seattle.osmx --docker-socket /run/user/1000/podman/podman.sock`
+
+OR
+
+Option 2: `chcon -t container_file_t ./data/whosonfirst-data-admin-us-latest.spatial.db; podman run --security-opt label=disable --net=host -v /run/user/1000/podman/podman.sock:/run/podman/podman.sock:z -v ./data:/var/airmail/data:Z -v ./index:/var/airmail/index:Z --rm airmail_build airmail_import_osm --wof-db $PWD/data/whosonfirst-data-admin-us-latest.spatial.db --index /var/airmail/index --admin-cache /var/airmail/data/admin-cache --osmx /var/airmail/data/Seattle.osmx --docker-socket /run/podman/podman.sock --recreate`
+
+## Running the service
+
+`podman run --rm --name airmail-service -p 3000:3000 -v $PWD/index:/var/airmail/index:Z airmail_service --index /var/airmail/index`
+
+