Extend 'addFixedExposedPort' method with InternetProtocol argument

core/src/main/java/org/testcontainers/containers/FixedHostPortGenericContainer.java

@@ -17,14 +17,26 @@ public FixedHostPortGenericContainer(@NotNull String dockerImageName) {
     }
 
     /**
-     * Bind a fixed port on the docker host to a container port
+     * Bind a fixed TCP port on the docker host to a container port
      * @param hostPort          a port on the docker host, which must be available
      * @param containerPort     a port in the container
      * @return                  this container
      */
     public SELF withFixedExposedPort(int hostPort, int containerPort) {
 
-        super.addFixedExposedPort(hostPort, containerPort);
+        return withFixedExposedPort(hostPort, containerPort, InternetProtocol.TCP);
+    }
+
+    /**
+     * Bind a fixed port on the docker host to a container port
+     * @param hostPort          a port on the docker host, which must be available
+     * @param containerPort     a port in the container
+     * @param protocol          an internet protocol (tcp or udp)
+     * @return                  this container
+     */
+    public SELF withFixedExposedPort(int hostPort, int containerPort, InternetProtocol protocol) {
+
+        super.addFixedExposedPort(hostPort, containerPort, protocol);
 
         return self();
     }

core/src/main/java/org/testcontainers/containers/GenericContainer.java

@@ -644,7 +644,7 @@ public SELF withExposedPorts(Integer... ports) {
     }
 
     /**
-     * Add a container port that should be bound to a fixed port on the docker host.
+     * Add a TCP container port that should be bound to a fixed port on the docker host.
      * <p>
      * Note that this method is protected scope to discourage use, as clashes or instability are more likely when
      * using fixed port mappings. If you need to use this method from a test, please use {@link FixedHostPortGenericContainer}
@@ -654,7 +654,22 @@ public SELF withExposedPorts(Integer... ports) {
      * @param containerPort
      */
     protected void addFixedExposedPort(int hostPort, int containerPort) {
-        portBindings.add(String.format("%d:%d", hostPort, containerPort));
+        addFixedExposedPort(hostPort, containerPort, InternetProtocol.TCP);
+    }
+
+    /**
+     * Add a container port that should be bound to a fixed port on the docker host.
+     * <p>
+     * Note that this method is protected scope to discourage use, as clashes or instability are more likely when
+     * using fixed port mappings. If you need to use this method from a test, please use {@link FixedHostPortGenericContainer}
+     * instead of GenericContainer.
+     *
+     * @param hostPort
+     * @param containerPort
+     * @param protocol
+     */
+    protected void addFixedExposedPort(int hostPort, int containerPort, InternetProtocol protocol) {
+        portBindings.add(String.format("%d:%d/%s", hostPort, containerPort, protocol.toDockerNotation()));
     }
 
     /**

core/src/main/java/org/testcontainers/containers/InternetProtocol.java

@@ -0,0 +1,18 @@
+package org.testcontainers.containers;
+
+/**
+ * The IP protocols supported by Docker.
+ */
+public enum InternetProtocol {
+
+    TCP,
+    UDP;
+
+    public String toDockerNotation() {
+        return name().toLowerCase();
+    }
+
+    public static InternetProtocol fromDockerNotation(String protocol) {
+        return valueOf(protocol.toUpperCase());
+    }
+}