Add in configuration options for connection pool

Closes CrunchyData#4

README.md

@@ -55,12 +55,19 @@ If you want to alter default values other than the database connection, use the
 ```toml
 # Database connection
 DbConnection = "user=you host=localhost dbname=yourdb"
-# Accept connections on this default (default all)
+# Close pooled connections after this interval
+DbPoolMaxConnLifeTime = "1h"
+# Hold no more than this number of connections in the database pool
+DbPoolMaxConns = 4
+# Look to read html templates from this directory
+AssetsPath = "./assets"
+# Accept connections on this subnet (default accepts on all)
 HttpHost = "0.0.0.0"
 # Accept connections on this port
 HttpPort = 7800
 # Advertise URLs relative to this server name
-UrlBase = "http://yourserver.com/"
+# default is to looke this up from incoming request headers
+# UrlBase = "http://yourserver.com/"
 # Resolution to quantize vector tiles to
 DefaultResolution = 4096
 # Padding to add to vector tiles
@@ -199,7 +206,7 @@ Most developers will just use the `tileurl` as is, but it possible to add some p
 * `limit` controls the number of features to write to a tile, the default is 50000.
 * `resolution` controls the resolution of a tile, the default is 4096 units per side for a tile.
 * `buffer` controls the size of the extra data buffer for a tile, the default is 256 units.
-* `attributes` is a comma-separated list of attributes to include in the tile. For wide tables with large numbers of columns, this allows a slimmer tile to be composd.
+* `attributes` is a comma-separated list of attributes to include in the tile. For wide tables with large numbers of columns, this allows a slimmer tile to be composed.
 
 For example:
 
@@ -277,12 +284,11 @@ AS $$
       FROM ne_50m_admin_0_countries t, bounds
       WHERE ST_Intersects(t.geom, ST_Transform(bounds.geom, 4326))
       AND upper(t.name) LIKE (upper(name_prefix) || '%')
-      LIMIT 10000
     )
-    SELECT ST_AsMVT(mvtgeom.*, 'public.countries_name') FROM mvtgeom
+    SELECT ST_AsMVT(mvtgeom, 'public.countries_name') FROM mvtgeom;
 $$
 LANGUAGE 'sql'
-STABLE
+VOLATILE
 PARALLEL SAFE;
 
 COMMENT ON FUNCTION public.countries_name IS 'Filters the countries table by the initial letters of the name using the "name_prefix" parameter.';
@@ -355,7 +361,7 @@ AS $$
       AND ST_DWithin(p.geom, args.click, radius)
       LIMIT 10000
     )
-    SELECT ST_AsMVT(mvtgeom.*, 'public.parcels_in_radius') FROM mvtgeom
+    SELECT ST_AsMVT(mvtgeom, 'public.parcels_in_radius') FROM mvtgeom
 $$
 LANGUAGE 'sql'
 STABLE

db.go

@@ -6,6 +6,7 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+	"time"
 
 	// Database
 	"github.com/jackc/pgx/v4"
@@ -29,6 +30,19 @@ func DbConnect() (*pgxpool.Pool, error) {
 			log.Fatal(err)
 		}
 
+		// Read and parse connection lifetime
+		dbPoolMaxLifeTime, errt := time.ParseDuration(viper.GetString("DbPoolMaxConnLifeTime"))
+		if errt != nil {
+			log.Fatal(errt)
+		}
+		config.MaxConnLifetime = dbPoolMaxLifeTime
+
+		// Read and parse max connections
+		dbPoolMaxConns := viper.GetInt32("DbPoolMaxConns")
+		if dbPoolMaxConns > 0 {
+			config.MaxConns = dbPoolMaxConns
+		}
+
 		// Read current log level and use one less-fine level
 		// below that
 		config.ConnConfig.Logger = logrusadapter.NewLogger(log.New())

layer_proc.go

@@ -183,6 +183,7 @@ func GetFunctionLayers() ([]LayerFunction, error) {
 		AND p.proargnames[1:3] = ARRAY['z'::text, 'x'::text, 'y'::text]
 		AND prorettype = 17
 		AND has_function_privilege(Format('%s.%s(%s)', n.nspname, p.proname, oidvectortypes(proargtypes)), 'execute')
+		ORDER BY 1
 		`
 
 	db, connerr := DbConnect()

layer_table.go

@@ -407,6 +407,7 @@ func GetTableLayers() ([]LayerTable, error) {
 
 	layerSql := `
 	SELECT
+		Format('%s.%s', n.nspname, c.relname) AS id,
 		n.nspname AS schema,
 		c.relname AS table,
 		coalesce(d.description, '') AS description,
@@ -437,6 +438,7 @@ func GetTableLayers() ([]LayerTable, error) {
 		AND has_table_privilege(c.oid, 'select')
 		AND has_schema_privilege(n.oid, 'usage')
 		AND postgis_typmod_srid(a.atttypmod) > 0
+	ORDER BY 1
 	`
 
 	db, connerr := DbConnect()
@@ -454,13 +456,13 @@ func GetTableLayers() ([]LayerTable, error) {
 	for rows.Next() {
 
 		var (
-			schema, table, description, geometry_column string
-			srid                                        int
-			geometry_type, id_column                    string
-			atts                                        pgtype.TextArray
+			id, schema, table, description, geometry_column string
+			srid                                            int
+			geometry_type, id_column                        string
+			atts                                            pgtype.TextArray
 		)
 
-		err := rows.Scan(&schema, &table, &description, &geometry_column,
+		err := rows.Scan(&id, &schema, &table, &description, &geometry_column,
 			&srid, &geometry_type, &id_column, &atts)
 		if err != nil {
 			return nil, err
@@ -492,7 +494,6 @@ func GetTableLayers() ([]LayerTable, error) {
 		}
 
 		// "schema.tablename" is our unique key for table layers
-		id := fmt.Sprintf("%s.%s", schema, table)
 		lyr := LayerTable{
 			Id:             id,
 			Schema:         schema,

main.go

@@ -57,6 +57,9 @@ func main() {
 	viper.SetDefault("DefaultMaxZoom", 22)
 	viper.SetDefault("Debug", false)
 	viper.SetDefault("AssetsPath", "./assets")
+	// 1d, 1h, 1m, 1s, see https://golang.org/pkg/time/#ParseDuration
+	viper.SetDefault("DbPoolMaxConnLifeTime", "1h")
+	viper.SetDefault("DbPoolMaxConns", 4)
 
 	// Read environment configuration first
 	if dbUrl := os.Getenv("DATABASE_URL"); dbUrl != "" {