Pick closest Xirsys server based on users geo location

.editorconfig

@@ -0,0 +1,12 @@
+root = true
+
+[*]
+insert_final_newline = true
+
+[{*.kt,*.kts}]
+ktlint_code_style = intellij_idea
+
+#  Disable wildcard imports entirely
+ij_kotlin_name_count_to_use_star_import = 2147483647
+ij_kotlin_name_count_to_use_star_import_for_members = 2147483647
+ij_kotlin_packages_to_use_import_on_demand = unset

README.md

@@ -2,9 +2,9 @@
 
 The FAF ICE server broker that returns access to TURN and STUN servers both static (self-hosted coturn) and dynamically (Xirsys). 
 
-This project uses Quarkus, the Supersonic Subatomic Java Framework.
+The available environment variables for configuration can be found in `src/main/resources/application.yaml`. Variables are declared like `${ENV_VARIABLE_NAME:fallback-value}`.
 
-If you want to learn more about Quarkus, please visit its website: https://quarkus.io/ .
+This application makes use of the [GeoLite2](https://dev.maxmind.com/geoip/geolite2-free-geolocation-data) database to search for the closest Xirsys server according to the users ip address. The file must be present on startup or all requests will fall back to Frankfurt, Germany.
 
 ## Running the application in dev mode
 

build.gradle.kts

@@ -41,6 +41,7 @@ dependencies {
     implementation("io.quarkus:quarkus-resteasy-reactive")
     implementation("io.quarkus:quarkus-flyway")
     implementation("org.flywaydb:flyway-mysql")
+    implementation("com.maxmind.geoip2:geoip2:4.1.0")
     testImplementation("io.quarkus:quarkus-junit5")
     testImplementation("io.rest-assured:rest-assured")
 }

gradle.properties

@@ -2,4 +2,4 @@ quarkusPluginId=io.quarkus
 quarkusPluginVersion=3.12.0
 quarkusPlatformGroupId=io.quarkus.platform
 quarkusPlatformArtifactId=quarkus-bom
-quarkusPlatformVersion=3.12.0
+quarkusPlatformVersion=3.12.0

src/main/kotlin/com/faforever/icebreaker/config/FafProperties.kt

@@ -11,6 +11,12 @@ interface FafProperties {
      */
     fun environment(): String
 
+    /**
+     * Define the header, where to pick the real ip address from. For regular reverse proxies such as nginx or Traefik,
+     * this is X-Real-Ip. However, in certain scenarios such as Cloudflare proxy different headers might be required.
+     */
+    fun realIpHeader(): String
+
     fun tokenLifetimeSeconds(): Long
 
     fun maxSessionLifeTimeHours(): Long

src/main/kotlin/com/faforever/icebreaker/service/xirsys/XirsysApiAdapter.kt

@@ -1,14 +1,18 @@
 package com.faforever.icebreaker.service.xirsys
 
 import com.faforever.icebreaker.config.FafProperties
+import com.faforever.icebreaker.service.xirsys.geolocation.RegionSelectorService
 import com.fasterxml.jackson.databind.ObjectMapper
 import com.fasterxml.jackson.module.kotlin.readValue
+import io.vertx.core.http.HttpServerRequest
 import jakarta.inject.Singleton
+import jakarta.ws.rs.core.Context
 import org.eclipse.microprofile.faulttolerance.Retry
 import org.eclipse.microprofile.rest.client.RestClientBuilder
 import org.slf4j.Logger
 import org.slf4j.LoggerFactory
 import java.io.IOException
+import java.net.InetAddress
 import java.net.URI
 
 private val LOG: Logger = LoggerFactory.getLogger(XirsysApiAdapter::class.java)
@@ -20,7 +24,9 @@ private val LOG: Logger = LoggerFactory.getLogger(XirsysApiAdapter::class.java)
 class XirsysApiAdapter(
     private val fafProperties: FafProperties,
     private val xirsysProperties: XirsysProperties,
+    private val regionSelectorService: RegionSelectorService,
     private val objectMapper: ObjectMapper,
+    @Context private val httpRequest: HttpServerRequest,
 ) {
     private val xirsysApiClient: XirsysApiClient =
         RestClientBuilder
@@ -34,13 +40,12 @@ class XirsysApiAdapter(
             ).build(XirsysApiClient::class.java)
 
     @Retry
-    fun listChannel(): List<String> =
-        parseAndUnwrap {
-            xirsysApiClient.listChannel(
-                namespace = xirsysProperties.channelNamespace(),
-                environment = fafProperties.environment(),
-            )
-        }
+    fun listChannel(): List<String> = parseAndUnwrap {
+        xirsysApiClient.listChannel(
+            namespace = xirsysProperties.channelNamespace(),
+            environment = fafProperties.environment(),
+        )
+    }
 
     @Retry
     fun createChannel(channelName: String) {
@@ -79,13 +84,26 @@ class XirsysApiAdapter(
     fun requestIceServers(
         channelName: String,
         turnRequest: TurnRequest = TurnRequest(),
-    ): TurnResponse =
-        parseAndUnwrap {
-            xirsysApiClient.requestIceServers(
-                namespace = xirsysProperties.channelNamespace(),
-                environment = fafProperties.environment(),
-                channelName = channelName,
-                turnRequest = turnRequest,
+    ): TurnResponse = parseAndUnwrap<TurnResponse> {
+        xirsysApiClient.requestIceServers(
+            namespace = xirsysProperties.channelNamespace(),
+            environment = fafProperties.environment(),
+            channelName = channelName,
+            turnRequest = turnRequest,
+        )
+    }.withUserLocationServers()
+
+    private fun TurnResponse.withUserLocationServers(): TurnResponse =
+        regionSelectorService.getClosestRegion(httpRequest.getIp()).let { region ->
+            copy(
+                iceServers = iceServers.copy(
+                    urls = iceServers.urls.map {
+                        it.replace(
+                            regex = Regex("(.+:)([\\w-]+.xirsys.com)(.*)"),
+                            replacement = "$1${region.domain}$3",
+                        )
+                    },
+                ),
             )
         }
 
@@ -107,4 +125,7 @@ class XirsysApiAdapter(
             throw XirsysUnspecifiedApiException(errorResponse = response, cause = e)
         }
     }
+
+    private fun HttpServerRequest.getIp() =
+        InetAddress.getByName(getHeader(fafProperties.realIpHeader()) ?: remoteAddress().host())
 }

src/main/kotlin/com/faforever/icebreaker/service/xirsys/XirsysProperties.kt

@@ -15,4 +15,6 @@ interface XirsysProperties {
     fun secret(): String
 
     fun channelNamespace(): String
+
+    fun geoIpPath(): String
 }

src/main/kotlin/com/faforever/icebreaker/service/xirsys/XirsysSessionHandler.kt

@@ -34,27 +34,22 @@ class XirsysSessionHandler(
 
     override fun getIceServers() = listOf(Server(id = SERVER_NAME, region = "Global"))
 
-    override fun getIceServersSession(sessionId: String): List<Session.Server> =
-        xirsysApiAdapter
-            .requestIceServers(
-                channelName = sessionId,
-                turnRequest = TurnRequest(expire = fafProperties.tokenLifetimeSeconds()),
-            ).iceServers
-            .let {
-                listOf(
-                    Session.Server(
-                        id = SERVER_NAME,
-                        username = it.username,
-                        credential = it.credential,
-                        urls =
-                            it.urls
-                                .map { url ->
-                                    // A sample response looks like "stun:fr-turn1.xirsys.com"
-                                    // The java URI class fails to read host and port due to the missing // after the :
-                                    // Thus we "normalize" the uri, even though it is technically valid
-                                    url.replaceFirst(":", "://")
-                                }.filter { url -> turnEnabled || !url.startsWith("turn") },
-                    ),
-                )
-            }
+    override fun getIceServersSession(sessionId: String): List<Session.Server> = xirsysApiAdapter.requestIceServers(
+        channelName = sessionId,
+        turnRequest = TurnRequest(expire = fafProperties.tokenLifetimeSeconds()),
+    ).iceServers.let {
+        listOf(
+            Session.Server(
+                id = SERVER_NAME,
+                username = it.username,
+                credential = it.credential,
+                urls = it.urls.map { url ->
+                    // A sample response looks like "stun:fr-turn1.xirsys.com"
+                    // The java URI class fails to read host and port due to the missing // after the :
+                    // Thus we "normalize" the uri, even though it is technically valid
+                    url.replaceFirst(":", "://")
+                }.filter { url -> turnEnabled || !url.startsWith("turn") },
+            ),
+        )
+    }
 }

src/main/kotlin/com/faforever/icebreaker/service/xirsys/geolocation/GeoLocation.kt

@@ -0,0 +1,24 @@
+package com.faforever.icebreaker.service.xirsys.geolocation
+
+import kotlin.math.atan2
+import kotlin.math.cos
+import kotlin.math.sin
+import kotlin.math.sqrt
+
+internal interface GeoLocation {
+    val latitude: Double
+    val longitude: Double
+
+    // Haversine formula to calculate distance between two points in kilometers
+    fun distanceTo(other: GeoLocation): Double {
+        val r = 6371 // Radius of the earth in kilometers
+        val latDistance = Math.toRadians(other.latitude - this.latitude)
+        val lonDistance = Math.toRadians(other.longitude - this.longitude)
+        val a =
+            sin(latDistance / 2) * sin(latDistance / 2) +
+                cos(Math.toRadians(this.latitude)) * cos(Math.toRadians(other.latitude)) *
+                sin(lonDistance / 2) * sin(lonDistance / 2)
+        val c = 2 * atan2(sqrt(a), sqrt(1 - a))
+        return r * c // Distance in kilometers
+    }
+}

src/main/kotlin/com/faforever/icebreaker/service/xirsys/geolocation/RegionSelectorService.kt

@@ -0,0 +1,43 @@
+package com.faforever.icebreaker.service.xirsys.geolocation
+
+import com.faforever.icebreaker.service.xirsys.XirsysProperties
+import com.maxmind.geoip2.DatabaseReader
+import com.maxmind.geoip2.model.CityResponse
+import jakarta.inject.Singleton
+import org.slf4j.LoggerFactory
+import java.net.InetAddress
+import java.nio.file.Files
+import java.nio.file.Paths
+
+private val LOG = LoggerFactory.getLogger(RegionSelectorService::class.java)
+
+@Singleton
+class RegionSelectorService(
+    xirsysProperties: XirsysProperties,
+) {
+    private val geoIpDatabasePath = Paths.get(xirsysProperties.geoIpPath())
+
+    private val geoLocationReader: DatabaseReader? by lazy {
+        if (!Files.exists(geoIpDatabasePath)) {
+            LOG.warn("No geo database found at $geoIpDatabasePath! Will use fallback region ${XirsysRegion.fallbackRegion.name}")
+            null
+        } else {
+            DatabaseReader.Builder(geoIpDatabasePath.toFile()).build()
+        }
+    }
+
+    private data class UserLocation(
+        override val latitude: Double,
+        override val longitude: Double,
+    ) : GeoLocation
+
+    fun getClosestRegion(ipAddress: InetAddress): XirsysRegion =
+        geoLocationReader
+            ?.tryCity(ipAddress)
+            ?.map(CityResponse::getLocation)
+            ?.map { getClosestRegion(UserLocation(latitude = it.latitude, longitude = it.longitude)) }
+            ?.orElse(null)
+            ?: XirsysRegion.fallbackRegion
+
+    private fun getClosestRegion(userLocation: UserLocation): XirsysRegion = XirsysRegion.allRegions.minBy { it.distanceTo(userLocation) }
+}

src/main/kotlin/com/faforever/icebreaker/service/xirsys/geolocation/XirsysRegion.kt

@@ -0,0 +1,30 @@
+package com.faforever.icebreaker.service.xirsys.geolocation
+
+data class XirsysRegion(
+    val domain: String,
+    val name: String,
+    val city: String,
+    override val latitude: Double,
+    override val longitude: Double,
+) : GeoLocation {
+    companion object {
+        // listed on https://docs.xirsys.com/?pg=api-intro (manually enriched with geo coordinates)
+        val allRegions =
+            listOf(
+                XirsysRegion("ws.xirsys.com", "US West", "San Jose, CA", 37.33939000, -121.89496000),
+                XirsysRegion("us.xirsys.com", "US East", "Washington, DC", 38.89511000, -77.03637000),
+                XirsysRegion("es.xirsys.com", "Europe", "Amsterdam", 52.37403000, 4.88969000),
+                XirsysRegion("bs.xirsys.com", "India", "Bangalore", 12.97194000, 77.59369000),
+                XirsysRegion("tk.xirsys.com", "Japan", "Tokyo", 35.67619190, 139.65031060),
+                XirsysRegion("hk.xirsys.com", "China", "Hong Kong", 22.396428, 114.109497),
+                XirsysRegion("ss.xirsys.com", "Asia", "Singapore", 1.352083, 103.819836),
+                XirsysRegion("ms.xirsys.com", "Australia", "Sydney", -33.86785, 151.20732),
+                XirsysRegion("sp.xirsys.com", "Brazil", "São Paulo", -23.5475, -46.63611),
+                XirsysRegion("to.xirsys.com", "Canada East", "Toronto", 43.70011, -79.4163),
+                XirsysRegion("jb.xirsys.com", "South Africa", "Johannesburg", -26.20227, 28.04363),
+                XirsysRegion("fr.xirsys.com", "Germany", "Frankfurt", 50.11552, 8.68417),
+            )
+
+        val fallbackRegion = allRegions.last()
+    }
+}

src/main/resources/application.yaml

@@ -14,12 +14,11 @@ quarkus:
   flyway:
     migrate-at-start: true
   oidc:
-    auth-server-url: ${HYDRA_URL:http://localhost:4444}
+    auth-server-url: ${HYDRA_URL:https://hydra.faforever.com}
     # A tenant for our self-signed JWTs
     # (also requires the CustomTenantResolver)
     self-tenant:
       # There is no .well-known/openid-configuration
-      auth-server-url: ${SELF_URL:https://ice.faforever.com}
       discovery-enabled: false
       token:
         # Hard coded JWT settings, as there is no JWKS
@@ -40,6 +39,8 @@ quarkus:
 faf:
   self-url: ${SELF_URL:https://ice.faforever.com}
   environment: ${ENVIRONMENT:dev}
+  real-ip-header: ${REAL_IP_HEADER:X-Real-Ip}
+
   token-lifetime-seconds: 86400 # 24h because of lobbies/games/reconnects can happen for a long time
   max-session-life-time-hours: 24
 xirsys:
@@ -49,6 +50,7 @@ xirsys:
   secret: ${XIRSYS_SECRET}
   channel-namespace: "faf"
   turn-enabled: ${XIRSYS_TURN_ENABLED:true}
+  geo-ip-path: ${GEO_IP_DATABASE_PATH:"/geoip/GeoLite2-City.mmdb"}
 smallrye:
   jwt:
     sign:
@@ -108,4 +110,4 @@ smallrye:
         "com.faforever":
            level: DEBUG
         "io.quarkus":
-           level: DEBUG
+           level: INFO