get region URL from Proxy variable

We already use the proxy to connect to databases if set: now also
use it to resolve the region endpoint. This will be useful when
running the proxy locally

Author: glommer

internal/cmd/db.go

@@ -182,7 +182,13 @@ func closestLocation(client *turso.Client) (string, error) {
 		return closest, nil
 	}
 
-	closest, err := client.Locations.Closest()
+	settings, err := settings.ReadSettings()
+	if err != nil {
+		return "", fmt.Errorf("could not read settings file to probe for locations: %w", err)
+	}
+
+	regionUrl := settings.GetRegionURL()
+	closest, err := client.Locations.Closest(regionUrl)
 	if err != nil {
 		// We fallback to ams if we are unable to probe the closest location.
 		return "ams", err

internal/settings/settings.go

@@ -2,6 +2,7 @@ package settings
 
 import (
 	"fmt"
+	"net/url"
 	"os"
 	"path"
 	"path/filepath"
@@ -148,6 +149,17 @@ func (s *Settings) GetProxyURL() string {
 	return viper.GetString("proxyURL")
 }
 
+func (s *Settings) GetRegionURL() string {
+	baseURL := s.GetProxyURL()
+	parsedURL, err := url.Parse(baseURL)
+	if err != nil {
+		return "https://region.turso.io"
+	}
+
+	parsedURL.Host = "region." + parsedURL.Host
+	return parsedURL.String()
+}
+
 func (s *Settings) SetAutoupdate(autoupdate string) {
 	config := viper.GetStringMap("config")
 	if config == nil {

internal/turso/locations.go

@@ -52,8 +52,8 @@ type ClosestLocationResponse struct {
 	Server string
 }
 
-func (c *LocationsClient) Closest() (string, error) {
-	r, err := c.client.Get("https://region.turso.io", nil)
+func (c *LocationsClient) Closest(regionUrl string) (string, error) {
+	r, err := c.client.Get(regionUrl, nil)
 	if err != nil {
 		return "", fmt.Errorf("failed to request closest: %s", err)
 	}