Support configuring ZooKeeper service in container

3 files changed, 73 insertions, 1 deletions

diff --git a/config-model/src/main/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilder.java b/config-model/src/main/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilder.java
index b95571de936..b7d64483e57 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilder.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilder.java
@@ -112,6 +112,10 @@ public class ContainerModelBuilder extends ConfigModelBuilder<ContainerModel> {
     private static final String DEPRECATED_CONTAINER_TAG = "jdisc";
     private static final String ENVIRONMENT_VARIABLES_ELEMENT = "environment-variables";
 
+    // The node count to enforce in a cluster running ZooKeeper
+    private static final int MIN_ZOOKEEPER_NODE_COUNT = 3;
+    private static final int MAX_ZOOKEEPER_NODE_COUNT = 7;
+
     public enum Networking { disable, enable }
 
     private ApplicationPackage app;
@@ -195,7 +199,26 @@ public class ContainerModelBuilder extends ConfigModelBuilder<ContainerModel> {
         addClientProviders(deployState, spec, cluster);
         addServerProviders(deployState, spec, cluster);
 
-        addAthensCopperArgos(cluster, context);  // Must be added after nodes.
+        // Must be added after nodes:
+        addAthensCopperArgos(cluster, context);
+        addZooKeeper(cluster, spec);
+    }
+
+    private void addZooKeeper(ApplicationContainerCluster cluster, Element spec) {
+        Element zkElement = XML.getChild(spec, "zookeeper");
+        if (zkElement == null) return;
+        Element nodesElement = XML.getChild(spec, "nodes");
+        boolean isCombined = nodesElement != null && nodesElement.hasAttribute("of");
+        if (isCombined) {
+            throw new IllegalArgumentException("A combined cluster cannot run ZooKeeper");
+        }
+        int nodeCount = cluster.getContainers().size();
+        if (nodeCount < MIN_ZOOKEEPER_NODE_COUNT || nodeCount > MAX_ZOOKEEPER_NODE_COUNT || nodeCount % 2 == 0) {
+            throw new IllegalArgumentException("Clusters running ZooKeeper must have an odd number of nodes, between " +
+                                               MIN_ZOOKEEPER_NODE_COUNT + " and " + MAX_ZOOKEEPER_NODE_COUNT);
+        }
+        cluster.addSimpleComponent("com.yahoo.vespa.curator.Curator", null, "zkfacade");
+        // TODO: Add server component
     }
 
     private void addSecretStore(ApplicationContainerCluster cluster, Element spec) {
diff --git a/config-model/src/main/resources/schema/containercluster.rnc b/config-model/src/main/resources/schema/containercluster.rnc
index 25d10e0d9b3..ca7efd5a938 100644
--- a/config-model/src/main/resources/schema/containercluster.rnc
+++ b/config-model/src/main/resources/schema/containercluster.rnc
@@ -27,6 +27,7 @@ ContainerServices =
     Http? &
     AccessLog* &
     SecretStore? &
+    ZooKeeper? &
     GenericConfig*
 
 # TODO(ogronnesby): Change this configuration syntax
@@ -91,6 +92,10 @@ SecretStore = element secret-store {
     } +
 }
 
+ZooKeeper = element zookeeper {
+    empty
+}
+
 ModelEvaluation = element model-evaluation {
     empty
 }
diff --git a/config-model/src/test/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilderTest.java b/config-model/src/test/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilderTest.java
index 13c1631e0ce..32dd5cc944c 100644
--- a/config-model/src/test/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilderTest.java
+++ b/config-model/src/test/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilderTest.java
@@ -40,11 +40,13 @@ import com.yahoo.vespa.defaults.Defaults;
 import com.yahoo.vespa.model.AbstractService;
 import com.yahoo.vespa.model.VespaModel;
 import com.yahoo.vespa.model.container.ApplicationContainer;
+import com.yahoo.vespa.model.container.ApplicationContainerCluster;
 import com.yahoo.vespa.model.container.ContainerCluster;
 import com.yahoo.vespa.model.container.SecretStore;
 import com.yahoo.vespa.model.container.component.Component;
 import com.yahoo.vespa.model.container.http.ConnectorFactory;
 import com.yahoo.vespa.model.content.utils.ContentClusterUtils;
+import com.yahoo.vespa.model.test.VespaModelTester;
 import com.yahoo.vespa.model.test.utils.VespaModelCreatorWithFilePkg;
 import org.hamcrest.Matchers;
 import org.junit.Rule;
@@ -59,6 +61,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.logging.Level;
 import java.util.stream.Collectors;
 
@@ -871,6 +874,46 @@ public class ContainerModelBuilderTest extends ContainerModelBuilderTestBase {
         assertThat(connectorConfig.ssl().caCertificate(), isEmptyString());
     }
 
+    @Test
+    public void cluster_with_zookeeper() {
+        Function<Integer, String> servicesXml = (nodeCount) -> "<container version='1.0' id='default'>" +
+                                                               "<nodes count='" + nodeCount + "'/>" +
+                                                               "<zookeeper/>" +
+                                                               "</container>";
+        VespaModelTester tester = new VespaModelTester();
+        tester.addHosts(3);
+        {
+            VespaModel model = tester.createModel(servicesXml.apply(3), true);
+            String componentId = "com.yahoo.vespa.curator.Curator";
+            ApplicationContainerCluster cluster = model.getContainerClusters().get("default");
+            assertNotNull(cluster);
+            Component<?, ?> curatorComponent = cluster.getComponentsMap().get(ComponentId.fromString(componentId));
+            assertNotNull(curatorComponent);
+        }
+        {
+            try {
+                tester.createModel(servicesXml.apply(1), true);
+                fail("Expected exception");
+            } catch (IllegalArgumentException ignored) {}
+        }
+        {
+            String xmlWithNodes =
+                    "<?xml version='1.0' encoding='utf-8' ?>" +
+                    "<services>" +
+                    "  <container version='1.0' id='container1'>" +
+                    "     <zookeeper/>" +
+                    "     <nodes of='content1'/>" +
+                    "  </container>" +
+                    "  <content version='1.0' id='content1'>" +
+                    "     <nodes count='3'/>" +
+                    "   </content>" +
+                    "</services>";
+            try {
+                tester.createModel(xmlWithNodes, true);
+                fail("Expected exception");
+            } catch (IllegalArgumentException ignored) {}
+        }
+    }
 
     private Element generateContainerElementWithRenderer(String rendererId) {
         return DomBuilderTest.parse(
@@ -880,4 +923,5 @@ public class ContainerModelBuilderTest extends ContainerModelBuilderTestBase {
                 "  </search>",
                 "</container>");
     }
+
 }