Allow Kitura-NIO to only listen on one network address

Sources/KituraNet/FastCGI/FastCGIServer.swift

@@ -29,6 +29,10 @@ public class FastCGIServer: Server {
     /// Port number for listening for new connections
     public private(set) var port: Int?
 
+    /// The address of a network interface to listen on, for example "localhost". The default is nil,
+    /// which listens for connections on all interfaces.
+    public private(set) var address: String?
+
     /// A server state.
     public private(set) var state: ServerState = .unknown
 
@@ -53,17 +57,21 @@ public class FastCGIServer: Server {
     /// Listens for connections on a socket
     ///
     /// - Parameter on: port number for new connections
-    public func listen(on port: Int) throws {
+    /// - Parameter address: The address of the network interface to listen on. Defaults to nil, which means this
+    ///             server will listen on all interfaces.
+    public func listen(on port: Int, address: String? = nil) throws {
         fatalError("FastCGI is not implemented yet.")
     }
 
     /// Static method to create a new `FastCGIServer` and have it listen for conenctions
     ///
     /// - Parameter on: port number for accepting new connections
+    /// - Parameter address: The address of the network interface to listen on. Defaults to nil, which means this
+    ///             server will listen on all interfaces.
     /// - Parameter delegate: the delegate handler for FastCGI/HTTP connections
     ///
     /// - Returns: a new `FastCGIServer` instance
-    public static func listen(on port: Int, delegate: ServerDelegate?) throws -> FastCGIServer {
+    public static func listen(on port: Int, address: String? = nil, delegate: ServerDelegate?) throws -> FastCGIServer {
         fatalError("FastCGI not implemented yet.")
     }
 

Sources/KituraNet/HTTP/HTTPServer.swift

@@ -58,6 +58,10 @@ public class HTTPServer: Server {
     /// The TCP port on which this server listens for new connections. If `nil`, this server does not listen on a TCP socket.
     public private(set) var port: Int?
 
+    /// The address of a network interface to listen on, for example "localhost". The default is nil,
+    /// which listens for connections on all interfaces.
+    public private(set) var address: String?
+
     /// The Unix domain socket path on which this server listens for new connections. If `nil`, this server does not listen on a Unix socket.
     public private(set) var unixDomainSocketPath: String?
 
@@ -232,8 +236,8 @@ public class HTTPServer: Server {
 
     // Sockets could either be TCP/IP sockets or Unix domain sockets
     private enum SocketType {
-        // An TCP/IP socket has an associated port number
-        case tcp(Int)
+        // An TCP/IP socket has an associated port number and optional address value
+        case tcp(Int, String?)
         // A unix domain socket has an associated filename
         case unix(String)
     }
@@ -258,14 +262,17 @@ public class HTTPServer: Server {
 
      ### Usage Example: ###
      ````swift
-     try server.listen(on: 8080)
+     try server.listen(on: 8080, address: "localhost")
      ````
 
      - Parameter on: Port number for new connections, e.g. 8080
-    */
-    public func listen(on port: Int) throws {
+     - Parameter address: The address of the network interface to listen on. Defaults to nil, which means this server
+                          will listen on all interfaces.
+     */
+    public func listen(on port: Int, address: String? = nil) throws {
         self.port = port
-        try listen(.tcp(port))
+        self.address = address
+        try listen(.tcp(port, address))
     }
 
     private func listen(_ socket: SocketType) throws {
@@ -310,8 +317,8 @@ public class HTTPServer: Server {
         let listenerDescription: String
         do {
             switch socket {
-            case SocketType.tcp(let port):
-                serverChannel = try bootstrap.bind(host: "0.0.0.0", port: port).wait()
+            case SocketType.tcp(let port, let address):
+                serverChannel = try bootstrap.bind(host: address ?? "0.0.0.0", port: port).wait()
                 self.port = serverChannel?.localAddress?.port.map { Int($0) }
                 listenerDescription = "port \(self.port ?? port)"
             case SocketType.unix(let unixDomainSocketPath):
@@ -360,18 +367,20 @@ public class HTTPServer: Server {
 
      ### Usage Example: ###
      ````swift
-     let server = HTTPServer.listen(on: 8080, delegate: self)
+     let server = HTTPServer.listen(on: 8080, node: "localhost", delegate: self)
      ````
 
      - Parameter on: Port number for accepting new connections.
+     - Parameter address: The address of the network interface to listen on. Defaults to nil, which means this server
+                 will listen on all interfaces.
      - Parameter delegate: The delegate handler for HTTP connections.
 
      - Returns: A new instance of a `HTTPServer`.
     */
-    public static func listen(on port: Int, delegate: ServerDelegate?) throws -> ServerType {
+    public static func listen(on port: Int, address: String? = nil, delegate: ServerDelegate?) throws -> ServerType {
         let server = HTTP.createServer()
         server.delegate = delegate
-        try server.listen(on: port)
+        try server.listen(on: port, address: address)
         return server
     }
 

Sources/KituraNet/Server/Server.swift

@@ -26,14 +26,35 @@ public protocol Server {
     /// Port number for listening for new connections.
     var port: Int? { get }
 
+    /// The address of a network interface to listen on, for example "localhost". The default is nil,
+    /// which listens for connections on all interfaces.
+    var address: String? { get }
+
     /// A server state.
     var state: ServerState { get }
 
+    /// Listen for connections on a socket.
+    ///
+    /// - Parameter on: port number for new connections (eg. 8080)
+    /// - Parameter address: The address of the network interface to listen on. Defaults to nil, which means this
+    ///             server will listen on all interfaces.
+    func listen(on port: Int, address: String?) throws
+
     /// Listen for connections on a socket.
     ///
     /// - Parameter on: port number for new connections (eg. 8080)
     func listen(on port: Int) throws
 
+    /// Static method to create a new Server and have it listen for connections.
+    ///
+    /// - Parameter on: port number for accepting new connections
+    /// - Parameter address: The address of the network interface to listen on. Defaults to nil, which means this
+    ///             server will listen on all interfaces.
+    /// - Parameter delegate: the delegate handler for HTTP connections
+    ///
+    /// - Returns: a new Server instance
+    static func listen(on port: Int, address: String?, delegate: ServerDelegate?) throws -> ServerType
+
     /// Static method to create a new Server and have it listen for connections.
     ///
     /// - Parameter on: port number for accepting new connections
@@ -94,3 +115,12 @@ public protocol Server {
     @discardableResult
     func clientConnectionFailed(callback: @escaping (Swift.Error) -> Void) -> Self
 }
+
+extension Server {
+    public func listen(on port: Int) throws {
+        try listen(on: port, address: nil)
+    }
+    public static func listen(on port: Int, delegate: ServerDelegate?) throws -> ServerType {
+        return try Self.listen(on: port, address: nil, delegate: delegate)
+    }
+}

Tests/KituraNetTests/ClientE2ETests.swift

@@ -93,7 +93,7 @@ class ClientE2ETests: KituraNetTest {
 
     func testEphemeralListeningPort() {
         do {
-            let server = try HTTPServer.listen(on: 0, delegate: delegate)
+            let server = try HTTPServer.listen(on: 0, address: "localhost", delegate: delegate)
             _ = HTTP.get("http://localhost:\(server.port!)") { response in
                 XCTAssertNotNil(response, "ERROR!!! ClientRequest response object was nil")
                 XCTAssertEqual(response?.statusCode, HTTPStatusCode.OK, "HTTP Status code was \(String(describing: response?.statusCode))")

Tests/KituraNetTests/KituraNIOTest.swift

@@ -96,7 +96,7 @@ class KituraNetTest: XCTestCase {
             try server.listen(unixDomainSocketPath: unixDomainSocketPath)
         } else {
             server.allowPortReuse = allowPortReuse
-            try server.listen(on: port)
+            try server.listen(on: port, address: "localhost")
         }
         return server
     }

Tests/KituraNetTests/LifecycleListenerTests.swift

@@ -55,7 +55,7 @@ class LifecycleListenerTests: KituraNetTest {
         }
 
         do {
-            try server.listen(on: 0)
+            try server.listen(on: 0, address: "localhost")
 
             self.waitForExpectations(timeout: 5) { error in
                 XCTAssertNil(error)
@@ -127,7 +127,7 @@ class LifecycleListenerTests: KituraNetTest {
         }
 
         do {
-            try server.listen(on: 0)
+            try server.listen(on: 0, address: "localhost")
 
             self.waitForExpectations(timeout: 5) { error in
                 XCTAssertNil(error)
@@ -155,7 +155,7 @@ class LifecycleListenerTests: KituraNetTest {
         })
 
         do {
-            try server.listen(on: -1)
+            try server.listen(on: -1, address: nil)
         } catch {
             // Do NOT fail the test if an error is thrown.
             // In this test case an error should be thrown.

Tests/KituraNetTests/MonitoringTests.swift

@@ -65,7 +65,7 @@ class MonitoringTests: KituraNetTest {
         }
 
         do {
-            try server.listen(on: 0)
+            try server.listen(on: 0, address: nil)
             self.waitForExpectations(timeout: 10) { error in
                 server.stop()
                 XCTAssertNil(error)

Tests/KituraNetTests/PipeliningTests.swift

@@ -47,7 +47,7 @@ class PipeliningTests: KituraNetTest {
         let server = HTTPServer()
         server.delegate = Delegate()
         do {
-            try server.listen(on: 0)
+            try server.listen(on: 0, address: "localhost")
         } catch let error {
             Log.error("Server failed to listen. Error: \(error)")
         }
@@ -85,7 +85,7 @@ class PipeliningTests: KituraNetTest {
         server.delegate = Delegate()
         server.delegate = Delegate()
         do {
-            try server.listen(on: 0)
+            try server.listen(on: 0, address: "localhost")
         } catch let error {
             Log.error("Server failed to listen. Error: \(error)")
         }