Fix webapp startup if no docker IP's set.

infrastructures/docker/infrastructure/src/main/java/org/eclipse/che/workspace/infrastructure/docker/provisioner/labels/SinglePortLabelsProvisioner.java

@@ -42,17 +42,21 @@ public class SinglePortLabelsProvisioner implements ConfigurationProvisioner {
 
   @Inject
   public SinglePortLabelsProvisioner(
+      @Named("che.single.port") boolean isSinglePortEnabled,
       @Nullable @Named("che.docker.ip") String internalIpOfContainers,
       @Nullable @Named("che.docker.ip.external") String externalIpOfContainers,
       @Nullable @Named("che.docker.network") String dockerNetwork,
       @Nullable @Named("che.singleport.wildcard_domain.host") String wildcardHost) {
-    if (internalIpOfContainers == null && externalIpOfContainers == null) {
+    if (isSinglePortEnabled && internalIpOfContainers == null && externalIpOfContainers == null) {
       throw new IllegalStateException(
           "Value of both of the properties 'che.docker.ip' and 'che.docker.ip.external' is null,"
               + " which is unsuitable for the single-port mode");
     }
     this.hostnameBuilder =
-        new SinglePortHostnameBuilder(externalIpOfContainers, internalIpOfContainers, wildcardHost);
+        isSinglePortEnabled
+            ? new SinglePortHostnameBuilder(
+                externalIpOfContainers, internalIpOfContainers, wildcardHost)
+            : null;
     this.internalIpOfContainers = internalIpOfContainers;
     this.externalIpOfContainers = externalIpOfContainers;
     this.dockerNetwork = dockerNetwork;

infrastructures/docker/infrastructure/src/main/java/org/eclipse/che/workspace/infrastructure/docker/server/mapping/SinglePortUrlRewriter.java

@@ -35,17 +35,21 @@ public class SinglePortUrlRewriter implements URLRewriter {
 
   @Inject
   public SinglePortUrlRewriter(
+      @Named("che.single.port") boolean isSinglePortEnabled,
       @Nullable @Named("che.docker.ip") String internalIpOfContainers,
       @Named("che.port") int chePort,
       @Nullable @Named("che.docker.ip.external") String externalIpOfContainers,
       @Nullable @Named("che.singleport.wildcard_domain.host") String wildcardHost) {
-    if (internalIpOfContainers == null && externalIpOfContainers == null) {
+    if (isSinglePortEnabled && internalIpOfContainers == null && externalIpOfContainers == null) {
       throw new IllegalStateException(
           "Value of both of the properties 'che.docker.ip' and 'che.docker.ip.external' is null,"
               + " which is unsuitable for the single-port mode");
     }
     this.hostnameBuilder =
-        new SinglePortHostnameBuilder(externalIpOfContainers, internalIpOfContainers, wildcardHost);
+        isSinglePortEnabled
+            ? new SinglePortHostnameBuilder(
+                externalIpOfContainers, internalIpOfContainers, wildcardHost)
+            : null;
     this.chePort = chePort;
   }
 

infrastructures/docker/infrastructure/src/test/java/org/eclipse/che/workspace/infrastructure/docker/server/mapping/SinglePortUrlRewriterTest.java

@@ -33,7 +33,7 @@ public void shouldRewriteURL(
       String expectedURL)
       throws Exception {
     SinglePortUrlRewriter rewriter =
-        new SinglePortUrlRewriter(externalIP, 8080, internalIp, nioHost);
+        new SinglePortUrlRewriter(true, externalIP, 8080, internalIp, nioHost);
 
     String rewrittenURL = rewriter.rewriteURL(identity, machineName, serverName, incomeURL);
 
@@ -97,7 +97,7 @@ public static Object[][] urlRewritingTestProvider() {
   )
   public void shouldThrowExceptionWhenRewritingFails() throws Exception {
     SinglePortUrlRewriter rewriter =
-        new SinglePortUrlRewriter("127.0.0.1", 8080, "172.12.0.2", null);
+        new SinglePortUrlRewriter(true, "127.0.0.1", 8080, "172.12.0.2", null);
     rewriter.rewriteURL(new RuntimeIdentityImpl("ws123", null, null), "machine1", "server", ":");
   }
 }