docker-java · marcuslinke · Dec 11, 2014 · Dec 9, 2014 · Dec 9, 2014
diff --git a/src/main/java/com/github/dockerjava/api/command/StartContainerCmd.java b/src/main/java/com/github/dockerjava/api/command/StartContainerCmd.java
@@ -24,9 +24,9 @@ public interface StartContainerCmd extends DockerCmd<Void> {
 
 	public Ports getPortBindings();
 
-	public boolean isPublishAllPorts();
+	public Boolean isPublishAllPorts();
 
-	public boolean isPrivileged();
+	public Boolean isPrivileged();
 
 	public String[] getDns();
 
@@ -70,9 +70,9 @@ public interface StartContainerCmd extends DockerCmd<Void> {
 	 */
 	public StartContainerCmd withPortBindings(PortBinding... portBindings);
 
-	public StartContainerCmd withPrivileged(boolean privileged);
+	public StartContainerCmd withPrivileged(Boolean privileged);
 
-	public StartContainerCmd withPublishAllPorts(boolean publishAllPorts);
+	public StartContainerCmd withPublishAllPorts(Boolean publishAllPorts);
 
 	/**
 	 * Set custom DNS servers

diff --git a/src/main/java/com/github/dockerjava/core/command/StartContainerCmdImpl.java b/src/main/java/com/github/dockerjava/core/command/StartContainerCmdImpl.java
@@ -1,8 +1,11 @@
 package com.github.dockerjava.core.command;
 
+import static com.fasterxml.jackson.annotation.JsonInclude.Include.NON_EMPTY;
+
 import org.apache.commons.lang.builder.ToStringBuilder;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.github.dockerjava.api.NotFoundException;
 import com.github.dockerjava.api.NotModifiedException;
@@ -22,15 +25,17 @@
 /**
  * Start a container
  */
+@JsonInclude(NON_EMPTY)
 public class StartContainerCmdImpl extends AbstrDockerCmd<StartContainerCmd, Void> implements StartContainerCmd {
 
+	@JsonIgnore
 	private String containerId;
 
 	@JsonProperty("Binds")
-	private Binds binds = new Binds();
+	private Binds binds;
 
 	@JsonProperty("Links")
-	private Links links = new Links();
+	private Links links;
 
 	@JsonProperty("LxcConf")
 	private LxcConf[] lxcConf;
@@ -39,10 +44,10 @@ public class StartContainerCmdImpl extends AbstrDockerCmd<StartContainerCmd, Voi
 	private Ports portBindings;
 
 	@JsonProperty("PublishAllPorts")
-	private boolean publishAllPorts;
+	private Boolean publishAllPorts;
 
 	@JsonProperty("Privileged")
-	private boolean privileged;
+	private Boolean privileged;
 
 	@JsonProperty("Dns")
 	private String[] dns;
@@ -54,7 +59,7 @@ public class StartContainerCmdImpl extends AbstrDockerCmd<StartContainerCmd, Voi
 	private String volumesFrom;
 
 	@JsonProperty("NetworkMode")          
-    private String networkMode = "bridge";
+    private String networkMode;
 
 	@JsonProperty("Devices")
 	private Device[] devices;
@@ -76,13 +81,13 @@ public StartContainerCmdImpl(StartContainerCmd.Exec exec, String containerId) {
 	@Override
 	@JsonIgnore
 	public Bind[] getBinds() {
-		return binds.getBinds();
+		return (binds == null) ? new Bind[0] : binds.getBinds();
 	}
 
 	@Override
 	@JsonIgnore
 	public Link[] getLinks() {
-		return links.getLinks();
+		return (links == null) ? new Link[0] : links.getLinks();
 	}
 
 	@Override
@@ -96,12 +101,12 @@ public Ports getPortBindings() {
 	}
 
 	@Override
-	public boolean isPublishAllPorts() {
+	public Boolean isPublishAllPorts() {
 		return publishAllPorts;
 	}
 
 	@Override
-	public boolean isPrivileged() {
+	public Boolean isPrivileged() {
 		return privileged;
 	}
 
@@ -192,13 +197,13 @@ public StartContainerCmd withPortBindings(PortBinding... portBindings) {
 	}
 
 	@Override
-	public StartContainerCmd withPrivileged(boolean privileged) {
+	public StartContainerCmd withPrivileged(Boolean privileged) {
 		this.privileged = privileged;
 		return this;
 	}
 
 	@Override
-	public StartContainerCmd withPublishAllPorts(boolean publishAllPorts) {
+	public StartContainerCmd withPublishAllPorts(Boolean publishAllPorts) {
 		this.publishAllPorts = publishAllPorts;
 		return this;
 	}

diff --git a/src/test/java/com/github/dockerjava/core/command/StartContainerCmdImplTest.java b/src/test/java/com/github/dockerjava/core/command/StartContainerCmdImplTest.java
@@ -2,6 +2,7 @@
 
 import static com.github.dockerjava.api.model.AccessMode.ro;
 import static com.github.dockerjava.api.model.Capability.*;
+import static org.hamcrest.CoreMatchers.nullValue;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.contains;
 import static org.hamcrest.Matchers.equalTo;
@@ -386,4 +387,55 @@ public void startContainerWithRestartPolicy() throws DockerException {
                 is(equalTo(restartPolicy)));
     }
 
+	@Test
+	public void existingHostConfigIsPreservedByBlankStartCmd() throws DockerException {
+
+		String dnsServer = "8.8.8.8";
+
+		// prepare a container with custom DNS 
+		CreateContainerResponse container = dockerClient
+				.createContainerCmd("busybox")
+				.withDns(dnsServer)
+				.withCmd("true").exec();
+
+		LOG.info("Created container {}", container.toString());
+
+		assertThat(container.getId(), not(isEmptyString()));
+
+		// start container _without_any_customization_ (important!) 
+		dockerClient.startContainerCmd(container.getId()).exec();
+
+		InspectContainerResponse inspectContainerResponse = dockerClient.inspectContainerCmd(container
+				.getId()).exec();
+
+		// The DNS setting survived.
+		assertThat(inspectContainerResponse.getHostConfig().getDns(), is(notNullValue()));
+		assertThat(Arrays.asList(inspectContainerResponse.getHostConfig().getDns()),
+				contains(dnsServer));
+	}
+
+	@Test
+	public void existingHostConfigIsResetByConfiguredStartCmd() throws DockerException {
+
+		String dnsServer = "8.8.8.8";
+
+		// prepare a container with custom DNS 
+		CreateContainerResponse container = dockerClient
+				.createContainerCmd("busybox")
+				.withDns(dnsServer)
+				.withCmd("true").exec();
+
+		LOG.info("Created container {}", container.toString());
+
+		assertThat(container.getId(), not(isEmptyString()));
+
+		// modify another setting in start command. Leave DNS unchanged. 
+		dockerClient.startContainerCmd(container.getId()).withPublishAllPorts(true).exec();
+
+		InspectContainerResponse inspectContainerResponse = dockerClient.inspectContainerCmd(container
+				.getId()).exec();
+
+		// although start did not modify DNS Settings, they were reset to their default.
+		assertThat(inspectContainerResponse.getHostConfig().getDns(), is(nullValue(String[].class)));
+	}
 }