wda: add USE_IP env var to override what IP to bind to for multi-simulator scenarios

Signed-off-by: Karl Baumgartner <178656887+karlbaumg@users.noreply.github.com>

Author: karlbaumg

WebDriverAgent.xcodeproj/xcshareddata/xcschemes/WebDriverAgentRunner.xcscheme

@@ -66,6 +66,11 @@
             value = "$(USE_PORT)"
             isEnabled = "YES">
          </EnvironmentVariable>
+         <EnvironmentVariable
+            key = "USE_IP"
+            value = "$(USE_IP)"
+            isEnabled = "YES">
+         </EnvironmentVariable>
          <EnvironmentVariable
             key = "UPGRADE_TIMESTAMP"
             value = "$(UPGRADE_TIMESTAMP)"

WebDriverAgent.xcodeproj/xcshareddata/xcschemes/WebDriverAgentRunner_tvOS.xcscheme

@@ -75,6 +75,11 @@
             value = "$(USE_PORT)"
             isEnabled = "YES">
          </EnvironmentVariable>
+         <EnvironmentVariable
+            key = "USE_IP"
+            value = "$(USE_IP)"
+            isEnabled = "YES">
+         </EnvironmentVariable>
          <EnvironmentVariable
             key = "UPGRADE_TIMESTAMP"
             value = "$(UPGRADE_TIMESTAMP)"

WebDriverAgentLib/Routing/FBWebServer.m

@@ -92,6 +92,12 @@ - (void)startHTTPServer
   [self registerServerKeyRouteHandlers];
 
   NSRange serverPortRange = FBConfiguration.bindingPortRange;
+  NSString *bindingIP = FBConfiguration.bindingIPAddress;
+  if (bindingIP != nil) {
+    [self.server setInterface:bindingIP];
+    [FBLogger logFmt:@"Using custom binding IP address: %@", bindingIP];
+  }
+  
   NSError *error;
   BOOL serverStarted = NO;
 

WebDriverAgentLib/Utilities/FBConfiguration.h

@@ -124,6 +124,12 @@ extern NSString *const FBSnapshotMaxDepthKey;
  */
 + (NSRange)bindingPortRange;
 
+/**
+ The IP address that the HTTP Server should bind to on launch.
+ Returns nil if not specified, which causes the server to listen on all interfaces.
+ */
++ (NSString * _Nullable)bindingIPAddress;
+
 /**
  The port number where the background screenshots broadcaster is supposed to run
  */

WebDriverAgentLib/Utilities/FBConfiguration.m

@@ -137,6 +137,17 @@ + (NSRange)bindingPortRange
   return NSMakeRange(DefaultStartingPort, DefaultPortRange);
 }
 
++ (NSString *)bindingIPAddress
+{
+  // Existence of USE_IP in the environment allows specifying which interface to bind to
+  if (NSProcessInfo.processInfo.environment[@"USE_IP"] &&
+      [NSProcessInfo.processInfo.environment[@"USE_IP"] length] > 0) {
+    return NSProcessInfo.processInfo.environment[@"USE_IP"];
+  }
+
+  return nil;
+}
+
 + (NSInteger)mjpegServerPort
 {
   if (self.mjpegServerPortFromArguments != NSNotFound) {

WebDriverAgentTests/UnitTests/FBConfigurationTests.m

@@ -20,6 +20,7 @@ - (void)setUp
 {
   [super setUp];
   unsetenv("USE_PORT");
+  unsetenv("USE_IP");
   unsetenv("VERBOSE_LOGGING");
 }
 
@@ -45,4 +46,15 @@ - (void)testVerboseLoggingEnvironmentOverwrite
   XCTAssertTrue([FBConfiguration verboseLoggingEnabled]);
 }
 
+- (void)testBindingIPDefault
+{
+  XCTAssertNil([FBConfiguration bindingIPAddress]);
+}
+
+- (void)testBindingIPEnvironmentOverwrite
+{
+  setenv("USE_IP", "192.168.1.100", 1);
+  XCTAssertEqualObjects([FBConfiguration bindingIPAddress], @"192.168.1.100");
+}
+
 @end