TileJSON 3.0 support with layer fields discovery and cached /capabilities responses

atlas/map.go

@@ -64,8 +64,6 @@ type Map struct {
 
 	mvtProviderName string
 	mvtProvider     provider.MVTTiler
-
-	observer observability.Interface
 }
 
 // HasMVTProvider indicates if map is a mvt provider based map
@@ -194,13 +192,11 @@ func (m Map) encodeMVTProviderTile(ctx context.Context, tile slippy.Tile, params
 		}
 	}
 	return m.mvtProvider.MVTForLayers(ctx, ptile, params, layers)
-
 }
 
 // encodeMVTTile will encode the given tile into mvt format
 // TODO (arolek): support for max zoom
 func (m Map) encodeMVTTile(ctx context.Context, tile slippy.Tile, params provider.Params) ([]byte, error) {
-
 	// tile container
 	var mvtTile mvt.Tile
 	// wait group for concurrent layer fetching
@@ -214,7 +210,6 @@ func (m Map) encodeMVTTile(ctx context.Context, tile slippy.Tile, params provide
 
 	// iterate our layers
 	for i, layer := range m.Layers {
-
 		// go routine for fetching the layer concurrently
 		go func(i int, l Layer) {
 			mvtLayer := mvt.Layer{

cmd/internal/register/maps.go

@@ -1,13 +1,15 @@
 package register
 
 import (
+	"fmt"
 	"html"
 	"regexp"
 	"strings"
 
 	"github.com/go-spatial/geom"
 	"github.com/go-spatial/tegola/atlas"
 	"github.com/go-spatial/tegola/config"
+	"github.com/go-spatial/tegola/mapbox/tilejson"
 	"github.com/go-spatial/tegola/provider"
 )
 
@@ -32,7 +34,6 @@ func webMercatorMapFromConfigMap(cfg provider.Map) (newMap atlas.Map) {
 		newMap.TileBuffer = uint64(*cfg.TileBuffer)
 	}
 	return newMap
-
 }
 
 func layerInfosFindByName(infos []provider.LayerInfo, name string) provider.LayerInfo {
@@ -48,10 +49,8 @@ func layerInfosFindByName(infos []provider.LayerInfo, name string) provider.Laye
 }
 
 func atlasLayerFromConfigLayer(cfg *provider.MapLayer, mapName string, layerProvider provider.Layerer) (layer atlas.Layer, err error) {
-	var (
-		// providerLayer is primary used for error reporting.
-		providerLayer = string(cfg.ProviderLayer)
-	)
+	// providerLayer is primary used for error reporting.
+	providerLayer := string(cfg.ProviderLayer)
 	// read the provider's layer names
 	// don't care about the error.
 	providerName, layerName, _ := cfg.ProviderLayerName()
@@ -123,12 +122,9 @@ func selectProvider(name string, mapName string, newMap *atlas.Map, providers ma
 	return nil, ErrProviderNotFound{name}
 }
 
-// Maps registers maps with with atlas
+// Maps registers maps with with atlas.
 func Maps(a *atlas.Atlas, maps []provider.Map, providers map[string]provider.TilerUnion) error {
-
-	var (
-		layerer provider.Layerer
-	)
+	var layerer provider.Layerer
 
 	// iterate our maps
 	for _, m := range maps {
@@ -144,6 +140,17 @@ func Maps(a *atlas.Atlas, maps []provider.Map, providers map[string]provider.Til
 				}
 			}
 
+			// if our map requests TileJSON v3 specifically
+			// we have to validate that the provider supports it.
+			// if m.TileJSONVersion is not being provided tegola determines
+			// the TileJSON version for the user.
+			if m.TileJSONVersion == tilejson.Version3 {
+				p := providers[providerName]
+				if ok, err := p.IsTileJSONV3Compatible(); !ok {
+					return fmt.Errorf("%w: %s", err, providerName)
+				}
+			}
+
 			// find our layer provider
 			layerer, err = selectProvider(providerName, string(m.Name), &newMap, providers)
 			if err != nil {

cmd/internal/register/maps_test.go

@@ -8,6 +8,7 @@ import (
 	"github.com/go-spatial/tegola/cmd/internal/register"
 	"github.com/go-spatial/tegola/dict"
 	"github.com/go-spatial/tegola/internal/env"
+	"github.com/go-spatial/tegola/mapbox/tilejson"
 	"github.com/go-spatial/tegola/provider"
 )
 
@@ -39,7 +40,6 @@ func TestMaps(t *testing.T) {
 			if !errors.Is(err, tc.expectedErr) {
 				t.Errorf("invalid error, expected %v got %v", tc.expectedErr, err)
 			}
-			return
 		}
 	}
 
@@ -125,6 +125,26 @@ func TestMaps(t *testing.T) {
 				},
 			},
 		},
+		"fails when map requires TileJSON v3 but provider does not implement": {
+			maps: []provider.Map{
+				{
+					Name:            "test",
+					TileJSONVersion: tilejson.Version3,
+					Layers: []provider.MapLayer{
+						{
+							ProviderLayer: "foo.bar",
+						},
+					},
+				},
+			},
+			providers: []dict.Dict{
+				{
+					"name": "foo",
+					"type": "debug",
+				},
+			},
+			expectedErr: provider.ErrNotTileJSONV3Compatible,
+		},
 		"success": {
 			maps: []provider.Map{},
 			providers: []dict.Dict{

config/config.go

@@ -6,13 +6,15 @@ import (
 	"io"
 	"net/http"
 	"os"
+	"slices"
 	"strings"
 	"time"
 
 	"github.com/BurntSushi/toml"
 	"github.com/go-spatial/tegola"
 	"github.com/go-spatial/tegola/internal/env"
 	"github.com/go-spatial/tegola/internal/log"
+	"github.com/go-spatial/tegola/mapbox/tilejson"
 	"github.com/go-spatial/tegola/provider"
 )
 
@@ -157,7 +159,6 @@ func ValidateAndRegisterParams(mapName string, params []provider.QueryParameter)
 
 // Validate checks the config for issues
 func (c *Config) Validate() error {
-
 	var knownTypes []string
 	drivers := make(map[string]int)
 	for _, name := range provider.Drivers(provider.TypeStd) {
@@ -200,7 +201,6 @@ func (c *Config) Validate() error {
 	// maps with configured parameters for logging
 	mapsWithCustomParams := []string{}
 	for mapKey, m := range c.Maps {
-
 		// validate any declared query parameters
 		if err := ValidateAndRegisterParams(string(m.Name), m.Parameters); err != nil {
 			return err
@@ -214,6 +214,14 @@ func (c *Config) Validate() error {
 			mapLayers[string(m.Name)] = map[string]provider.MapLayer{}
 		}
 
+		if m.TileJSONVersion != "" &&
+			!slices.Contains(
+				[]string{tilejson.Version3, tilejson.Version2},
+				m.TileJSONVersion,
+			) {
+			return ErrUnknownTileJSONVersion
+		}
+
 		// Set current provider to empty, for MVT providers
 		// we can only have the same provider for all layers.
 		// This allow us to track what the first found provider
@@ -387,7 +395,7 @@ func Load(location string) (conf Config, err error) {
 		log.Infof("loading remote config (%v)", location)
 
 		// setup http client with a timeout
-		var httpClient = &http.Client{
+		httpClient := &http.Client{
 			Timeout: time.Second * 10,
 		}
 

config/config_test.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/go-spatial/tegola/config"
 	"github.com/go-spatial/tegola/internal/env"
+	"github.com/go-spatial/tegola/mapbox/tilejson"
 	"github.com/go-spatial/tegola/provider"
 	_ "github.com/go-spatial/tegola/provider/debug"
 	_ "github.com/go-spatial/tegola/provider/postgis"
@@ -61,7 +62,6 @@ func TestParse(t *testing.T) {
 
 	fn := func(tc tcase) func(*testing.T) {
 		return func(t *testing.T) {
-
 			f, err := os.Open(tc.configPath)
 			if err != nil {
 				t.Fatalf("unexpected error: %s", err)
@@ -388,7 +388,6 @@ func TestParse(t *testing.T) {
 }
 
 func TestValidateMutateZoom(t *testing.T) {
-
 	type tcase struct {
 		config          *config.Config
 		expectedMinZoom int
@@ -511,7 +510,6 @@ func TestValidateMutateZoom(t *testing.T) {
 	for name, tc := range tests {
 		t.Run(name, fn(tc))
 	}
-
 }
 
 func TestValidate(t *testing.T) {
@@ -1318,12 +1316,56 @@ func TestValidate(t *testing.T) {
 				},
 			},
 		},
+		"invalid tilejson version": {
+			expectedErr: config.ErrUnknownTileJSONVersion,
+			config: config.Config{
+				Providers: []env.Dict{
+					{
+						"name": "some_provider",
+						"type": "mvt_test",
+					},
+				},
+				Maps: []provider.Map{
+					{
+						Name:            "some_map",
+						Attribution:     "Test Attribution",
+						TileJSONVersion: "foobar",
+						Layers: []provider.MapLayer{
+							{
+								ProviderLayer: "some_provider.some_layer",
+							},
+						},
+					},
+				},
+			},
+		},
+		"valid tilejson version": {
+			config: config.Config{
+				Providers: []env.Dict{
+					{
+						"name": "some_provider",
+						"type": "mvt_test",
+					},
+				},
+				Maps: []provider.Map{
+					{
+						Name:            "some_map",
+						Attribution:     "Test Attribution",
+						TileJSONVersion: tilejson.Version3,
+						Layers: []provider.MapLayer{
+							{
+								ProviderLayer: "some_provider.some_layer",
+							},
+						},
+					},
+				},
+			},
+		},
 	}
 
 	for name, tc := range tests {
 		t.Run(name, fn(tc))
 	}
-
 }
 
 func TestConfigureTileBuffers(t *testing.T) {

config/errors.go

@@ -1,12 +1,16 @@
 package config
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
+	"github.com/go-spatial/tegola/mapbox/tilejson"
 	"github.com/go-spatial/tegola/provider"
 )
 
+var ErrUnknownTileJSONVersion = errors.New("tilejson_version invalid. can either be " + tilejson.Version2 + " or " + tilejson.Version3)
+
 type ErrMapNotFound struct {
 	MapName string
 }

mapbox/tilejson/tilejson.go

@@ -2,7 +2,10 @@
 // https://github.com/mapbox/tilejson-spec
 package tilejson
 
-const Version = "2.1.0"
+const (
+	Version2 = "2.0.0"
+	Version3 = "3.0.0"
+)
 
 type GeomType string
 
@@ -135,4 +138,7 @@ type VectorLayer struct {
 	MaxZoom uint `json:"maxzoom"`
 	// Tegola supports individual layer tiles.
 	Tiles []string `json:"tiles"`
+	// REQUIRED in TileJSON 3.0.0. An object whose keys and values are the names
+	// and descriptions of attributes available in this layer.
+	Fields map[string]any `json:"fields,omitempty"`
 }

provider/errors.go

@@ -9,9 +9,11 @@ import (
 
 var (
 	// ErrCanceled is returned when cancel was requested
-	ErrCanceled    = fmt.Errorf("provider: %v", context.Canceled)
-	ErrUnsupported = errors.New("provider: unsupported")
-	ErrNilInitFunc = errors.New("init function can not be nil")
+	ErrCanceled                = fmt.Errorf("provider: %v", context.Canceled)
+	ErrUnsupported             = errors.New("provider: unsupported")
+	ErrNilInitFunc             = errors.New("init function can not be nil")
+	ErrNotTileJSONV3Compatible = errors.New("provider is not TileJSON version 3 compatible")
+	ErrNoProvider              = errors.New("no provider provided")
 )
 
 type ErrUnableToConvertFeatureID struct {

provider/map.go

@@ -4,11 +4,12 @@ import "github.com/go-spatial/tegola/internal/env"
 
 // A Map represents a map in the Tegola Config file.
 type Map struct {
-	Name        env.String       `toml:"name"`
-	Attribution env.String       `toml:"attribution"`
-	Bounds      []env.Float      `toml:"bounds"`
-	Center      [3]env.Float     `toml:"center"`
-	Layers      []MapLayer       `toml:"layers"`
-	Parameters  []QueryParameter `toml:"params"`
-	TileBuffer  *env.Int         `toml:"tile_buffer"`
+	Name            env.String       `toml:"name"`
+	Attribution     env.String       `toml:"attribution"`
+	Bounds          []env.Float      `toml:"bounds"`
+	Center          [3]env.Float     `toml:"center"`
+	Layers          []MapLayer       `toml:"layers"`
+	Parameters      []QueryParameter `toml:"params"`
+	TileBuffer      *env.Int         `toml:"tile_buffer"`
+	TileJSONVersion string           `toml:"tilejson_version"`
 }