Fix: Create a way for networks to be reusable

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

@@ -1,6 +1,7 @@
 package org.testcontainers.containers;
 
 import com.github.dockerjava.api.command.CreateNetworkCmd;
+import com.github.dockerjava.api.command.ListNetworksCmd;
 import lombok.Builder;
 import lombok.Getter;
 import lombok.Singular;
@@ -11,15 +12,24 @@
 
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Consumer;
 
 public interface Network extends AutoCloseable, TestRule {
 
-    Network SHARED = new NetworkImpl(false, null, Collections.emptySet(), null) {
+    Network SHARED = new NetworkImpl(
+        UUID.randomUUID().toString(),
+        false,
+        false,
+        null,
+        Collections.emptySet(),
+        null
+    ) {
         @Override
         public void close() {
             // Do not allow users to close SHARED network, only ResourceReaper is allowed to close (destroy) it
@@ -35,6 +45,13 @@ static Network newNetwork() {
         return builder().build();
     }
 
+    static Network newNetwork(String networkName) {
+        return builder()
+            .name(networkName)
+            .withReuse(true)
+            .build();
+    }
+
     static NetworkImpl.NetworkImplBuilder builder() {
         return NetworkImpl.builder();
     }
@@ -43,7 +60,11 @@ static NetworkImpl.NetworkImplBuilder builder() {
     @Getter
     class NetworkImpl extends ExternalResource implements Network {
 
-        private final String name = UUID.randomUUID().toString();
+        @Builder.Default
+        private String name = UUID.randomUUID().toString();
+
+        @Builder.Default
+        private Boolean withReuse = false;
 
         private Boolean enableIpv6;
 
@@ -66,7 +87,25 @@ public synchronized String getId() {
             return id;
         }
 
+        private Optional<String> get() {
+            ListNetworksCmd listNetworksCmd = DockerClientFactory.instance().client().listNetworksCmd();
+            listNetworksCmd.withNameFilter(name);
+            List<com.github.dockerjava.api.model.Network> networks = listNetworksCmd.exec();
+            for(com.github.dockerjava.api.model.Network network : networks){
+                if(network.getName().equals(name)){
+                    return Optional.of(network.getId());
+                }
+            }
+            return Optional.empty();
+        }
+
         private String create() {
+
+            Optional<String> existingNetwork = get();
+            if(existingNetwork.isPresent()) {
+                return existingNetwork.get();
+            }
+
             CreateNetworkCmd createNetworkCmd = DockerClientFactory.instance().client().createNetworkCmd();
 
             createNetworkCmd.withName(name);
@@ -99,8 +138,10 @@ protected void after() {
 
         @Override
         public synchronized void close() {
-            if (initialized.getAndSet(false)) {
-                ResourceReaper.instance().removeNetworkById(id);
+            if(!withReuse) {
+                if (initialized.getAndSet(false)) {
+                    ResourceReaper.instance().removeNetworkById(id);
+                }
             }
         }
     }

core/src/test/java/org/testcontainers/containers/NetworkTest.java

@@ -6,6 +6,7 @@
 import org.junit.runner.RunWith;
 import org.testcontainers.DockerClientFactory;
 import org.testcontainers.TestImages;
+import org.testcontainers.utility.ResourceReaper;
 
 import static org.rnorth.visibleassertions.VisibleAssertions.assertEquals;
 import static org.rnorth.visibleassertions.VisibleAssertions.assertNotEquals;
@@ -96,6 +97,28 @@ public void testModifiers() {
             }
         }
 
+        @Test
+        public void testResuableNamedNetwork() {
+            try (Network network = Network.newNetwork("random-network-87hf8f")) {
+                String firstId = network.getId();
+                assertNotNull(
+                    "Network exists",
+                    DockerClientFactory.instance().client().inspectNetworkCmd().withNetworkId(firstId).exec()
+                );
+
+                network.close();
+
+                assertEquals(
+                    "Same network reused, network close didn't work",
+                    firstId,
+                    DockerClientFactory.instance().client().inspectNetworkCmd().withNetworkId(network.getId()).exec().getId()
+                );
+
+                // cleanup
+                ResourceReaper.instance().removeNetworkById(network.getId());
+            }
+        }
+
         @Test
         public void testReusability() {
             try (Network network = Network.newNetwork()) {