random java.lang.NullPointerException: networkMode was not specified

In our ci builds we see random failures every other build saying a container can't be started. Our scenario is the following:

• We have a container running our application
• We have another container (BrowserWebDriverContainer) to run chrome
• We have specified a network for both
• The chrome container depends on the application container.

The code looks like this:

private void createContainers() {
	Network network = Network.newNetwork();
	GenericContainer<?> applicationContainer = new ApplicationContainer();
	applicationContainer.withNetwork(network).withNetworkAliases("app").withExposedPorts(8080, 8443);

	BrowserWebDriverContainer<?> chrome = new BrowserWebDriverContainer<>(
			DockerImageName.parse("selenium/standalone-chrome-debug:3.141.59-20210713")
					.asCompatibleSubstituteFor("selenium/standalone-chrome-debug"));
	chrome.withNetwork(network).withRecordingMode(VncRecordingMode.SKIP, null).dependsOn(applicationContainer);
	
	chrome.start();
}

In this scenario, ApplicationContainer extends GenericContainer<ApplicationContainer>. The code works most of the time. As said, every now and then we see the following error which makes the test run fail.

We are using testcontainers 1.15.3 right now.

java.lang.RuntimeException: com.github.dockerjava.zerodep.shaded.org.apache.hc.core5.http.NoHttpResponseException: localhost:2375 failed to respond
	at com.github.dockerjava.zerodep.ApacheDockerHttpClientImpl.execute(ApacheDockerHttpClientImpl.java:165) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.ZerodepDockerHttpClient.execute(ZerodepDockerHttpClient.java:8) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at org.testcontainers.shaded.com.github.dockerjava.core.DefaultInvocationBuilder.execute(DefaultInvocationBuilder.java:228) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.shaded.com.github.dockerjava.core.DefaultInvocationBuilder.post(DefaultInvocationBuilder.java:124) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.shaded.com.github.dockerjava.core.exec.CreateNetworkCmdExec.execute(CreateNetworkCmdExec.java:27) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.shaded.com.github.dockerjava.core.exec.CreateNetworkCmdExec.execute(CreateNetworkCmdExec.java:12) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.shaded.com.github.dockerjava.core.exec.AbstrSyncDockerCmdExec.exec(AbstrSyncDockerCmdExec.java:21) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.shaded.com.github.dockerjava.core.command.AbstrDockerCmd.exec(AbstrDockerCmd.java:35) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.containers.Network$NetworkImpl.create(Network.java:92) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.containers.Network$NetworkImpl.getId(Network.java:63) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.containers.GenericContainer.applyConfiguration(GenericContainer.java:813) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.containers.GenericContainer.tryStart(GenericContainer.java:359) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.containers.GenericContainer.lambda$doStart$0(GenericContainer.java:325) ~[testcontainers-1.15.3.jar:?]
	at org.rnorth.ducttape.unreliables.Unreliables.retryUntilSuccess(Unreliables.java:81) ~[duct-tape-1.0.8.jar:?]
	at org.testcontainers.containers.GenericContainer.doStart(GenericContainer.java:323) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.containers.GenericContainer.start(GenericContainer.java:311) ~[testcontainers-1.15.3.jar:?]
	at java.util.concurrent.CompletableFuture.uniRun(CompletableFuture.java:719) [?:1.8.0_281]
	at java.util.concurrent.CompletableFuture$UniRun.tryFire(CompletableFuture.java:701) [?:1.8.0_281]
	at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:456) [?:1.8.0_281]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_281]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_281]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_281]
Caused by: com.github.dockerjava.zerodep.shaded.org.apache.hc.core5.http.NoHttpResponseException: localhost:2375 failed to respond
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.core5.http.impl.io.DefaultHttpResponseParser.createConnectionClosedException(DefaultHttpResponseParser.java:87) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.core5.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:243) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.core5.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:53) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.core5.http.impl.io.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:187) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.core5.http.impl.io.HttpRequestExecutor.execute(HttpRequestExecutor.java:175) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.HijackingHttpRequestExecutor.execute(HijackingHttpRequestExecutor.java:50) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.core5.http.impl.io.HttpRequestExecutor.execute(HttpRequestExecutor.java:218) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.io.PoolingHttpClientConnectionManager$InternalConnectionEndpoint.execute(PoolingHttpClientConnectionManager.java:596) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.InternalExecRuntime.execute(InternalExecRuntime.java:215) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.MainClientExec.execute(MainClientExec.java:107) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ExecChainElement.execute(ExecChainElement.java:51) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ExecChainElement$1.proceed(ExecChainElement.java:57) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ConnectExec.execute(ConnectExec.java:181) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ExecChainElement.execute(ExecChainElement.java:51) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ExecChainElement$1.proceed(ExecChainElement.java:57) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ProtocolExec.execute(ProtocolExec.java:172) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ExecChainElement.execute(ExecChainElement.java:51) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ExecChainElement$1.proceed(ExecChainElement.java:57) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.HttpRequestRetryExec.execute(HttpRequestRetryExec.java:93) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ExecChainElement.execute(ExecChainElement.java:51) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ExecChainElement$1.proceed(ExecChainElement.java:57) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ContentCompressionExec.execute(ContentCompressionExec.java:128) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ExecChainElement.execute(ExecChainElement.java:51) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ExecChainElement$1.proceed(ExecChainElement.java:57) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.RedirectExec.execute(RedirectExec.java:116) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.ExecChainElement.execute(ExecChainElement.java:51) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.InternalHttpClient.doExecute(InternalHttpClient.java:178) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.shaded.org.apache.hc.client5.http.impl.classic.CloseableHttpClient.execute(CloseableHttpClient.java:67) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	at com.github.dockerjava.zerodep.ApacheDockerHttpClientImpl.execute(ApacheDockerHttpClientImpl.java:161) ~[docker-java-transport-zerodep-3.2.8.jar:?]
	... 21 more
ERROR our-image:latest] - Could not start container
java.lang.NullPointerException: networkMode was not specified
	at java.util.Objects.requireNonNull(Objects.java:228) ~[?:1.8.0_281]
	at com.github.dockerjava.api.command.CreateContainerCmd.withNetworkMode(CreateContainerCmd.java:294) ~[docker-java-api-3.2.8.jar:?]
	at org.testcontainers.containers.GenericContainer.applyConfiguration(GenericContainer.java:813) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.containers.GenericContainer.tryStart(GenericContainer.java:359) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.containers.GenericContainer.lambda$doStart$0(GenericContainer.java:325) ~[testcontainers-1.15.3.jar:?]
	at org.rnorth.ducttape.unreliables.Unreliables.retryUntilSuccess(Unreliables.java:81) ~[duct-tape-1.0.8.jar:?]
	at org.testcontainers.containers.GenericContainer.doStart(GenericContainer.java:323) ~[testcontainers-1.15.3.jar:?]
	at org.testcontainers.containers.GenericContainer.start(GenericContainer.java:311) ~[testcontainers-1.15.3.jar:?]
	at java.util.concurrent.CompletableFuture.uniRun(CompletableFuture.java:719) [?:1.8.0_281]
	at java.util.concurrent.CompletableFuture$UniRun.tryFire(CompletableFuture.java:701) [?:1.8.0_281]
	at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:456) [?:1.8.0_281]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_281]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_281]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_281]
ERROR our-image:latest] - Could not start container

GenericContainer.java の applyConfiguration 付近と Network.java の getId 付近から始め、Testcontainers 1.15.3 で、示されている 2 つのコンテナが共有ネットワークを使用するシナリオを再現します。断続的な起動で networkMode NullPointerException に到達しなくなり、アプリケーションコンテナと Chrome コンテナが正常に起動すれば完了です。