About Shigola

Shigola is a vector tile server written in Go. It reads geospatial data from PostGIS and serves it as Mapbox Vector Tiles, over a standards-compliant OGC API - Tiles surface.

Source: MapColonies/shigola.

What it serves

OGC API - Tiles

An OGC API - Tiles surface — landing page, conformance declaration, collections, tilesets, tiles and tiling-scheme definitions. Verified against the official OGC CITE executable test suite.

See OGC API - Tiles.

Multiple tile matrix sets

Shigola carries the OGC register of tile matrix sets as data and serves three of them — WebMercatorQuad, WorldCRS84Quad and WGS1984Quad — selectable per map with tile_matrix_sets.

See Tile matrix sets.

Layered cache

type = "multi" puts an ordered chain of cache backends behind the single [cache] table: reads walk the tiers and promote a hit, writes fan out, and no user response waits on a cache write.

See Layered cache.

What it does not serve

Shigola is a fork of Tegola, but not a superset of it. It removes more than it adds, and what it removes was removed on purpose — this is a server aimed at one job, not a general-purpose Tegola. If you are arriving from tegola.io, these are gone:

Removed	Instead
The built-in map viewer	Nothing. Point your own client at the tile endpoints.
The native /maps/... tile routes	OGC API - Tiles is the only tile surface, and / is its landing page.
The GeoPackage and SAP HANA providers	PostGIS. A config naming gpkg or hana is rejected at startup.
The postgis provider type	mvt_postgis, which encodes the tile in the database with ST_AsMVT. A config naming postgis is rejected at startup with a message saying so.

Everything Shigola kept behaves as Tegola's does unless this site says otherwise, and the official Tegola docs remain the reference for it.

Behaviour worth knowing

Three things commonly surprise people setting Shigola up for the first time:

The service root is the OGC landing page.	/ returns JSON. An unknown path returns 404.
Cache keys begin with the tiling scheme.	The key is {tileMatrixSetId}/{map}/{layer}/{z}/{x}/{y}. Without the scheme, tiles cut in two different schemes would collide at the same z/x/y.
Cache writes do not block the response.	Every cache, chained or not, hands its write to a bounded pool after the response is flushed. See Layered cache.

Credits

• Tegola — Shigola is a fork of go-spatial/tegola, an open source vector tile server created and maintained by the Go Spatial team and documented at tegola.io. Effectively all of this codebase is their work: the providers, the MVT encoder and the tile pipeline all originate there, as did the Go-side geometry processing — clipping, make-valid, simplification — until Shigola moved tile encoding into the database and deleted it. Tegola is MIT licensed, Shigola keeps that licence and retains its copyright notice, and all credit for what Shigola inherited belongs upstream.
• morecantile — Shigola's tms package is a faithful Go port of developmentseed/morecantile 7.0.3, MIT licensed © Development Seed. Its document model, tile algorithms, bundled grid definitions and test suite were all translated, and morecantile's golden values act as the port's correctness oracle. The license is reproduced in the source tree at tms/LICENSE-morecantile.
• OGC API - Tiles is a standard of the Open Geospatial Consortium. Conformance is verified with OGC's own CITE test suite.