Make ZooKeeperClient inner class of the only class that uses it

6 files changed, 449 insertions, 479 deletions

diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClient.java b/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClient.java
deleted file mode 100644
index efa62625159..00000000000
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClient.java
+++ /dev/null
@@ -1,281 +0,0 @@
-// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.vespa.config.server.deploy;
-
-import com.yahoo.component.Version;
-import com.yahoo.config.application.api.ApplicationFile;
-import com.yahoo.config.application.api.ApplicationMetaData;
-import com.yahoo.config.application.api.ApplicationPackage;
-import com.yahoo.config.application.api.DeployLogger;
-import com.yahoo.config.application.api.FileRegistry;
-import com.yahoo.config.application.api.UnparsedConfigDefinition;
-import com.yahoo.config.provision.AllocatedHosts;
-import com.yahoo.config.provision.serialization.AllocatedHostsSerializer;
-import com.yahoo.io.reader.NamedReader;
-import com.yahoo.path.Path;
-import com.yahoo.text.Utf8;
-import com.yahoo.vespa.config.ConfigDefinitionKey;
-import com.yahoo.vespa.config.server.filedistribution.FileDBRegistry;
-import com.yahoo.vespa.config.server.zookeeper.ZKApplicationPackage;
-import com.yahoo.vespa.curator.Curator;
-import com.yahoo.yolean.Exceptions;
-
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.List;
-import java.util.Map;
-import java.util.logging.Level;
-
-import static com.yahoo.config.application.api.ApplicationPackage.*;
-import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.DEFCONFIGS_ZK_SUBPATH;
-import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.META_ZK_PATH;
-import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.USERAPP_ZK_SUBPATH;
-import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.USER_DEFCONFIGS_ZK_SUBPATH;
-
-/**
- * Reads and writes application package to and from ZooKeeper.
- *
- * @author hmusum
- */
-public class ZooKeeperClient {
-
-    private final Curator curator;
-    private final DeployLogger logger;
-    private final Path sessionPath; // session id
-
-    private static final ApplicationFile.PathFilter xmlFilter = path -> path.getName().endsWith(".xml");
-
-    public ZooKeeperClient(Curator curator, DeployLogger logger, Path sessionPath) {
-        this.curator = curator;
-        this.logger = logger;
-        this.sessionPath = sessionPath;
-    }
-
-    /**
-     * Sets up basic node structure in ZooKeeper and purges old data.
-     * This is the first operation on ZK during deploy.
-     */
-    void initialize() {
-        curator.create(sessionPath);
-
-        for (String subPath : Arrays.asList(DEFCONFIGS_ZK_SUBPATH,
-                                            USER_DEFCONFIGS_ZK_SUBPATH,
-                                            USERAPP_ZK_SUBPATH,
-                                            ZKApplicationPackage.fileRegistryNode)) {
-            // TODO: The replaceFirst below is hackish.
-            curator.create(getZooKeeperAppPath().append(subPath.replaceFirst("/", "")));
-        }
-    }
-
-    /**
-     * Writes def files and user config into ZK.
-     *
-     * @param app the application package to feed to zookeeper
-     */
-    void writeApplicationPackage(ApplicationPackage app) {
-        try {
-            writeUserDefs(app);
-            writeSomeOf(app);
-            writeSchemas(app);
-            writeUserIncludeDirs(app, app.getUserIncludeDirs());
-            writeMetadata(app.getMetaData());
-        } catch (Exception e) {
-            throw new IllegalStateException("Unable to write vespa model to config server(s) " + System.getProperty("configsources") + "\n" +
-                                            "Please ensure that config server is started " +
-                                            "and check the vespa log for configserver errors. ", e);
-        }
-    }
-
-    private void writeSchemas(ApplicationPackage app) throws IOException {
-        Collection<NamedReader> schemas = app.getSchemas();
-        if (schemas.isEmpty()) return;
-
-        Path zkPath = getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(SCHEMAS_DIR);
-        curator.create(zkPath);
-        // Ensures that ranking expressions and other files are also written
-        writeDir(app.getFile(ApplicationPackage.SEARCH_DEFINITIONS_DIR), zkPath);
-        writeDir(app.getFile(ApplicationPackage.SCHEMAS_DIR), zkPath);
-        for (NamedReader sd : schemas) {
-            curator.set(zkPath.append(sd.getName()), Utf8.toBytes(com.yahoo.io.IOUtils.readAll(sd.getReader())));
-            sd.getReader().close();
-        }
-    }
-
-    /**
-     * Writes some application package files into ZK - see write(app).
-     *
-     * @param app the application package to use as input.
-     * @throws java.io.IOException if not able to write to Zookeeper
-     */
-    private void writeSomeOf(ApplicationPackage app) throws IOException {
-        // TODO: We should have a way of doing this which doesn't require repeating all the content
-        writeFile(app.getFile(Path.fromString(SERVICES)), getZooKeeperAppPath(USERAPP_ZK_SUBPATH));
-        writeFile(app.getFile(Path.fromString(HOSTS)), getZooKeeperAppPath(USERAPP_ZK_SUBPATH));
-        writeFile(app.getFile(Path.fromString(DEPLOYMENT_FILE.getName())), getZooKeeperAppPath(USERAPP_ZK_SUBPATH));
-        writeFile(app.getFile(Path.fromString(VALIDATION_OVERRIDES.getName())), getZooKeeperAppPath(USERAPP_ZK_SUBPATH));
-        writeDir(app.getFile(RULES_DIR),
-                 getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(RULES_DIR),
-                 (path) -> path.getName().endsWith(ApplicationPackage.RULES_NAME_SUFFIX));
-        writeDir(app.getFile(QUERY_PROFILES_DIR),
-                 getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(QUERY_PROFILES_DIR),
-                 xmlFilter);
-        writeDir(app.getFile(PAGE_TEMPLATES_DIR),
-                 getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(PAGE_TEMPLATES_DIR),
-                 xmlFilter);
-        writeDir(app.getFile(Path.fromString(SEARCHCHAINS_DIR)),
-                 getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(SEARCHCHAINS_DIR),
-                 xmlFilter);
-        writeDir(app.getFile(Path.fromString(DOCPROCCHAINS_DIR)),
-                 getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(DOCPROCCHAINS_DIR),
-                 xmlFilter);
-        writeDir(app.getFile(Path.fromString(ROUTINGTABLES_DIR)),
-                 getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(ROUTINGTABLES_DIR),
-                 xmlFilter);
-        writeDir(app.getFile(MODELS_GENERATED_REPLICATED_DIR),
-                 getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(MODELS_GENERATED_REPLICATED_DIR));
-        writeDir(app.getFile(SECURITY_DIR),
-                 getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(SECURITY_DIR));
-    }
-
-    private void writeDir(ApplicationFile file, Path zooKeeperAppPath) throws IOException {
-        writeDir(file, zooKeeperAppPath, (__) -> true);
-    }
-
-    private void writeDir(ApplicationFile dir, Path path, ApplicationFile.PathFilter filenameFilter) throws IOException {
-        if ( ! dir.isDirectory()) return;
-        for (ApplicationFile file : listFiles(dir, filenameFilter)) {
-            String name = file.getPath().getName();
-            if (name.startsWith(".")) continue; //.svn , .git ...
-            if (file.isDirectory()) {
-                curator.create(path.append(name));
-                writeDir(file, path.append(name), filenameFilter);
-            } else {
-                writeFile(file, path);
-            }
-        }
-    }
-
-    /**
-     * Like {@link ApplicationFile#listFiles(com.yahoo.config.application.api.ApplicationFile.PathFilter)}
-     * with slightly different semantics: Never filter out directories.
-     */
-    private List<ApplicationFile> listFiles(ApplicationFile dir, ApplicationFile.PathFilter filter) {
-        List<ApplicationFile> rawList = dir.listFiles();
-        List<ApplicationFile> ret = new ArrayList<>();
-        if (rawList != null) {
-            for (ApplicationFile f : rawList) {
-                if (f.isDirectory()) {
-                    ret.add(f);
-                } else {
-                    if (filter.accept(f.getPath())) {
-                        ret.add(f);
-                    }
-                }
-            }
-        }
-        return ret;
-    }
-
-    private void writeFile(ApplicationFile file, Path zkPath) throws IOException {
-        if ( ! file.exists()) return;
-
-        ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        try (InputStream inputStream = file.createInputStream()) {
-            inputStream.transferTo(baos);
-            baos.flush();
-            curator.set(zkPath.append(file.getPath().getName()), baos.toByteArray());
-        }
-    }
-
-    private void writeUserIncludeDirs(ApplicationPackage applicationPackage, List<String> userIncludeDirs) throws IOException {
-        for (String userInclude : userIncludeDirs) {
-            ApplicationFile dir = applicationPackage.getFile(Path.fromString(userInclude));
-            final List<ApplicationFile> files = dir.listFiles();
-            if (files == null || files.isEmpty()) {
-                curator.create(getZooKeeperAppPath(USERAPP_ZK_SUBPATH + "/" + userInclude));
-            }
-            writeDir(dir, getZooKeeperAppPath(USERAPP_ZK_SUBPATH + "/" + userInclude), xmlFilter);
-        }
-    }
-
-    /**
-     * Feeds all user-defined .def file from the application package into ZooKeeper (both into
-     * /defconfigs and /userdefconfigs
-     */
-    private void writeUserDefs(ApplicationPackage applicationPackage) {
-        Map<ConfigDefinitionKey, UnparsedConfigDefinition> configDefs = applicationPackage.getAllExistingConfigDefs();
-        for (Map.Entry<ConfigDefinitionKey, UnparsedConfigDefinition> entry : configDefs.entrySet()) {
-            ConfigDefinitionKey key = entry.getKey();
-            String contents = entry.getValue().getUnparsedContent();
-            writeConfigDefinition(key.getName(), key.getNamespace(), getZooKeeperAppPath(USER_DEFCONFIGS_ZK_SUBPATH), contents);
-            writeConfigDefinition(key.getName(), key.getNamespace(), getZooKeeperAppPath(DEFCONFIGS_ZK_SUBPATH), contents);
-        }
-        logger.log(Level.FINE, configDefs.size() + " user config definitions");
-    }
-
-    private void writeConfigDefinition(String name, String namespace, Path path, String data) {
-        curator.set(path.append(namespace + "." + name), Utf8.toBytes(data));
-    }
-
-    private void write(Version vespaVersion, FileRegistry fileRegistry) {
-        String exportedRegistry = FileDBRegistry.exportRegistry(fileRegistry);
-        curator.set(getZooKeeperAppPath(ZKApplicationPackage.fileRegistryNode).append(vespaVersion.toFullString()),
-                    Utf8.toBytes(exportedRegistry));
-    }
-
-    /**
-     * Feeds application metadata to zookeeper. Used by config model to create config
-     * for application metadata
-     *
-     * @param metaData The application metadata.
-     */
-    private void writeMetadata(ApplicationMetaData metaData) {
-        curator.set(getZooKeeperAppPath(META_ZK_PATH), metaData.asJsonBytes());
-    }
-
-    void cleanupZooKeeper() {
-        try {
-            List.of(DEFCONFIGS_ZK_SUBPATH, USER_DEFCONFIGS_ZK_SUBPATH, USERAPP_ZK_SUBPATH)
-                .forEach(path -> curator.delete(getZooKeeperAppPath(path)));
-        } catch (Exception e) {
-            logger.log(Level.WARNING, "Could not clean up in zookeeper: " + Exceptions.toMessageString(e));
-            // Might be called in an exception handler before re-throw, so do not throw here.
-        }
-    }
-
-    /**
-     * Gets a full ZK application path
-     *
-     * @return a String with the full ZK application path
-     */
-    private Path getZooKeeperAppPath() {
-        return getZooKeeperAppPath(null);
-    }
-
-    /**
-     * Gets a full ZK application path
-     *
-     * @param trailingPath trailing part of path to be appended to ZK app path
-     * @return a String with the full ZK application path including trailing path, if set
-     */
-    private Path getZooKeeperAppPath(String trailingPath) {
-        if (trailingPath == null) return sessionPath;
-
-        return sessionPath.append(trailingPath);
-    }
-
-    public void write(AllocatedHosts hosts) throws IOException {
-        curator.set(sessionPath.append(ZKApplicationPackage.allocatedHostsNode),
-                    AllocatedHostsSerializer.toJson(hosts));
-    }
-
-    public void write(Map<Version, FileRegistry> fileRegistryMap) {
-        for (Map.Entry<Version, FileRegistry> versionFileRegistryEntry : fileRegistryMap.entrySet()) {
-            write(versionFileRegistryEntry.getKey(), versionFileRegistryEntry.getValue());
-        }
-    }
-
-}
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ZooKeeperDeployer.java b/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ZooKeeperDeployer.java
index 8d889b1fb2c..cb50bd54d38 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ZooKeeperDeployer.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ZooKeeperDeployer.java
@@ -1,13 +1,53 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config.server.deploy;
 
+import com.yahoo.config.application.api.ApplicationFile;
+import com.yahoo.config.application.api.ApplicationMetaData;
 import com.yahoo.config.application.api.ApplicationPackage;
+import com.yahoo.config.application.api.DeployLogger;
 import com.yahoo.config.application.api.FileRegistry;
+import com.yahoo.config.application.api.UnparsedConfigDefinition;
 import com.yahoo.config.provision.AllocatedHosts;
 import com.yahoo.component.Version;
+import com.yahoo.config.provision.ApplicationId;
+import com.yahoo.config.provision.serialization.AllocatedHostsSerializer;
+import com.yahoo.io.reader.NamedReader;
+import com.yahoo.path.Path;
+import com.yahoo.text.Utf8;
+import com.yahoo.vespa.config.ConfigDefinitionKey;
+import com.yahoo.vespa.config.server.filedistribution.FileDBRegistry;
+import com.yahoo.vespa.config.server.zookeeper.ZKApplicationPackage;
+import com.yahoo.vespa.curator.Curator;
+import com.yahoo.yolean.Exceptions;
 
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
 import java.util.Map;
+import java.util.logging.Level;
+
+import static com.yahoo.config.application.api.ApplicationPackage.DEPLOYMENT_FILE;
+import static com.yahoo.config.application.api.ApplicationPackage.DOCPROCCHAINS_DIR;
+import static com.yahoo.config.application.api.ApplicationPackage.HOSTS;
+import static com.yahoo.config.application.api.ApplicationPackage.MODELS_GENERATED_REPLICATED_DIR;
+import static com.yahoo.config.application.api.ApplicationPackage.PAGE_TEMPLATES_DIR;
+import static com.yahoo.config.application.api.ApplicationPackage.QUERY_PROFILES_DIR;
+import static com.yahoo.config.application.api.ApplicationPackage.ROUTINGTABLES_DIR;
+import static com.yahoo.config.application.api.ApplicationPackage.RULES_DIR;
+import static com.yahoo.config.application.api.ApplicationPackage.SCHEMAS_DIR;
+import static com.yahoo.config.application.api.ApplicationPackage.SEARCHCHAINS_DIR;
+import static com.yahoo.config.application.api.ApplicationPackage.SECURITY_DIR;
+import static com.yahoo.config.application.api.ApplicationPackage.SERVICES;
+import static com.yahoo.config.application.api.ApplicationPackage.VALIDATION_OVERRIDES;
+import static com.yahoo.vespa.config.server.session.SessionZooKeeperClient.getSessionPath;
+import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.DEFCONFIGS_ZK_SUBPATH;
+import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.META_ZK_PATH;
+import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.USERAPP_ZK_SUBPATH;
+import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.USER_DEFCONFIGS_ZK_SUBPATH;
 
 /**
  * Interface for initializing zookeeper and deploying an application package to zookeeper.
@@ -16,10 +56,11 @@ import java.util.Map;
  */
 public class ZooKeeperDeployer {
 
-    private final ZooKeeperClient zooKeeperClient;
+    private final Client client;
 
-    public ZooKeeperDeployer(ZooKeeperClient client) {
-        this.zooKeeperClient = client;
+    public ZooKeeperDeployer(Curator curator, DeployLogger logger, ApplicationId applicationId, long sessionId) {
+        Path sessionPath = getSessionPath(applicationId.tenant(), sessionId);
+        this.client = new Client(curator, logger, sessionPath);
     }
 
     /**
@@ -32,14 +73,259 @@ public class ZooKeeperDeployer {
      */
     public void deploy(ApplicationPackage applicationPackage, Map<Version, FileRegistry> fileRegistryMap, 
                        AllocatedHosts allocatedHosts) throws IOException {
-        zooKeeperClient.initialize();
-        zooKeeperClient.writeApplicationPackage(applicationPackage);
-        zooKeeperClient.write(fileRegistryMap);
-        zooKeeperClient.write(allocatedHosts);
+        client.initialize();
+        client.writeApplicationPackage(applicationPackage);
+        client.write(fileRegistryMap);
+        client.write(allocatedHosts);
     }
 
     public void cleanup() {
-        zooKeeperClient.cleanupZooKeeper();
+        client.cleanupZooKeeper();
+    }
+
+    /**
+     * Reads and writes application package to and from ZooKeeper.
+     *
+     * @author hmusum
+     */
+    public static class Client {
+
+        private final Curator curator;
+        private final DeployLogger logger;
+        private final Path sessionPath; // session id
+
+        private static final ApplicationFile.PathFilter xmlFilter = path -> path.getName().endsWith(".xml");
+
+        public Client(Curator curator, DeployLogger logger, Path sessionPath) {
+            this.curator = curator;
+            this.logger = logger;
+            this.sessionPath = sessionPath;
+        }
+
+        /**
+         * Sets up basic node structure in ZooKeeper and purges old data.
+         * This is the first operation on ZK during deploy.
+         */
+        void initialize() {
+            curator.create(sessionPath);
+
+            for (String subPath : Arrays.asList(DEFCONFIGS_ZK_SUBPATH,
+                                                USER_DEFCONFIGS_ZK_SUBPATH,
+                                                USERAPP_ZK_SUBPATH,
+                                                ZKApplicationPackage.fileRegistryNode)) {
+                // TODO: The replaceFirst below is hackish.
+                curator.create(getZooKeeperAppPath().append(subPath.replaceFirst("/", "")));
+            }
+        }
+
+        /**
+         * Writes def files and user config into ZK.
+         *
+         * @param app the application package to feed to zookeeper
+         */
+        void writeApplicationPackage(ApplicationPackage app) {
+            try {
+                writeUserDefs(app);
+                writeSomeOf(app);
+                writeSchemas(app);
+                writeUserIncludeDirs(app, app.getUserIncludeDirs());
+                writeMetadata(app.getMetaData());
+            } catch (Exception e) {
+                throw new IllegalStateException("Unable to write vespa model to config server(s) " + System.getProperty("configsources") + "\n" +
+                                                "Please ensure that config server is started " +
+                                                "and check the vespa log for configserver errors. ", e);
+            }
+        }
+
+        private void writeSchemas(ApplicationPackage app) throws IOException {
+            Collection<NamedReader> schemas = app.getSchemas();
+            if (schemas.isEmpty()) return;
+
+            Path zkPath = getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(SCHEMAS_DIR);
+            curator.create(zkPath);
+            // Ensures that ranking expressions and other files are also written
+            writeDir(app.getFile(ApplicationPackage.SEARCH_DEFINITIONS_DIR), zkPath);
+            writeDir(app.getFile(ApplicationPackage.SCHEMAS_DIR), zkPath);
+            for (NamedReader sd : schemas) {
+                curator.set(zkPath.append(sd.getName()), Utf8.toBytes(com.yahoo.io.IOUtils.readAll(sd.getReader())));
+                sd.getReader().close();
+            }
+        }
+
+        /**
+         * Writes some application package files into ZK - see write(app).
+         *
+         * @param app the application package to use as input.
+         * @throws IOException if not able to write to Zookeeper
+         */
+        private void writeSomeOf(ApplicationPackage app) throws IOException {
+            // TODO: We should have a way of doing this which doesn't require repeating all the content
+            writeFile(app.getFile(Path.fromString(SERVICES)), getZooKeeperAppPath(USERAPP_ZK_SUBPATH));
+            writeFile(app.getFile(Path.fromString(HOSTS)), getZooKeeperAppPath(USERAPP_ZK_SUBPATH));
+            writeFile(app.getFile(Path.fromString(DEPLOYMENT_FILE.getName())), getZooKeeperAppPath(USERAPP_ZK_SUBPATH));
+            writeFile(app.getFile(Path.fromString(VALIDATION_OVERRIDES.getName())), getZooKeeperAppPath(USERAPP_ZK_SUBPATH));
+            writeDir(app.getFile(RULES_DIR),
+                     getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(RULES_DIR),
+                     (path) -> path.getName().endsWith(ApplicationPackage.RULES_NAME_SUFFIX));
+            writeDir(app.getFile(QUERY_PROFILES_DIR),
+                     getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(QUERY_PROFILES_DIR),
+                     xmlFilter);
+            writeDir(app.getFile(PAGE_TEMPLATES_DIR),
+                     getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(PAGE_TEMPLATES_DIR),
+                     xmlFilter);
+            writeDir(app.getFile(Path.fromString(SEARCHCHAINS_DIR)),
+                     getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(SEARCHCHAINS_DIR),
+                     xmlFilter);
+            writeDir(app.getFile(Path.fromString(DOCPROCCHAINS_DIR)),
+                     getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(DOCPROCCHAINS_DIR),
+                     xmlFilter);
+            writeDir(app.getFile(Path.fromString(ROUTINGTABLES_DIR)),
+                     getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(ROUTINGTABLES_DIR),
+                     xmlFilter);
+            writeDir(app.getFile(MODELS_GENERATED_REPLICATED_DIR),
+                     getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(MODELS_GENERATED_REPLICATED_DIR));
+            writeDir(app.getFile(SECURITY_DIR),
+                     getZooKeeperAppPath(USERAPP_ZK_SUBPATH).append(SECURITY_DIR));
+        }
+
+        private void writeDir(ApplicationFile file, Path zooKeeperAppPath) throws IOException {
+            writeDir(file, zooKeeperAppPath, (__) -> true);
+        }
+
+        private void writeDir(ApplicationFile dir, Path path, ApplicationFile.PathFilter filenameFilter) throws IOException {
+            if ( ! dir.isDirectory()) return;
+            for (ApplicationFile file : listFiles(dir, filenameFilter)) {
+                String name = file.getPath().getName();
+                if (name.startsWith(".")) continue; //.svn , .git ...
+                if (file.isDirectory()) {
+                    curator.create(path.append(name));
+                    writeDir(file, path.append(name), filenameFilter);
+                } else {
+                    writeFile(file, path);
+                }
+            }
+        }
+
+        /**
+         * Like {@link ApplicationFile#listFiles(ApplicationFile.PathFilter)}
+         * with slightly different semantics: Never filter out directories.
+         */
+        private List<ApplicationFile> listFiles(ApplicationFile dir, ApplicationFile.PathFilter filter) {
+            List<ApplicationFile> rawList = dir.listFiles();
+            List<ApplicationFile> ret = new ArrayList<>();
+            if (rawList != null) {
+                for (ApplicationFile f : rawList) {
+                    if (f.isDirectory()) {
+                        ret.add(f);
+                    } else {
+                        if (filter.accept(f.getPath())) {
+                            ret.add(f);
+                        }
+                    }
+                }
+            }
+            return ret;
+        }
+
+        private void writeFile(ApplicationFile file, Path zkPath) throws IOException {
+            if ( ! file.exists()) return;
+
+            ByteArrayOutputStream baos = new ByteArrayOutputStream();
+            try (InputStream inputStream = file.createInputStream()) {
+                inputStream.transferTo(baos);
+                baos.flush();
+                curator.set(zkPath.append(file.getPath().getName()), baos.toByteArray());
+            }
+        }
+
+        private void writeUserIncludeDirs(ApplicationPackage applicationPackage, List<String> userIncludeDirs) throws IOException {
+            for (String userInclude : userIncludeDirs) {
+                ApplicationFile dir = applicationPackage.getFile(Path.fromString(userInclude));
+                final List<ApplicationFile> files = dir.listFiles();
+                if (files == null || files.isEmpty()) {
+                    curator.create(getZooKeeperAppPath(USERAPP_ZK_SUBPATH + "/" + userInclude));
+                }
+                writeDir(dir, getZooKeeperAppPath(USERAPP_ZK_SUBPATH + "/" + userInclude), xmlFilter);
+            }
+        }
+
+        /**
+         * Feeds all user-defined .def file from the application package into ZooKeeper (both into
+         * /defconfigs and /userdefconfigs
+         */
+        private void writeUserDefs(ApplicationPackage applicationPackage) {
+            Map<ConfigDefinitionKey, UnparsedConfigDefinition> configDefs = applicationPackage.getAllExistingConfigDefs();
+            for (Map.Entry<ConfigDefinitionKey, UnparsedConfigDefinition> entry : configDefs.entrySet()) {
+                ConfigDefinitionKey key = entry.getKey();
+                String contents = entry.getValue().getUnparsedContent();
+                writeConfigDefinition(key.getName(), key.getNamespace(), getZooKeeperAppPath(USER_DEFCONFIGS_ZK_SUBPATH), contents);
+                writeConfigDefinition(key.getName(), key.getNamespace(), getZooKeeperAppPath(DEFCONFIGS_ZK_SUBPATH), contents);
+            }
+            logger.log(Level.FINE, configDefs.size() + " user config definitions");
+        }
+
+        private void writeConfigDefinition(String name, String namespace, Path path, String data) {
+            curator.set(path.append(namespace + "." + name), Utf8.toBytes(data));
+        }
+
+        private void write(Version vespaVersion, FileRegistry fileRegistry) {
+            String exportedRegistry = FileDBRegistry.exportRegistry(fileRegistry);
+            curator.set(getZooKeeperAppPath(ZKApplicationPackage.fileRegistryNode).append(vespaVersion.toFullString()),
+                        Utf8.toBytes(exportedRegistry));
+        }
+
+        /**
+         * Feeds application metadata to zookeeper. Used by config model to create config
+         * for application metadata
+         *
+         * @param metaData The application metadata.
+         */
+        private void writeMetadata(ApplicationMetaData metaData) {
+            curator.set(getZooKeeperAppPath(META_ZK_PATH), metaData.asJsonBytes());
+        }
+
+        void cleanupZooKeeper() {
+            try {
+                List.of(DEFCONFIGS_ZK_SUBPATH, USER_DEFCONFIGS_ZK_SUBPATH, USERAPP_ZK_SUBPATH)
+                    .forEach(path -> curator.delete(getZooKeeperAppPath(path)));
+            } catch (Exception e) {
+                logger.log(Level.WARNING, "Could not clean up in zookeeper: " + Exceptions.toMessageString(e));
+                // Might be called in an exception handler before re-throw, so do not throw here.
+            }
+        }
+
+        /**
+         * Gets a full ZK application path
+         *
+         * @return a String with the full ZK application path
+         */
+        private Path getZooKeeperAppPath() {
+            return getZooKeeperAppPath(null);
+        }
+
+        /**
+         * Gets a full ZK application path
+         *
+         * @param trailingPath trailing part of path to be appended to ZK app path
+         * @return a String with the full ZK application path including trailing path, if set
+         */
+        private Path getZooKeeperAppPath(String trailingPath) {
+            if (trailingPath == null) return sessionPath;
+
+            return sessionPath.append(trailingPath);
+        }
+
+        public void write(AllocatedHosts hosts) throws IOException {
+            curator.set(sessionPath.append(ZKApplicationPackage.allocatedHostsNode),
+                        AllocatedHostsSerializer.toJson(hosts));
+        }
+
+        public void write(Map<Version, FileRegistry> fileRegistryMap) {
+            for (Map.Entry<Version, FileRegistry> versionFileRegistryEntry : fileRegistryMap.entrySet()) {
+                write(versionFileRegistryEntry.getKey(), versionFileRegistryEntry.getValue());
+            }
+        }
+
     }
 
 }
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionPreparer.java b/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionPreparer.java
index 8d45ac7e8f1..60b8b4d1ea8 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionPreparer.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionPreparer.java
@@ -36,7 +36,6 @@ import com.yahoo.vespa.config.server.ConfigServerSpec;
 import com.yahoo.vespa.config.server.TimeoutBudget;
 import com.yahoo.vespa.config.server.application.ApplicationSet;
 import com.yahoo.vespa.config.server.configchange.ConfigChangeActions;
-import com.yahoo.vespa.config.server.deploy.ZooKeeperClient;
 import com.yahoo.vespa.config.server.deploy.ZooKeeperDeployer;
 import com.yahoo.vespa.config.server.filedistribution.FileDistributionFactory;
 import com.yahoo.vespa.config.server.host.HostValidator;
@@ -74,8 +73,6 @@ import java.util.logging.Logger;
 import java.util.stream.Collectors;
 import java.util.zip.ZipException;
 
-import static com.yahoo.vespa.config.server.session.SessionZooKeeperClient.getSessionPath;
-
 /**
  * A SessionPreparer is responsible for preparing a session given an application package.
  *
@@ -396,10 +393,9 @@ public class SessionPreparer {
                                        List<X509Certificate> operatorCertificates,
                                        Optional<CloudAccount> cloudAccount,
                                        List<DataplaneToken> dataplaneTokens) {
-        Path sessionPath = getSessionPath(applicationId.tenant(), zooKeeperClient.sessionId());
-        ZooKeeperDeployer zkDeployer = new ZooKeeperDeployer(new ZooKeeperClient(curator, deployLogger, sessionPath));
+        var zooKeeperDeplyer = new ZooKeeperDeployer(curator, deployLogger, applicationId, zooKeeperClient.sessionId());
         try {
-            zkDeployer.deploy(applicationPackage, fileRegistryMap, allocatedHosts);
+            zooKeeperDeplyer.deploy(applicationPackage, fileRegistryMap, allocatedHosts);
             new SessionSerializer().write(zooKeeperClient,
                                           applicationId,
                                           fileReference,
@@ -413,7 +409,7 @@ public class SessionPreparer {
                                           dataplaneTokens,
                                           writeSessionData);
         } catch (RuntimeException | IOException e) {
-            zkDeployer.cleanup();
+            zooKeeperDeplyer.cleanup();
             throw new RuntimeException("Error preparing session", e);
         }
     }
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionZooKeeperClient.java b/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionZooKeeperClient.java
index 7d1a7ceae4e..04856f0b5c4 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionZooKeeperClient.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/session/SessionZooKeeperClient.java
@@ -361,7 +361,7 @@ public class SessionZooKeeperClient {
         transaction.commit();
     }
 
-    static Path getSessionPath(TenantName tenantName, long sessionId) {
+    public static Path getSessionPath(TenantName tenantName, long sessionId) {
         return TenantRepository.getSessionsPath(tenantName).append(String.valueOf(sessionId));
     }
 }
diff --git a/configserver/src/test/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClientTest.java b/configserver/src/test/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClientTest.java
deleted file mode 100644
index 2d42cb12076..00000000000
--- a/configserver/src/test/java/com/yahoo/vespa/config/server/deploy/ZooKeeperClientTest.java
+++ /dev/null
@@ -1,174 +0,0 @@
-// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.vespa.config.server.deploy;
-
-import com.google.common.collect.ImmutableSet;
-import com.yahoo.component.Version;
-import com.yahoo.config.application.api.ApplicationMetaData;
-import com.yahoo.config.application.api.ApplicationPackage;
-import com.yahoo.config.application.api.FileRegistry;
-import com.yahoo.config.model.application.provider.BaseDeployLogger;
-import com.yahoo.config.model.application.provider.DeployData;
-import com.yahoo.config.model.application.provider.FilesApplicationPackage;
-import com.yahoo.config.model.application.provider.MockFileRegistry;
-import com.yahoo.config.provision.AllocatedHosts;
-import com.yahoo.config.provision.ApplicationId;
-import com.yahoo.config.provision.HostSpec;
-import com.yahoo.path.Path;
-import com.yahoo.text.Utf8;
-import com.yahoo.vespa.config.server.zookeeper.ZKApplicationPackage;
-import com.yahoo.vespa.curator.Curator;
-import com.yahoo.vespa.curator.mock.MockCurator;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.TemporaryFolder;
-
-import java.io.File;
-import java.io.IOException;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-
-import static com.yahoo.config.provision.serialization.AllocatedHostsSerializer.fromJson;
-import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.DEFCONFIGS_ZK_SUBPATH;
-import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.META_ZK_PATH;
-import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.USERAPP_ZK_SUBPATH;
-import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.USER_DEFCONFIGS_ZK_SUBPATH;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-
-/**
- * Unit tests for ZooKeeperClient.
- *
- * @author hmusum
- */
-public class ZooKeeperClientTest {
-
-    @Rule
-    public TemporaryFolder temporaryFolder = new TemporaryFolder();
-
-    private Curator zk;
-    private final Path appPath = Path.fromString("/1");
-
-    @Before
-    public void setupZK() throws IOException {
-        zk = new MockCurator();
-        ZooKeeperClient zkc = new ZooKeeperClient(zk, new BaseDeployLogger(), appPath);
-        ApplicationPackage app = FilesApplicationPackage.fromFileWithDeployData(new File("src/test/apps/zkfeed"),
-                                                                                new DeployData("/bar/baz",
-                                                                                               ApplicationId.from("default", "appName", "default"),
-                                                                                               1345L,
-                                                                                               true,
-                                                                                               3L,
-                                                                                               2L));
-        Map<Version, FileRegistry> fileRegistries = createFileRegistries();
-        app.writeMetaData();
-        zkc.initialize();
-        zkc.writeApplicationPackage(app);
-        zkc.write(fileRegistries);
-    }
-
-    private Map<Version, FileRegistry> createFileRegistries() {
-        FileRegistry a = new MockFileRegistry();
-        a.addFile("fileA");
-        FileRegistry b = new MockFileRegistry();
-        b.addFile("fileB");
-        Map<Version, FileRegistry> registryMap = new HashMap<>();
-        registryMap.put(new Version(1, 2, 3), a);
-        registryMap.put(new Version(3, 2, 1), b);
-        return registryMap;
-    }
-
-    @Test
-    public void testInitZooKeeper() {
-        Curator zk = new MockCurator();
-        BaseDeployLogger logger = new BaseDeployLogger();
-        long generation = 1L;
-        ZooKeeperClient zooKeeperClient = new ZooKeeperClient(zk, logger, Path.fromString("/1"));
-        zooKeeperClient.initialize();
-        Path appPath = Path.fromString("/");
-        assertEquals(1, zk.getChildren(appPath).size());
-        Path currentAppPath = appPath.append(String.valueOf(generation));
-        assertTrue(zk.exists(currentAppPath));
-        assertTrue(zk.exists(currentAppPath.append(DEFCONFIGS_ZK_SUBPATH.replaceFirst("/", ""))));
-        assertEquals(4, zk.getChildren(currentAppPath).size());
-    }
-
-    @Test
-    public void testFeedDefFilesToZooKeeper() {
-        Path defsPath = appPath.append(DEFCONFIGS_ZK_SUBPATH);
-        assertTrue(zk.exists(appPath.append(DEFCONFIGS_ZK_SUBPATH.replaceFirst("/", ""))));
-        List<String> children = zk.getChildren(defsPath);
-        assertEquals(defsPath + " children", 1, children.size());
-        Collections.sort(children);
-        assertEquals("a.b.test2", children.get(0));
-
-        assertTrue(zk.exists(appPath.append(USER_DEFCONFIGS_ZK_SUBPATH.replaceFirst("/", ""))));
-        Path userDefsPath = appPath.append(USER_DEFCONFIGS_ZK_SUBPATH);
-        children = zk.getChildren(userDefsPath);
-        assertEquals(1, children.size());
-        Collections.sort(children);
-        assertEquals("a.b.test2", children.get(0));
-    }
-
-    @Test
-    public void testFeedAppMetaDataToZooKeeper() {
-        assertTrue(zk.exists(appPath.append(META_ZK_PATH)));
-        ApplicationMetaData metaData = ApplicationMetaData.fromJsonString(
-                Utf8.toString(zk.getData(appPath.append(META_ZK_PATH)).get()));
-        assertTrue(metaData.getChecksum().length() > 0);
-        assertTrue(metaData.isInternalRedeploy());
-        assertEquals("/bar/baz", metaData.getDeployPath());
-        assertEquals(1345, metaData.getDeployTimestamp().longValue());
-        assertEquals(3, metaData.getGeneration().longValue());
-        assertEquals(2, metaData.getPreviousActiveGeneration());
-    }
-
-    @Test
-    public void testVersionedFileRegistry() {
-        Path fileRegPath = appPath.append(ZKApplicationPackage.fileRegistryNode);
-        assertTrue(zk.exists(fileRegPath));
-        assertTrue(zk.exists(fileRegPath.append("/1.2.3")));
-        assertTrue(zk.exists(fileRegPath.append("/3.2.1")));
-        // assertNull("Data at " + fileRegPath, zk.getData(fileRegPath)); Not null any more .. hm
-    }
-
-    @Test
-    public void include_dirs_are_written_to_ZK() {
-        assertTrue(zk.exists(appPath.append(USERAPP_ZK_SUBPATH).append("dir1").append("default.xml")));
-        assertTrue(zk.exists(appPath.append(USERAPP_ZK_SUBPATH).append("nested").append("dir2").append("chain2.xml")));
-        assertTrue(zk.exists(appPath.append(USERAPP_ZK_SUBPATH).append("nested").append("dir2").append("chain3.xml")));
-    }
-
-    @Test
-    public void search_chain_dir_written_to_ZK() {
-        assertTrue(zk.exists(appPath().append("search").append("chains").append("dir1").append("default.xml")));
-        assertTrue(zk.exists(appPath().append("search").append("chains").append("dir2").append("chain2.xml")));
-        assertTrue(zk.exists(appPath().append("search").append("chains").append("dir2").append("chain3.xml")));
-    }
-
-    private Path appPath() {
-        return appPath.append(USERAPP_ZK_SUBPATH);
-    }
-
-    @Test
-    public void testWritingHostNamesToZooKeeper() throws IOException {
-        Curator zk = new MockCurator();
-        BaseDeployLogger logger = new BaseDeployLogger();
-        Path app = Path.fromString("/1");
-        ZooKeeperClient zooKeeperClient = new ZooKeeperClient(zk, logger, app);
-        zooKeeperClient.initialize();
-        HostSpec host1 = new HostSpec("host1.yahoo.com", Optional.empty());
-        HostSpec host2 = new HostSpec("host2.yahoo.com", Optional.empty());
-        ImmutableSet<HostSpec> hosts = ImmutableSet.of(host1, host2);
-        zooKeeperClient.write(AllocatedHosts.withHosts(hosts));
-        Path hostsPath = app.append(ZKApplicationPackage.allocatedHostsNode);
-        assertTrue(zk.exists(hostsPath));
-        
-        AllocatedHosts deserialized = fromJson(zk.getData(hostsPath).get());
-        assertEquals(hosts, deserialized.getHosts());
-    }
-
-}
diff --git a/configserver/src/test/java/com/yahoo/vespa/config/server/deploy/ZooKeeperDeployerTest.java b/configserver/src/test/java/com/yahoo/vespa/config/server/deploy/ZooKeeperDeployerTest.java
index 1bc980c9099..17344e94c51 100644
--- a/configserver/src/test/java/com/yahoo/vespa/config/server/deploy/ZooKeeperDeployerTest.java
+++ b/configserver/src/test/java/com/yahoo/vespa/config/server/deploy/ZooKeeperDeployerTest.java
@@ -1,16 +1,26 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config.server.deploy;
 
+import com.google.common.collect.ImmutableSet;
 import com.yahoo.component.Version;
+import com.yahoo.config.application.api.ApplicationMetaData;
 import com.yahoo.config.application.api.ApplicationPackage;
 import com.yahoo.config.application.api.DeployLogger;
+import com.yahoo.config.application.api.FileRegistry;
+import com.yahoo.config.model.application.provider.BaseDeployLogger;
+import com.yahoo.config.model.application.provider.DeployData;
 import com.yahoo.config.model.application.provider.FilesApplicationPackage;
 import com.yahoo.config.model.application.provider.MockFileRegistry;
 import com.yahoo.config.provision.AllocatedHosts;
+import com.yahoo.config.provision.ApplicationId;
+import com.yahoo.config.provision.HostSpec;
 import com.yahoo.io.IOUtils;
 import com.yahoo.path.Path;
+import com.yahoo.text.Utf8;
+import com.yahoo.vespa.config.server.zookeeper.ZKApplicationPackage;
 import com.yahoo.vespa.curator.Curator;
 import com.yahoo.vespa.curator.mock.MockCurator;
+import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -18,8 +28,20 @@ import org.junit.rules.TemporaryFolder;
 import java.io.File;
 import java.io.IOException;
 import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
 import java.util.logging.Level;
 
+import static com.yahoo.config.provision.serialization.AllocatedHostsSerializer.fromJson;
+import static com.yahoo.vespa.config.server.session.SessionZooKeeperClient.getSessionPath;
+import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.DEFCONFIGS_ZK_SUBPATH;
+import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.META_ZK_PATH;
+import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.USERAPP_ZK_SUBPATH;
+import static com.yahoo.vespa.config.server.zookeeper.ZKApplication.USER_DEFCONFIGS_ZK_SUBPATH;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
@@ -28,10 +50,31 @@ import static org.junit.Assert.fail;
  */
 public class ZooKeeperDeployerTest {
 
+    private Curator zk;
+    private final Path appPath = Path.fromString("/1");
+
     @Rule
     public TemporaryFolder folder = new TemporaryFolder();
     private static final String defFile = "test2.def";
 
+    @Before
+    public void setupZK() throws IOException {
+        zk = new MockCurator();
+        ZooKeeperDeployer.Client zkc = new ZooKeeperDeployer.Client(zk, new BaseDeployLogger(), appPath);
+        ApplicationPackage app = FilesApplicationPackage.fromFileWithDeployData(new File("src/test/apps/zkfeed"),
+                                                                                new DeployData("/bar/baz",
+                                                                                               ApplicationId.from("default", "appName", "default"),
+                                                                                               1345L,
+                                                                                               true,
+                                                                                               3L,
+                                                                                               2L));
+        Map<Version, FileRegistry> fileRegistries = createFileRegistries();
+        app.writeMetaData();
+        zkc.initialize();
+        zkc.writeApplicationPackage(app);
+        zkc.write(fileRegistries);
+    }
+
     @Test
     public void require_that_deployer_is_initialized() throws IOException {
         Curator curator = new MockCurator();
@@ -43,17 +86,117 @@ public class ZooKeeperDeployerTest {
             e.printStackTrace();
             fail();
         }
-        deploy(FilesApplicationPackage.fromFile(new File("src/test/apps/content")), curator, Path.fromString("/1"));
-        deploy(FilesApplicationPackage.fromFile(new File("src/test/apps/content")), curator, Path.fromString("/2"));
+        deploy(FilesApplicationPackage.fromFile(new File("src/test/apps/content")), curator, 1);
+        deploy(FilesApplicationPackage.fromFile(new File("src/test/apps/content")), curator, 2);
+    }
+
+    private Map<Version, FileRegistry> createFileRegistries() {
+        FileRegistry a = new MockFileRegistry();
+        a.addFile("fileA");
+        FileRegistry b = new MockFileRegistry();
+        b.addFile("fileB");
+        Map<Version, FileRegistry> registryMap = new HashMap<>();
+        registryMap.put(new Version(1, 2, 3), a);
+        registryMap.put(new Version(3, 2, 1), b);
+        return registryMap;
+    }
+
+    @Test
+    public void testInitZooKeeper() {
+        Curator zk = new MockCurator();
+        BaseDeployLogger logger = new BaseDeployLogger();
+        long generation = 1L;
+        ZooKeeperDeployer.Client client = new ZooKeeperDeployer.Client(zk, logger, Path.fromString("/1"));
+        client.initialize();
+        Path appPath = Path.fromString("/");
+        assertEquals(1, zk.getChildren(appPath).size());
+        Path currentAppPath = appPath.append(String.valueOf(generation));
+        assertTrue(zk.exists(currentAppPath));
+        assertTrue(zk.exists(currentAppPath.append(DEFCONFIGS_ZK_SUBPATH.replaceFirst("/", ""))));
+        assertEquals(4, zk.getChildren(currentAppPath).size());
+    }
+
+    @Test
+    public void testFeedDefFilesToZooKeeper() {
+        Path defsPath = appPath.append(DEFCONFIGS_ZK_SUBPATH);
+        assertTrue(zk.exists(appPath.append(DEFCONFIGS_ZK_SUBPATH.replaceFirst("/", ""))));
+        List<String> children = zk.getChildren(defsPath);
+        assertEquals(defsPath + " children", 1, children.size());
+        Collections.sort(children);
+        assertEquals("a.b.test2", children.get(0));
+
+        assertTrue(zk.exists(appPath.append(USER_DEFCONFIGS_ZK_SUBPATH.replaceFirst("/", ""))));
+        Path userDefsPath = appPath.append(USER_DEFCONFIGS_ZK_SUBPATH);
+        children = zk.getChildren(userDefsPath);
+        assertEquals(1, children.size());
+        Collections.sort(children);
+        assertEquals("a.b.test2", children.get(0));
+    }
+
+    @Test
+    public void testFeedAppMetaDataToZooKeeper() {
+        assertTrue(zk.exists(appPath.append(META_ZK_PATH)));
+        ApplicationMetaData metaData = ApplicationMetaData.fromJsonString(
+                Utf8.toString(zk.getData(appPath.append(META_ZK_PATH)).get()));
+        assertTrue(metaData.getChecksum().length() > 0);
+        assertTrue(metaData.isInternalRedeploy());
+        assertEquals("/bar/baz", metaData.getDeployPath());
+        assertEquals(1345, metaData.getDeployTimestamp().longValue());
+        assertEquals(3, metaData.getGeneration().longValue());
+        assertEquals(2, metaData.getPreviousActiveGeneration());
+    }
+
+    @Test
+    public void testVersionedFileRegistry() {
+        Path fileRegPath = appPath.append(ZKApplicationPackage.fileRegistryNode);
+        assertTrue(zk.exists(fileRegPath));
+        assertTrue(zk.exists(fileRegPath.append("/1.2.3")));
+        assertTrue(zk.exists(fileRegPath.append("/3.2.1")));
+        // assertNull("Data at " + fileRegPath, zk.getData(fileRegPath)); Not null any more .. hm
+    }
+
+    @Test
+    public void include_dirs_are_written_to_ZK() {
+        assertTrue(zk.exists(appPath.append(USERAPP_ZK_SUBPATH).append("dir1").append("default.xml")));
+        assertTrue(zk.exists(appPath.append(USERAPP_ZK_SUBPATH).append("nested").append("dir2").append("chain2.xml")));
+        assertTrue(zk.exists(appPath.append(USERAPP_ZK_SUBPATH).append("nested").append("dir2").append("chain3.xml")));
+    }
+
+    @Test
+    public void search_chain_dir_written_to_ZK() {
+        assertTrue(zk.exists(appPath().append("search").append("chains").append("dir1").append("default.xml")));
+        assertTrue(zk.exists(appPath().append("search").append("chains").append("dir2").append("chain2.xml")));
+        assertTrue(zk.exists(appPath().append("search").append("chains").append("dir2").append("chain3.xml")));
+    }
+
+    private Path appPath() {
+        return appPath.append(USERAPP_ZK_SUBPATH);
+    }
+
+    @Test
+    public void testWritingHostNamesToZooKeeper() throws IOException {
+        Curator zk = new MockCurator();
+        BaseDeployLogger logger = new BaseDeployLogger();
+        Path app = Path.fromString("/1");
+        ZooKeeperDeployer.Client client = new ZooKeeperDeployer.Client(zk, logger, app);
+        client.initialize();
+        HostSpec host1 = new HostSpec("host1.yahoo.com", Optional.empty());
+        HostSpec host2 = new HostSpec("host2.yahoo.com", Optional.empty());
+        ImmutableSet<HostSpec> hosts = ImmutableSet.of(host1, host2);
+        client.write(AllocatedHosts.withHosts(hosts));
+        Path hostsPath = app.append(ZKApplicationPackage.allocatedHostsNode);
+        assertTrue(zk.exists(hostsPath));
+
+        AllocatedHosts deserialized = fromJson(zk.getData(hostsPath).get());
+        assertEquals(hosts, deserialized.getHosts());
     }
 
-    public void deploy(ApplicationPackage applicationPackage, Curator curator, Path appPath) throws IOException {
-        MockDeployLogger logger = new MockDeployLogger();
-        ZooKeeperClient client = new ZooKeeperClient(curator, logger, appPath);
-        ZooKeeperDeployer deployer = new ZooKeeperDeployer(client);
+    public void deploy(ApplicationPackage applicationPackage, Curator curator, long sessionId) throws IOException {
+        ZooKeeperDeployer deployer = new ZooKeeperDeployer(curator, new MockDeployLogger(), applicationPackage.getApplicationId(), sessionId);
+        deployer.deploy(applicationPackage, Map.of(new Version(1, 0, 0), new MockFileRegistry()), AllocatedHosts.withHosts(Set.of()));
 
-        deployer.deploy(applicationPackage, Collections.singletonMap(new Version(1, 0, 0), new MockFileRegistry()), AllocatedHosts.withHosts(Collections.emptySet()));
-        assertTrue(curator.exists(appPath));
+        Path sessionPath = getSessionPath(applicationPackage.getApplicationId().tenant(), sessionId);
+        assertTrue(curator.exists(sessionPath));
     }
 
     private static class MockDeployLogger implements DeployLogger {