Revert "Revert "Reapply "Create seperate bundles compiled against different ZooKeeper versions"""

14 files changed, 484 insertions, 35 deletions

diff --git a/zookeeper-server/CMakeLists.txt b/zookeeper-server/CMakeLists.txt
index 2065949abd4..2d8620f1028 100644
--- a/zookeeper-server/CMakeLists.txt
+++ b/zookeeper-server/CMakeLists.txt
@@ -1,2 +1,4 @@
 # Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-install_fat_java_artifact(zookeeper-server)
+add_subdirectory(zookeeper-server-common)
+add_subdirectory(zookeeper-server-3.4)
+add_subdirectory(zookeeper-server-3.5)
diff --git a/zookeeper-server/pom.xml b/zookeeper-server/pom.xml
index 3ccda41d1b9..fe182645681 100644
--- a/zookeeper-server/pom.xml
+++ b/zookeeper-server/pom.xml
@@ -9,48 +9,20 @@
     <relativePath>../parent/pom.xml</relativePath>
   </parent>
   <artifactId>zookeeper-server</artifactId>
-  <packaging>container-plugin</packaging>
+  <packaging>pom</packaging>
   <version>7-SNAPSHOT</version>
+  <modules>
+    <module>zookeeper-server-common</module>
+    <module>zookeeper-server-3.4</module>
+    <module>zookeeper-server-3.5</module>
+  </modules>
   <dependencies>
     <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>com.yahoo.vespa</groupId>
-      <artifactId>defaults</artifactId>
-      <version>${project.version}</version>
-      <scope>provided</scope>
-    </dependency>
-    <dependency>
       <groupId>com.yahoo.vespa</groupId>
       <artifactId>container-dev</artifactId>
       <version>${project.version}</version>
       <scope>provided</scope>
     </dependency>
-    <dependency>
-      <groupId>com.yahoo.vespa</groupId>
-      <artifactId>vespajlib</artifactId>
-      <version>${project.version}</version>
-      <scope>provided</scope>
-    </dependency>
-    <dependency>
-      <groupId>com.yahoo.vespa</groupId>
-      <artifactId>vespalog</artifactId>
-      <version>${project.version}</version>
-      <scope>provided</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.apache.zookeeper</groupId>
-      <artifactId>zookeeper</artifactId>
-    </dependency>
-    <dependency>
-      <!-- Needed to have the same version as slf4j-api -->
-      <groupId>org.slf4j</groupId>
-      <artifactId>slf4j-log4j12</artifactId>
-      <version>1.7.5</version>
-    </dependency>
   </dependencies>
   <build>
     <plugins>
diff --git a/zookeeper-server/zookeeper-server-3.4/CMakeLists.txt b/zookeeper-server/zookeeper-server-3.4/CMakeLists.txt
new file mode 100644
index 00000000000..d80b48c9093
--- /dev/null
+++ b/zookeeper-server/zookeeper-server-3.4/CMakeLists.txt
@@ -0,0 +1,2 @@
+# Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+install_fat_java_artifact(zookeeper-server-3.4)
diff --git a/zookeeper-server/zookeeper-server-3.4/pom.xml b/zookeeper-server/zookeeper-server-3.4/pom.xml
new file mode 100644
index 00000000000..fd437608b40
--- /dev/null
+++ b/zookeeper-server/zookeeper-server-3.4/pom.xml
@@ -0,0 +1,69 @@
+<?xml version="1.0"?>
+<!-- Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root. -->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>com.yahoo.vespa</groupId>
+    <artifactId>zookeeper-server</artifactId>
+    <version>7-SNAPSHOT</version>
+    <relativePath>../pom.xml</relativePath>
+  </parent>
+  <artifactId>zookeeper-server-3.4</artifactId>
+  <packaging>container-plugin</packaging>
+  <version>7-SNAPSHOT</version>
+  <dependencies>
+    <dependency>
+      <groupId>com.yahoo.vespa</groupId>
+      <artifactId>zookeeper-server-common</artifactId>
+      <version>${project.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.zookeeper</groupId>
+      <artifactId>zookeeper</artifactId>
+      <version>3.4.14</version>
+    </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <compilerArgs>
+            <arg>-Xlint:all</arg>
+            <arg>-Werror</arg>
+          </compilerArgs>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <configuration>
+          <redirectTestOutputToFile>${test.hide}</redirectTestOutputToFile>
+          <forkMode>once</forkMode>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-install-plugin</artifactId>
+        <configuration>
+          <updateReleaseInfo>true</updateReleaseInfo>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>com.yahoo.vespa</groupId>
+        <artifactId>bundle-plugin</artifactId>
+        <extensions>true</extensions>
+        <configuration>
+          <importPackage>com.sun.management</importPackage>
+          <bundleSymbolicName>zookeeper-server</bundleSymbolicName>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>
diff --git a/zookeeper-server/src/main/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImpl.java b/zookeeper-server/zookeeper-server-3.4/src/main/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImpl.java
index 5b4c0c11e80..5b4c0c11e80 100644
--- a/zookeeper-server/src/main/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImpl.java
+++ b/zookeeper-server/zookeeper-server-3.4/src/main/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImpl.java
diff --git a/zookeeper-server/src/test/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImplTest.java b/zookeeper-server/zookeeper-server-3.4/src/test/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImplTest.java
index 1081c5fda61..1081c5fda61 100644
--- a/zookeeper-server/src/test/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImplTest.java
+++ b/zookeeper-server/zookeeper-server-3.4/src/test/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImplTest.java
diff --git a/zookeeper-server/zookeeper-server-3.5/CMakeLists.txt b/zookeeper-server/zookeeper-server-3.5/CMakeLists.txt
new file mode 100644
index 00000000000..6094573ee24
--- /dev/null
+++ b/zookeeper-server/zookeeper-server-3.5/CMakeLists.txt
@@ -0,0 +1,2 @@
+# Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+install_fat_java_artifact(zookeeper-server-3.5)
diff --git a/zookeeper-server/zookeeper-server-3.5/pom.xml b/zookeeper-server/zookeeper-server-3.5/pom.xml
new file mode 100644
index 00000000000..fd83c62a3e3
--- /dev/null
+++ b/zookeeper-server/zookeeper-server-3.5/pom.xml
@@ -0,0 +1,69 @@
+<?xml version="1.0"?>
+<!-- Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root. -->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>com.yahoo.vespa</groupId>
+    <artifactId>zookeeper-server</artifactId>
+    <version>7-SNAPSHOT</version>
+    <relativePath>../pom.xml</relativePath>
+  </parent>
+  <artifactId>zookeeper-server-3.5</artifactId>
+  <packaging>container-plugin</packaging>
+  <version>7-SNAPSHOT</version>
+  <dependencies>
+    <dependency>
+      <groupId>com.yahoo.vespa</groupId>
+      <artifactId>zookeeper-server-common</artifactId>
+      <version>${project.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.zookeeper</groupId>
+      <artifactId>zookeeper</artifactId>
+      <version>3.5.6</version>
+    </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <compilerArgs>
+            <arg>-Xlint:all</arg>
+            <arg>-Werror</arg>
+          </compilerArgs>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <configuration>
+          <redirectTestOutputToFile>${test.hide}</redirectTestOutputToFile>
+          <forkMode>once</forkMode>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-install-plugin</artifactId>
+        <configuration>
+          <updateReleaseInfo>true</updateReleaseInfo>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>com.yahoo.vespa</groupId>
+        <artifactId>bundle-plugin</artifactId>
+        <extensions>true</extensions>
+        <configuration>
+          <importPackage>com.sun.management</importPackage>
+          <bundleSymbolicName>zookeeper-server</bundleSymbolicName>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>
diff --git a/zookeeper-server/zookeeper-server-3.5/src/main/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImpl.java b/zookeeper-server/zookeeper-server-3.5/src/main/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImpl.java
new file mode 100644
index 00000000000..9cb87efa3c0
--- /dev/null
+++ b/zookeeper-server/zookeeper-server-3.5/src/main/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImpl.java
@@ -0,0 +1,135 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.zookeeper;
+
+import com.google.inject.Inject;
+import com.yahoo.cloud.config.ZookeeperServerConfig;
+import com.yahoo.component.AbstractComponent;
+import com.yahoo.log.LogLevel;
+import static com.yahoo.vespa.defaults.Defaults.getDefaults;
+
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/**
+ * Writes zookeeper config and starts zookeeper server.
+ *
+ * @author Ulf Lilleengen
+ * @author Harald Musum
+ */
+public class VespaZooKeeperServerImpl extends AbstractComponent implements Runnable, VespaZooKeeperServer {
+
+    private static final java.util.logging.Logger log = java.util.logging.Logger.getLogger(VespaZooKeeperServerImpl.class.getName());
+    private static final String ZOOKEEPER_JMX_LOG4J_DISABLE = "zookeeper.jmx.log4j.disable";
+    static final String ZOOKEEPER_JUTE_MAX_BUFFER = "jute.maxbuffer";
+    private final Thread zkServerThread;
+    private final ZookeeperServerConfig zookeeperServerConfig;
+
+    VespaZooKeeperServerImpl(ZookeeperServerConfig zookeeperServerConfig, boolean startServer) {
+        this.zookeeperServerConfig = zookeeperServerConfig;
+        System.setProperty("zookeeper.jmx.log4j.disable", "true");
+        System.setProperty("zookeeper.snapshot.trust.empty", Boolean.valueOf(zookeeperServerConfig.trustEmptySnapshot()).toString());
+        System.setProperty(ZOOKEEPER_JUTE_MAX_BUFFER, Integer.valueOf(zookeeperServerConfig.juteMaxBuffer()).toString());
+
+        writeConfigToDisk(zookeeperServerConfig);
+        zkServerThread = new Thread(this, "zookeeper server");
+        if (startServer) {
+            zkServerThread.start();
+        }
+    }
+
+    @Inject
+    public VespaZooKeeperServerImpl(ZookeeperServerConfig zookeeperServerConfig) {
+        this(zookeeperServerConfig, true);
+    }
+
+    private void writeConfigToDisk(ZookeeperServerConfig config) {
+       String configFilePath = getDefaults().underVespaHome(config.zooKeeperConfigFile());
+       new File(configFilePath).getParentFile().mkdirs();
+       try (FileWriter writer = new FileWriter(configFilePath)) {
+           writer.write(transformConfigToString(config));
+           writeMyIdFile(config);
+       } catch (IOException e) {
+           throw new RuntimeException("Error writing zookeeper config", e);
+       }
+   }
+
+    private String transformConfigToString(ZookeeperServerConfig config) {
+        StringBuilder sb = new StringBuilder();
+        sb.append("tickTime=").append(config.tickTime()).append("\n");
+        sb.append("initLimit=").append(config.initLimit()).append("\n");
+        sb.append("syncLimit=").append(config.syncLimit()).append("\n");
+        sb.append("maxClientCnxns=").append(config.maxClientConnections()).append("\n");
+        sb.append("snapCount=").append(config.snapshotCount()).append("\n");
+        sb.append("dataDir=").append(getDefaults().underVespaHome(config.dataDir())).append("\n");
+        sb.append("clientPort=").append(config.clientPort()).append("\n");
+        sb.append("autopurge.purgeInterval=").append(config.autopurge().purgeInterval()).append("\n");
+        sb.append("autopurge.snapRetainCount=").append(config.autopurge().snapRetainCount()).append("\n");
+        // See http://zookeeper.apache.org/doc/r3.5.5/zookeeperAdmin.html#sc_zkCommands
+        // Includes all available commands in 3.5, except 'wchc' and 'wchp'
+        sb.append("4lw.commands.whitelist=conf,cons,crst,dirs,dump,envi,mntr,ruok,srst,srvr,stat,wchs").append("\n");
+        sb.append("admin.enableServer=false").append("\n");
+        // Need NettyServerCnxnFactory to be able to use TLS for communication
+        sb.append("serverCnxnFactory=org.apache.zookeeper.server.NettyServerCnxnFactory").append("\n");
+        ensureThisServerIsRepresented(config.myid(), config.server());
+        config.server().forEach(server -> addServerToCfg(sb, server));
+        return sb.toString();
+    }
+
+    private void writeMyIdFile(ZookeeperServerConfig config) throws IOException {
+        if (config.server().size() > 1) {
+            try (FileWriter writer = new FileWriter(getDefaults().underVespaHome(config.myidFile()))) {
+                writer.write(config.myid() + "\n");
+            }
+        }
+    }
+
+    private void ensureThisServerIsRepresented(int myid, List<ZookeeperServerConfig.Server> servers) {
+        boolean found = false;
+        for (ZookeeperServerConfig.Server server : servers) {
+            if (myid == server.id()) {
+                found = true;
+                break;
+            }
+        }
+        if (!found) {
+            throw new RuntimeException("No id in zookeeper server list that corresponds to my id(" + myid + ")");
+        }
+    }
+
+    private void addServerToCfg(StringBuilder sb, ZookeeperServerConfig.Server server) {
+        sb.append("server.").append(server.id()).append("=").append(server.hostname()).append(":").append(server.quorumPort()).append(":").append(server.electionPort()).append("\n");
+    }
+
+    private void shutdown() {
+        zkServerThread.interrupt();
+        try {
+            zkServerThread.join();
+        } catch (InterruptedException e) {
+            log.log(LogLevel.WARNING, "Error joining server thread on shutdown", e);
+        }
+    }
+
+    @Override
+    public void run() {
+        System.setProperty(ZOOKEEPER_JMX_LOG4J_DISABLE, "true");
+        String[] args = new String[]{getDefaults().underVespaHome(zookeeperServerConfig.zooKeeperConfigFile())};
+        log.log(LogLevel.INFO, "Starting ZooKeeper server with config file " + args[0] +
+                ". Trying to establish ZooKeeper quorum (members: " + zookeeperServerHostnames(zookeeperServerConfig) + ")");
+        org.apache.zookeeper.server.quorum.QuorumPeerMain.main(args);
+    }
+
+    @Override
+    public void deconstruct() {
+        shutdown();
+        super.deconstruct();
+    }
+
+    private static Set<String> zookeeperServerHostnames(ZookeeperServerConfig zookeeperServerConfig) {
+        return zookeeperServerConfig.server().stream().map(ZookeeperServerConfig.Server::hostname).collect(Collectors.toSet());
+    }
+
+}
diff --git a/zookeeper-server/zookeeper-server-3.5/src/test/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImplTest.java b/zookeeper-server/zookeeper-server-3.5/src/test/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImplTest.java
new file mode 100644
index 00000000000..19690bff963
--- /dev/null
+++ b/zookeeper-server/zookeeper-server-3.5/src/test/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServerImplTest.java
@@ -0,0 +1,144 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.zookeeper;
+
+import com.yahoo.cloud.config.ZookeeperServerConfig;
+import com.yahoo.io.IOUtils;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import java.io.File;
+import java.io.IOException;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+import static com.yahoo.vespa.defaults.Defaults.getDefaults;
+
+/**
+ * Tests the zookeeper server.
+ */
+public class VespaZooKeeperServerImplTest {
+
+    @Rule
+    public TemporaryFolder folder = new TemporaryFolder();
+
+    @Test
+    public void config_is_written_correctly_when_one_server() throws IOException {
+        File cfgFile = folder.newFile();
+        File idFile = folder.newFile();
+        ZookeeperServerConfig.Builder builder = new ZookeeperServerConfig.Builder();
+        builder.zooKeeperConfigFile(cfgFile.getAbsolutePath());
+        builder.myidFile(idFile.getAbsolutePath());
+        builder.server(newServer(0, "foo", 123, 321));
+        builder.myid(0);
+        createServer(builder);
+        validateConfigFileSingleHost(cfgFile);
+        validateIdFile(idFile, "");
+    }
+
+    @Test
+    public void config_is_written_correctly_when_multiple_servers() throws IOException {
+        File cfgFile = folder.newFile();
+        File idFile = folder.newFile();
+        ZookeeperServerConfig.Builder builder = new ZookeeperServerConfig.Builder();
+        builder.zooKeeperConfigFile(cfgFile.getAbsolutePath());
+        builder.server(newServer(0, "foo", 123, 321));
+        builder.server(newServer(1, "bar", 234, 432));
+        builder.server(newServer(2, "baz", 345, 543));
+        builder.myidFile(idFile.getAbsolutePath());
+        builder.myid(1);
+        createServer(builder);
+        validateConfigFileMultipleHosts(cfgFile);
+        validateIdFile(idFile, "1\n");
+    }
+
+    private void createServer(ZookeeperServerConfig.Builder builder) {
+        new VespaZooKeeperServerImpl(new ZookeeperServerConfig(builder), false);
+    }
+
+    @Test(expected = RuntimeException.class)
+    public void require_that_this_id_must_be_present_amongst_servers() {
+        ZookeeperServerConfig.Builder builder = new ZookeeperServerConfig.Builder();
+        builder.server(newServer(1, "bar", 234, 432));
+        builder.server(newServer(2, "baz", 345, 543));
+        builder.myid(0);
+        createServer(builder);
+    }
+
+    @Test
+    public void juteMaxBufferCanBeSet() throws IOException {
+        ZookeeperServerConfig.Builder builder = new ZookeeperServerConfig.Builder();
+        builder.myid(0);
+        File idFile = folder.newFile();
+        File cfgFile = folder.newFile();
+
+        builder.server(new ZookeeperServerConfig.Server.Builder().id(0).hostname("testhost"));
+        builder.zooKeeperConfigFile(cfgFile.getAbsolutePath());
+        builder.myidFile(idFile.getAbsolutePath());
+
+        createServer(builder);
+        assertThat(System.getProperty(VespaZooKeeperServerImpl.ZOOKEEPER_JUTE_MAX_BUFFER), is("" + new ZookeeperServerConfig(builder).juteMaxBuffer()));
+
+        final int max_buffer = 1;
+        builder.juteMaxBuffer(max_buffer);
+        createServer(builder);
+        assertThat(System.getProperty(VespaZooKeeperServerImpl.ZOOKEEPER_JUTE_MAX_BUFFER), is("" + max_buffer));
+    }
+
+    private ZookeeperServerConfig.Server.Builder newServer(int id, String hostName, int electionPort, int quorumPort) {
+        ZookeeperServerConfig.Server.Builder builder = new ZookeeperServerConfig.Server.Builder();
+        builder.id(id);
+        builder.hostname(hostName);
+        builder.electionPort(electionPort);
+        builder.quorumPort(quorumPort);
+        return builder;
+    }
+
+    private void validateIdFile(File idFile, String expected) throws IOException {
+        String actual = IOUtils.readFile(idFile);
+        assertThat(actual, is(expected));
+    }
+
+    private void validateConfigFileSingleHost(File cfgFile) throws IOException {
+        String expected =
+            "tickTime=2000\n" +
+            "initLimit=20\n" +
+            "syncLimit=15\n" +
+            "maxClientCnxns=0\n" +
+            "snapCount=50000\n" +
+            "dataDir=" + getDefaults().underVespaHome("var/zookeeper") + "\n" +
+            "clientPort=2181\n" +
+            "autopurge.purgeInterval=1\n" +
+            "autopurge.snapRetainCount=15\n" +
+            "4lw.commands.whitelist=conf,cons,crst,dirs,dump,envi,mntr,ruok,srst,srvr,stat,wchs\n" +
+            "admin.enableServer=false\n" +
+            "serverCnxnFactory=org.apache.zookeeper.server.NettyServerCnxnFactory\n" +
+            "server.0=foo:321:123\n";
+        validateConfigFile(cfgFile, expected);
+    }
+
+    private void validateConfigFileMultipleHosts(File cfgFile) throws IOException {
+        String expected =
+                "tickTime=2000\n" +
+                        "initLimit=20\n" +
+                        "syncLimit=15\n" +
+                        "maxClientCnxns=0\n" +
+                        "snapCount=50000\n" +
+                        "dataDir=" + getDefaults().underVespaHome("var/zookeeper") + "\n" +
+                        "clientPort=2181\n" +
+                        "autopurge.purgeInterval=1\n" +
+                        "autopurge.snapRetainCount=15\n" +
+                        "4lw.commands.whitelist=conf,cons,crst,dirs,dump,envi,mntr,ruok,srst,srvr,stat,wchs\n" +
+                        "admin.enableServer=false\n" +
+                        "serverCnxnFactory=org.apache.zookeeper.server.NettyServerCnxnFactory\n" +
+                        "server.0=foo:321:123\n" +
+                        "server.1=bar:432:234\n" +
+                        "server.2=baz:543:345\n";
+        validateConfigFile(cfgFile, expected);
+    }
+
+    private void validateConfigFile(File cfgFile, String expected) throws IOException {
+        String actual = IOUtils.readFile(cfgFile);
+        assertThat(actual, is(expected));
+    }
+}
diff --git a/zookeeper-server/zookeeper-server-common/CMakeLists.txt b/zookeeper-server/zookeeper-server-common/CMakeLists.txt
new file mode 100644
index 00000000000..fd467aca067
--- /dev/null
+++ b/zookeeper-server/zookeeper-server-common/CMakeLists.txt
@@ -0,0 +1,2 @@
+# Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+install_fat_java_artifact(zookeeper-server-common)
diff --git a/zookeeper-server/zookeeper-server-common/pom.xml b/zookeeper-server/zookeeper-server-common/pom.xml
new file mode 100644
index 00000000000..66e5bc2075c
--- /dev/null
+++ b/zookeeper-server/zookeeper-server-common/pom.xml
@@ -0,0 +1,52 @@
+<?xml version="1.0"?>
+<!-- Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root. -->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>com.yahoo.vespa</groupId>
+    <artifactId>zookeeper-server</artifactId>
+    <version>7-SNAPSHOT</version>
+    <relativePath>../pom.xml</relativePath>
+  </parent>
+  <artifactId>zookeeper-server-common</artifactId>
+  <packaging>container-plugin</packaging>
+  <version>7-SNAPSHOT</version>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <compilerArgs>
+            <arg>-Xlint:all</arg>
+            <arg>-Werror</arg>
+          </compilerArgs>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <configuration>
+          <redirectTestOutputToFile>${test.hide}</redirectTestOutputToFile>
+          <forkMode>once</forkMode>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-install-plugin</artifactId>
+        <configuration>
+          <updateReleaseInfo>true</updateReleaseInfo>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>com.yahoo.vespa</groupId>
+        <artifactId>bundle-plugin</artifactId>
+        <extensions>true</extensions>
+        <configuration>
+          <importPackage>com.sun.management</importPackage>
+          <bundleSymbolicName>zookeeper-server</bundleSymbolicName>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>
diff --git a/zookeeper-server/src/main/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServer.java b/zookeeper-server/zookeeper-server-common/src/main/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServer.java
index 5a1f31a75c3..5a1f31a75c3 100644
--- a/zookeeper-server/src/main/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServer.java
+++ b/zookeeper-server/zookeeper-server-common/src/main/java/com/yahoo/vespa/zookeeper/VespaZooKeeperServer.java
diff --git a/zookeeper-server/src/main/java/com/yahoo/vespa/zookeeper/package-info.java b/zookeeper-server/zookeeper-server-common/src/main/java/com/yahoo/vespa/zookeeper/package-info.java
index 470d1350f9c..470d1350f9c 100644
--- a/zookeeper-server/src/main/java/com/yahoo/vespa/zookeeper/package-info.java
+++ b/zookeeper-server/zookeeper-server-common/src/main/java/com/yahoo/vespa/zookeeper/package-info.java