chore: improve netty usage (#404)

Signed-off-by: Kavindu Dodanduwa <[email protected]>

Author: Kavindu-Dodan

providers/flagd/pom.xml

@@ -54,7 +54,7 @@
             <!-- we only support unix sockets on linux, via epoll native lib -->
             <groupId>io.netty</groupId>
             <artifactId>netty-transport-native-epoll</artifactId>
-            <version>4.1.95.Final</version>
+            <version>4.1.96.Final</version>
             <!-- TODO: with 5+ (still alpha), arm is support and we should package multiple versions -->
             <classifier>linux-x86_64</classifier>
         </dependency>

providers/flagd/src/main/java/dev/openfeature/contrib/providers/flagd/grpc/GrpcConnector.java

@@ -10,6 +10,7 @@
 import io.grpc.netty.GrpcSslContexts;
 import io.grpc.netty.NettyChannelBuilder;
 import io.grpc.stub.StreamObserver;
+import io.netty.channel.epoll.Epoll;
 import io.netty.channel.epoll.EpollDomainSocketChannel;
 import io.netty.channel.epoll.EpollEventLoopGroup;
 import io.netty.channel.unix.DomainSocketAddress;
@@ -192,6 +193,11 @@ private static void busyWaitAndCheck(final Long deadline, final AtomicBoolean ch
     private static ManagedChannel nettyChannel(final FlagdOptions options) {
         // we have a socket path specified, build a channel with a unix socket
         if (options.getSocketPath() != null) {
+            // check epoll availability
+            if (!Epoll.isAvailable()) {
+                throw new IllegalStateException("unix socket cannot be used", Epoll.unavailabilityCause());
+            }
+
             return NettyChannelBuilder
                     .forAddress(new DomainSocketAddress(options.getSocketPath()))
                     .eventLoopGroup(new EpollEventLoopGroup())

providers/flagd/src/test/java/dev/openfeature/contrib/providers/flagd/grpc/GrpcConnectorTest.java

@@ -10,6 +10,9 @@
 import io.netty.channel.epoll.EpollEventLoopGroup;
 import io.netty.channel.unix.DomainSocketAddress;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledIf;
+import org.junit.jupiter.api.condition.EnabledOnOs;
+import org.junit.jupiter.api.condition.OS;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
 import org.mockito.MockedConstruction;
@@ -124,8 +127,9 @@ void initialization_fail_with_timeout() throws Exception {
     }
 
     @Test
-    void path_arg_should_build_domain_socket_with_correct_path() {
-        final String path = "/some/path";
+    void host_and_port_arg_should_build_tcp_socket() {
+        final String host = "host.com";
+        final int port = 1234;
 
         ServiceGrpc.ServiceBlockingStub mockBlockingStub = mock(ServiceGrpc.ServiceBlockingStub.class);
         ServiceGrpc.ServiceStub mockStub = mock(ServiceGrpc.ServiceStub.class);
@@ -139,31 +143,25 @@ void path_arg_should_build_domain_socket_with_correct_path() {
 
             try (MockedStatic<NettyChannelBuilder> mockStaticChannelBuilder = mockStatic(NettyChannelBuilder.class)) {
 
-                try (MockedConstruction<EpollEventLoopGroup> mockEpollEventLoopGroup = mockConstruction(
-                        EpollEventLoopGroup.class,
-                        (mock, context) -> {
-                        })) {
-                    when(NettyChannelBuilder.forAddress(any(DomainSocketAddress.class))).thenReturn(mockChannelBuilder);
+                mockStaticChannelBuilder.when(() -> NettyChannelBuilder
+                        .forAddress(anyString(), anyInt())).thenReturn(mockChannelBuilder);
 
-                    new GrpcConnector(FlagdOptions.builder().socketPath(path).build(), null, null);
+                final FlagdOptions flagdOptions = FlagdOptions.builder().host(host).port(port).tls(false).build();
+                new GrpcConnector(flagdOptions, null, null);
 
-                    // verify path matches
-                    mockStaticChannelBuilder.verify(() -> NettyChannelBuilder
-                            .forAddress(argThat((DomainSocketAddress d) -> {
-                                assertEquals(d.path(), path); // path should match
-                                return true;
-                            })), times(1));
-                }
+                // verify host/port matches
+                mockStaticChannelBuilder.verify(() -> NettyChannelBuilder
+                        .forAddress(host, port), times(1));
             }
         }
     }
 
     @Test
-    void no_args_socket_env_should_build_domain_socket_with_correct_path() throws Exception {
-        final String path = "/some/other/path";
-
-        new EnvironmentVariables("FLAGD_SOCKET_PATH", path).execute(() -> {
+    void no_args_host_and_port_env_set_should_build_tcp_socket() throws Exception {
+        final String host = "server.com";
+        final int port = 4321;
 
+        new EnvironmentVariables("FLAGD_HOST", host, "FLAGD_PORT", String.valueOf(port)).execute(() -> {
             ServiceGrpc.ServiceBlockingStub mockBlockingStub = mock(ServiceGrpc.ServiceBlockingStub.class);
             ServiceGrpc.ServiceStub mockStub = mock(ServiceGrpc.ServiceStub.class);
             NettyChannelBuilder mockChannelBuilder = getMockChannelBuilderSocket();
@@ -177,30 +175,27 @@ void no_args_socket_env_should_build_domain_socket_with_correct_path() throws Ex
                 try (MockedStatic<NettyChannelBuilder> mockStaticChannelBuilder = mockStatic(
                         NettyChannelBuilder.class)) {
 
-                    try (MockedConstruction<EpollEventLoopGroup> mockEpollEventLoopGroup = mockConstruction(
-                            EpollEventLoopGroup.class,
-                            (mock, context) -> {
-                            })) {
-                        mockStaticChannelBuilder.when(() -> NettyChannelBuilder
-                                .forAddress(any(DomainSocketAddress.class))).thenReturn(mockChannelBuilder);
+                    mockStaticChannelBuilder.when(() -> NettyChannelBuilder
+                            .forAddress(anyString(), anyInt())).thenReturn(mockChannelBuilder);
 
-                        new GrpcConnector(FlagdOptions.builder().build(), null, null);
+                    new GrpcConnector(FlagdOptions.builder().build(), null, null);
 
-                        //verify path matches & called times(= 1 as we rely on reusable channel)
-                        mockStaticChannelBuilder.verify(() -> NettyChannelBuilder
-                                .forAddress(argThat((DomainSocketAddress d) -> {
-                                    return d.path() == path;
-                                })), times(1));
-                    }
+                    // verify host/port matches & called times(= 1 as we rely on reusable channel)
+                    mockStaticChannelBuilder.verify(() -> NettyChannelBuilder.
+                            forAddress(host, port), times(1));
                 }
             }
         });
     }
 
+
+    /**
+     * OS Specific test - This test is valid only on Linux system as it rely on epoll availability
+    * */
     @Test
-    void host_and_port_arg_should_build_tcp_socket() {
-        final String host = "host.com";
-        final int port = 1234;
+    @EnabledOnOs(OS.LINUX)
+    void path_arg_should_build_domain_socket_with_correct_path() {
+        final String path = "/some/path";
 
         ServiceGrpc.ServiceBlockingStub mockBlockingStub = mock(ServiceGrpc.ServiceBlockingStub.class);
         ServiceGrpc.ServiceStub mockStub = mock(ServiceGrpc.ServiceStub.class);
@@ -214,25 +209,35 @@ void host_and_port_arg_should_build_tcp_socket() {
 
             try (MockedStatic<NettyChannelBuilder> mockStaticChannelBuilder = mockStatic(NettyChannelBuilder.class)) {
 
-                mockStaticChannelBuilder.when(() -> NettyChannelBuilder
-                        .forAddress(anyString(), anyInt())).thenReturn(mockChannelBuilder);
+                try (MockedConstruction<EpollEventLoopGroup> mockEpollEventLoopGroup = mockConstruction(
+                        EpollEventLoopGroup.class,
+                        (mock, context) -> {
+                        })) {
+                    when(NettyChannelBuilder.forAddress(any(DomainSocketAddress.class))).thenReturn(mockChannelBuilder);
 
-                final FlagdOptions flagdOptions = FlagdOptions.builder().host(host).port(port).tls(false).build();
-                new GrpcConnector(flagdOptions, null, null);
+                    new GrpcConnector(FlagdOptions.builder().socketPath(path).build(), null, null);
 
-                // verify host/port matches
-                mockStaticChannelBuilder.verify(() -> NettyChannelBuilder
-                        .forAddress(host, port), times(1));
+                    // verify path matches
+                    mockStaticChannelBuilder.verify(() -> NettyChannelBuilder
+                            .forAddress(argThat((DomainSocketAddress d) -> {
+                                assertEquals(d.path(), path); // path should match
+                                return true;
+                            })), times(1));
+                }
             }
         }
     }
 
+    /**
+     * OS Specific test - This test is valid only on Linux system as it rely on epoll availability
+     * */
     @Test
-    void no_args_host_and_port_env_set_should_build_tcp_socket() throws Exception {
-        final String host = "server.com";
-        final int port = 4321;
+    @EnabledOnOs(OS.LINUX)
+    void no_args_socket_env_should_build_domain_socket_with_correct_path() throws Exception {
+        final String path = "/some/other/path";
+
+        new EnvironmentVariables("FLAGD_SOCKET_PATH", path).execute(() -> {
 
-        new EnvironmentVariables("FLAGD_HOST", host, "FLAGD_PORT", String.valueOf(port)).execute(() -> {
             ServiceGrpc.ServiceBlockingStub mockBlockingStub = mock(ServiceGrpc.ServiceBlockingStub.class);
             ServiceGrpc.ServiceStub mockStub = mock(ServiceGrpc.ServiceStub.class);
             NettyChannelBuilder mockChannelBuilder = getMockChannelBuilderSocket();
@@ -246,14 +251,21 @@ void no_args_host_and_port_env_set_should_build_tcp_socket() throws Exception {
                 try (MockedStatic<NettyChannelBuilder> mockStaticChannelBuilder = mockStatic(
                         NettyChannelBuilder.class)) {
 
-                    mockStaticChannelBuilder.when(() -> NettyChannelBuilder
-                            .forAddress(anyString(), anyInt())).thenReturn(mockChannelBuilder);
+                    try (MockedConstruction<EpollEventLoopGroup> mockEpollEventLoopGroup = mockConstruction(
+                            EpollEventLoopGroup.class,
+                            (mock, context) -> {
+                            })) {
+                        mockStaticChannelBuilder.when(() -> NettyChannelBuilder
+                                .forAddress(any(DomainSocketAddress.class))).thenReturn(mockChannelBuilder);
 
-                    new GrpcConnector(FlagdOptions.builder().build(), null, null);
+                        new GrpcConnector(FlagdOptions.builder().build(), null, null);
 
-                    // verify host/port matches & called times(= 1 as we rely on reusable channel)
-                    mockStaticChannelBuilder.verify(() -> NettyChannelBuilder.
-                            forAddress(host, port), times(1));
+                        //verify path matches & called times(= 1 as we rely on reusable channel)
+                        mockStaticChannelBuilder.verify(() -> NettyChannelBuilder
+                                .forAddress(argThat((DomainSocketAddress d) -> {
+                                    return d.path() == path;
+                                })), times(1));
+                    }
                 }
             }
         });