add zookeeper 3.6.0

Change-Id: I8065817b34e103a7149293f39cd1634260849065

zookeeper/Dockerfile

-FROM registry-vpc.cn-hangzhou.aliyuncs.com/schbrain/jdk:8u172-1.0
-
-ENV ZOO_CONF_DIR=/conf \
-    ZOO_DATA_DIR=/data \
-    ZOO_DATA_LOG_DIR=/datalog \
-    ZOO_LOG_DIR=/logs \
-    ZOO_TICK_TIME=2000 \
-    ZOO_INIT_LIMIT=5 \
-    ZOO_SYNC_LIMIT=2 \
-    ZOO_AUTOPURGE_PURGEINTERVAL=0 \
-    ZOO_AUTOPURGE_SNAPRETAINCOUNT=3 \
-    ZOO_MAX_CLIENT_CNXNS=60 \
-    ZOO_STANDALONE_ENABLED=true \
-    ZOO_ADMINSERVER_ENABLED=true
-
-# Add a user with an explicit UID/GID and create necessary directories
-RUN set -eux; \
-    groupadd -r zookeeper --gid=1000; \
-    useradd -r -g zookeeper --uid=1000 zookeeper; \
-    mkdir -p "$ZOO_DATA_LOG_DIR" "$ZOO_DATA_DIR" "$ZOO_CONF_DIR" "$ZOO_LOG_DIR"; \
-    chown zookeeper:zookeeper "$ZOO_DATA_LOG_DIR" "$ZOO_DATA_DIR" "$ZOO_CONF_DIR" "$ZOO_LOG_DIR"
-
-# Install required packges
-RUN set -eux; \
-    apt-get update; \
-    DEBIAN_FRONTEND=noninteractive \
-    apt-get install -y --no-install-recommends \
-        ca-certificates \
-        dirmngr \
-        gosu \
-        gnupg \
-        netcat \
-        wget; \
-    rm -rf /var/lib/apt/lists/*; \
-# Verify that gosu binary works
-    gosu nobody true
-
-ARG GPG_KEY=BBE7232D7991050B54C8EA0ADC08637CA615D22C
-ARG SHORT_DISTRO_NAME=zookeeper-3.6.0
-ARG DISTRO_NAME=apache-zookeeper-3.6.0-bin
-
-# Download Apache Zookeeper, verify its PGP signature, untar and clean up
-RUN set -eux; \
-    ddist() { \
-        local f="$1"; shift; \
-        local distFile="$1"; shift; \
-        local success=; \
-        local distUrl=; \
-        for distUrl in \
-            'https://www.apache.org/dyn/closer.cgi?action=download&filename=' \
-            https://www-us.apache.org/dist/ \
-            https://www.apache.org/dist/ \
-            https://archive.apache.org/dist/ \
-        ; do \
-            if wget -q -O "$f" "$distUrl$distFile" && [ -s "$f" ]; then \
-                success=1; \
-                break; \
-            fi; \
-        done; \
-        [ -n "$success" ]; \
-    }; \
-    ddist "$DISTRO_NAME.tar.gz" "zookeeper/$SHORT_DISTRO_NAME/$DISTRO_NAME.tar.gz"; \
-    ddist "$DISTRO_NAME.tar.gz.asc" "zookeeper/$SHORT_DISTRO_NAME/$DISTRO_NAME.tar.gz.asc"; \
-    export GNUPGHOME="$(mktemp -d)"; \
-    #gpg --keyserver ha.pool.sks-keyservers.net --recv-key "$GPG_KEY" || \
-    #gpg --keyserver pgp.mit.edu --recv-keys "$GPG_KEY" || \
-    #gpg --keyserver keyserver.pgp.com --recv-keys "$GPG_KEY"; \
-    #gpg --batch --verify "$DISTRO_NAME.tar.gz.asc" "$DISTRO_NAME.tar.gz"; \
-    tar -zxf "$DISTRO_NAME.tar.gz"; \
-    mv "$DISTRO_NAME/conf/"* "$ZOO_CONF_DIR"; \
-    rm -rf "$GNUPGHOME" "$DISTRO_NAME.tar.gz" "$DISTRO_NAME.tar.gz.asc"; \
-    chown -R zookeeper:zookeeper "/$DISTRO_NAME"
-
-WORKDIR $DISTRO_NAME
-VOLUME ["$ZOO_DATA_DIR", "$ZOO_DATA_LOG_DIR", "$ZOO_LOG_DIR"]
-
-EXPOSE 2181 2888 3888 8080
-
-ENV PATH=$PATH:/$DISTRO_NAME/bin \
-    ZOOCFGDIR=$ZOO_CONF_DIR
-
-COPY docker-entrypoint.sh /
-ENTRYPOINT ["/docker-entrypoint.sh"]
-CMD ["zkServer.sh", "start-foreground"]
+FROM ubuntu:16.04
+
+ENV ZK_USER=zookeeper \
+    ZK_DATA_DIR=/var/lib/zookeeper/data \
+    ZK_DATA_LOG_DIR=/var/lib/zookeeper/log \
+    ZK_LOG_DIR=/var/log/zookeeper \
+    JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
+
+ARG GPG_KEY=C823E3E5B12AF29C67F81976F5CECB3CB5E9BD2D
+ARG ZK_DIST=apache-zookeeper-3.6.0-bin
+
+COPY sources.list /etc/apt/sources.list
+
+ADD $ZK_DIST.tar.gz /opt/
+
+RUN set -x \
+    && apt-get update \
+    #&& apt-get install -y openjdk-8-jre-headless wget netcat-openbsd \
+    && apt-get install -y openjdk-8-jre-headless netcat-openbsd \
+    #&& wget -q "http://www.apache.org/dist/zookeeper/$ZK_DIST/$ZK_DIST.tar.gz" \
+    #&& wget -q "http://www.apache.org/dist/zookeeper/$ZK_DIST/$ZK_DIST.tar.gz.asc" \
+    #&& export GNUPGHOME="$(mktemp -d)" \
+    #&& gpg --keyserver ha.pool.sks-keyservers.net --recv-key "$GPG_KEY" \
+    #&& gpg --batch --verify "$ZK_DIST.tar.gz.asc" "$ZK_DIST.tar.gz" \
+    #&& tar -xzf "$ZK_DIST.tar.gz" -C /opt \
+    #&& rm -r "$GNUPGHOME" "$ZK_DIST.tar.gz" "$ZK_DIST.tar.gz.asc" \
+    && ln -s /opt/$ZK_DIST /opt/zookeeper \
+    && rm -rf /opt/zookeeper/CHANGES.txt \
+    /opt/zookeeper/README.txt \
+    /opt/zookeeper/NOTICE.txt \
+    /opt/zookeeper/CHANGES.txt \
+    /opt/zookeeper/README_packaging.txt \
+    /opt/zookeeper/build.xml \
+    /opt/zookeeper/config \
+    /opt/zookeeper/contrib \
+    /opt/zookeeper/dist-maven \
+    /opt/zookeeper/docs \
+    /opt/zookeeper/ivy.xml \
+    /opt/zookeeper/ivysettings.xml \
+    /opt/zookeeper/recipes \
+    /opt/zookeeper/src \
+    /opt/zookeeper/$ZK_DIST.jar.asc \
+    /opt/zookeeper/$ZK_DIST.jar.md5 \
+    /opt/zookeeper/$ZK_DIST.jar.sha1 \
+    #&& apt-get autoremove -y wget \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy configuration generator script to bin
+COPY zkGenConfig.sh zkOk.sh zkMetrics.sh /opt/zookeeper/bin/
+
+# Create a user for the zookeeper process and configure file system ownership
+# for necessary directories and symlink the distribution as a user executable
+RUN set -x \
+    && useradd $ZK_USER \
+    && [ `id -u $ZK_USER` -eq 1000 ] \
+    && [ `id -g $ZK_USER` -eq 1000 ] \
+    && mkdir -p $ZK_DATA_DIR $ZK_DATA_LOG_DIR $ZK_LOG_DIR /usr/share/zookeeper /tmp/zookeeper /usr/etc/ \
+    && chown -R "$ZK_USER:$ZK_USER" /opt/$ZK_DIST $ZK_DATA_DIR $ZK_LOG_DIR $ZK_DATA_LOG_DIR /tmp/zookeeper \
+    && ln -s /opt/zookeeper/conf/ /usr/etc/zookeeper \
+    && ln -s /opt/zookeeper/bin/* /usr/bin \
+    && ln -s /opt/zookeeper/$ZK_DIST.jar /usr/share/zookeeper/ \
+    && ln -s /opt/zookeeper/lib/* /usr/share/zookeeper

zookeeper/LICENSE

+Copyright 2014 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
\ No newline at end of file

zookeeper/Makefile

+VERSION=v3
+PROJECT_ID=google_samples
+PROJECT=gcr.io/${PROJECT_ID}
+
+all: build
+
+build:
+	docker build --pull -t ${PROJECT}/k8szk:${VERSION} .
+
+push: build
+	gcloud docker -- push ${PROJECT}/k8szk:${VERSION}
+
+.PHONY: all build push

zookeeper/OWNERS

+approvers:
+- bprashanth
+- enisoc
+- erictune
+- foxish
+- janetkuo
+- kow3ns

zookeeper/README.md

+# Kubernetes ZooKeeper K8SZK
+This project contains a Docker image meant to facilitate the deployment of 
+[Apache ZooKeeper](https://zookeeper.apache.org/) on [Kubernetes](http://kubernetes.io/) using 
+[StatefulSets](https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/). 
+## Limitations
+1. Scaling is not currently supported. An ensemble's membership can not be updated in a safe way 
+in ZooKeeper 3.4.10 (The current stable release).
+2. Observers are currently not supported. Contributions are welcome.
+3. Persistent Volumes must be used. emptyDirs will likely result in a loss of data.
+
+## Docker Image
+The docker image contained in this repository is comprised of a base Ubuntu 16.04 image using the latest
+release of the OpenJDK JRE based on the 1.8 JVM (JDK 8u111) and the latest stable release of 
+ZooKeeper, 3.4.10. Ubuntu is a much larger image than BusyBox or Alpine, but these images contain
+mucl or ulibc. This requires a custom version of OpenJDK to be built against a libc runtime other 
+than glibc. No vendor of the ZooKeeper software supplies or verifies the software against such a 
+JVM, and, while Alpine or BusyBox would provide smaller images, we have prioritized a well known 
+environment.
+
+The image is built such that the ZooKeeper process is designated to run as a non-root user. By default, 
+this user is zookeeper. The ZooKeeper package is installed into the /opt/zookeeper directory, all 
+configuration is sym linked into the /usr/etc/zookeeper/, and all executables are sym linked into 
+/usr/bin. The ZooKeeper data directories are contained in /var/lib/zookeeper. This is identical to 
+the RPM distribution that users should be familiar with.
+
+## Configuration
+
+### Headless Service
+The ZooKeeper Stateful Set requires a Headless Service to control the network domain for the 
+ZooKeeper processes. An example configuration is provided below.
+
+```yaml
+apiVersion: v1
+kind: Service
+metadata:
+  name: zk-svc
+  labels:
+    app: zk-svc
+spec:
+  ports:
+  - port: 2888
+    name: server
+  - port: 3888
+    name: leader-election
+  clusterIP: None
+  selector:
+    app: zk-svc
+```
+Note that the Service contains two ports. The server port is used for followers to tail the leaders
+even log, and the leader-election port is used by the ensemble to perform leader election.
+### Stateful Set
+The Stateful Set configuration must match the Headless Service, and it must provide the number of 
+replicas. In the example below we request a ZooKeeper ensemble of size 3. 
+**As weighted quorums are not supported, it is imperative that an odd number of replicas be chosen.
+Moreover, the number of replicas should be either 1, 3, 5, or 7. Ensembles may be scaled to larger 
+membership for read fan out, but, as this will adversely impact write performance, careful thought
+should be given to selecting a larger value.**
+```yaml
+apiVersion: apps/v1beta1
+kind: StatefulSet
+metadata:
+  name: zk
+spec:
+  serviceName: zk-svc
+  replicas: 3
+```
+### Container Configuration
+The zkGenConfig.sh script will generate the ZooKeeper configuration (zoo.cfg), Log4J configuration
+(log4j.properties), and JVM configuration (jvm.env). These will be written to the 
+/opt/zookeeper/conf directory with correct read permissions for the zookeeper user. These files are 
+generated from environment variables that are injected into the container as in the example, minimal 
+configuration below.
+```yaml
+containers:
+      - name: k8szk
+        imagePullPolicy: Always
+        image: gcr.io/google_samples/k8szk:v3
+        ports:
+        - containerPort: 2181
+          name: client
+        - containerPort: 2888
+          name: server
+        - containerPort: 3888
+          name: leader-election
+        env:
+        - name : ZK_ENSEMBLE
+          value: "zk-0;zk-1;zk-2"
+        - name: ZK_CLIENT_PORT
+          value: "2181"
+        - name: ZK_SERVER_PORT
+          value: "2888"
+        - name: ZK_ELECTION_PORT
+          value: "3888"
+```
+#### Membership Configuration
+|Variable|Type|Default|Description|
+|:------:|:---:|:-----:|:---------|
+|ZK_ENSEMBLE|string|N/A|A colon separated list of servers in the ensemble.|
+This is a mandatory configuration variable that is used to configure the membership of the 
+ZooKeeper ensemble. It is also used to prevent data loss during accidental scale operations. The 
+set can be computed as follows. For all integers in the range [0,replicas), prepend the name of 
+service followed by a dash to the integer. So for the Stateful Set above, the name is zk and we have
+3 replicas. for the set {0,1,2} we prepend zk- giving us zk-0;zk-1;zk-2.
+
+#### Network Configuration
+|Variable|Type|Default|Description|
+|:------:|:---:|:-----:|:--------|
+|ZK_CLIENT_PORT|integer|2181|The port on which the server will accept client requests.|
+|ZK_SERVER_PORT|integer|2888|The port on which the leader will send events to followers.|
+|ZK_ELECTION_PORT|integer|3888|The port on which the ensemble performs leader election.|
+|ZK_MAX_CLIENT_CNXNS|integer|60|The maximum number of concurrent client connections that a server in the ensemble will accept.|
+
+The ZK_CLIENT_PORT, ZK_ELECTION_PORT, and ZK_SERVERS_PORT must be set to the containerPorts 
+specified in the container configuration, and the ZK_SERVER_PORT and ZK_ELECTION_PORT 
+must match the Headless Service configuration. However, if the default values of 
+the environment variables are used for both the containerPorts and the Headless Service, the 
+environment variables may be omitted from the configuration.
+
+#### ZooKeeper Time Configuration
+|Variable|Type|Default|Description|
+|:------:|:---:|:-----:|:--------|
+|ZK_TICK_TIME|integer|2000|The number of wall clock ms that corresponds to a Tick for the ensembles internal time.|
+|ZK_INIT_LIMIT|integer|5|The number of Ticks that an ensemble member is allowed to perform leader election.|
+|ZK_SYNC_LIMIT|integer|10|The number of Tick by which a follower may lag behind the ensembles leader.|
+
+#### ZooKeeper Session Configuration
+|Variable|Type|Default|Description|
+|:------:|:---:|:-----:|:--------|
+|ZK_MIN_SESSION_TIMEOUT|integer|2 * ZK_TICK_TIME|The minimum session timeout that the ensemble will allow a client to request.|
+|ZK_MAX_SESSION_TIMEOUT|integer|20 * ZK_TICK_TIME|The maximum session timeout that the ensemble will allow a client to request.|
+
+#### Data Retention Configuration
+**ZooKeeper does not, by default, purge old transactions logs or snapshots. This can cause 
+the disk to become full.** If you have backup procedures and retention policies that rely on 
+external systems, the snapshots can be retrieved manually from the /var/lib/zookeeper/data directory,
+and the logs can be retrieved manually from the /var/lib/zookeeper/log directory.
+These will be stored on the persistent volume. The zkCleanup.sh script can be used to manually purge
+outdated logs and snapshots.
+
+If you do not have an existing retention policy and backup procedure, and if you are comfortable with 
+an automatic procedure, you can use the environment variables below to enable and configure 
+automatic data purge policies.
+
+|Variable|Type|Default|Description|
+|:------:|:---:|:-----:|:---------|
+|ZK_SNAP_RETAIN_COUNT|integer|3|The number of snapshots that the ZooKeeper process will retain if ZK_PURGE_INTERVAL is set to a value greater than 0.|
+|ZK_PURGE_INTERVAL|integer|0|The delay, in hours, between ZooKeeper log and snapshot cleanups.|
+
+#### JVM Configuration
+Currently the only supported JVM configuration is the JVM heap size. Be sure that the heap size you
+request does not cause the process to swap out.
+
+|Variable|Type|Default|Description|
+|:------:|:---:|:-----:|:--------|
+|ZK_HEAP_SIZE|integer|2|The JVM heap size in Gibibytes.|
+
+#### Log Level Configuration
+|Variable|Type|Default|Description|
+|:------:|:---:|:-----:|:--------|
+|ZK_LOG_LEVEL|enum(TRACE,DEBUG,INFO,WARN,ERROR,FATAL)|INFO|The Log Level that for the ZooKeeper processes logger.|
+
+#### Liveness and Readiness
+The zkOk.sh script can be used to check the liveness and readiness of ZooKeeper process. The example 
+below demonstrates how to configure liveness and readiness probes for the Pods in the Stateful Set.
+```yaml
+  readinessProbe:
+    exec:
+      command:
+      - sh
+      - -c
+      - "zkOk.sh"
+    initialDelaySeconds: 15 
+    timeoutSeconds: 5
+  livenessProbe:
+    exec:
+      command:
+      - sh
+      - -c
+      - "zkOk.sh"
+    initialDelaySeconds: 15
+    timeoutSeconds: 5
+```
+#### Volume Mounts
+volumeMounts for the container should be defined as below.
+```yaml
+  volumeMounts:
+  - name: datadir
+    mountPath: /var/lib/zookeeper
+```
+### Storage Configuration
+Currently, the use of Persistent Volumes to provide durable, network attached storage is mandatory.
+**If you use the provided image with emptyDirs, you will likely suffer a data loss.** The example 
+below demonstrates how to request a dynamically provisioned persistent volume of 20 GiB.
+```yaml
+  volumeClaimTemplates:
+  - metadata:
+      name: datadir
+      annotations:
+        volume.alpha.kubernetes.io/storage-class: anything
+    spec:
+      accessModes: [ "ReadWriteOnce" ]
+      resources:
+        requests:
+          storage: 20Gi
+```
+
+### Logging 
+The Log Level configuration may be modified via the ZK_LOG_LEVEL environment variable as described 
+above. However, the location of the log output is not modifiable. The ZooKeeper process must be 
+run in the foreground, and the log information will be shipped to the stdout. This is considered 
+to be a best practice for containerized applications, and it allows users to make use of the 
+log rotation and retention infrastructure that already exists for K8s.
+
+### Metrics 
+The zkMetrics script can be used to retrieve metrics from the ZooKeeper process and print them to 
+stdout. A recurring Kubernetes job can be used to collect these metrics and provide them to a 
+collector.
+```bash
+bash$ kubectl exec zk-0 zkMetrics.sh
+zk_version	3.4.9-1757313, built on 08/23/2016 06:50 GMT
+zk_avg_latency	0
+zk_max_latency	0
+zk_min_latency	0
+zk_packets_received	21
+zk_packets_sent	20
+zk_num_alive_connections	1
+zk_outstanding_requests	0
+zk_server_state	follower
+zk_znode_count	4
+zk_watch_count	0
+zk_ephemerals_count	0
+zk_approximate_data_size	27
+zk_open_file_descriptor_count	39
+zk_max_file_descriptor_count	1048576
+
+```

zookeeper/docker-entrypoint.sh

-#!/bin/bash
-
-set -e
-
-# Allow the container to be started with `--user`
-if [[ "$1" = 'zkServer.sh' && "$(id -u)" = '0' ]]; then
-    chown -R zookeeper "$ZOO_DATA_DIR" "$ZOO_DATA_LOG_DIR" "$ZOO_LOG_DIR" "$ZOO_CONF_DIR"
-    exec gosu zookeeper "$0" "$@"
-fi
-
-# Generate the config only if it doesn't exist
-if [[ ! -f "$ZOO_CONF_DIR/zoo.cfg" ]]; then
-    CONFIG="$ZOO_CONF_DIR/zoo.cfg"
-    {
-        echo "dataDir=$ZOO_DATA_DIR" 
-        echo "dataLogDir=$ZOO_DATA_LOG_DIR"
-
-        echo "tickTime=$ZOO_TICK_TIME"
-        echo "initLimit=$ZOO_INIT_LIMIT"
-        echo "syncLimit=$ZOO_SYNC_LIMIT"
-
-        echo "autopurge.snapRetainCount=$ZOO_AUTOPURGE_SNAPRETAINCOUNT"
-        echo "autopurge.purgeInterval=$ZOO_AUTOPURGE_PURGEINTERVAL"
-        echo "maxClientCnxns=$ZOO_MAX_CLIENT_CNXNS"
-        echo "standaloneEnabled=$ZOO_STANDALONE_ENABLED"
-        echo "admin.enableServer=$ZOO_ADMINSERVER_ENABLED"
-    } >> "$CONFIG"
-    if [[ -z $ZOO_SERVERS ]]; then
-      ZOO_SERVERS="server.1=localhost:2888:3888;2181"
-    fi
-
-    for server in $ZOO_SERVERS; do
-        echo "$server" >> "$CONFIG"
-    done
-
-    if [[ -n $ZOO_4LW_COMMANDS_WHITELIST ]]; then
-        echo "4lw.commands.whitelist=$ZOO_4LW_COMMANDS_WHITELIST" >> "$CONFIG"
-    fi
-
-fi
-
-# Write myid only if it doesn't exist
-if [[ ! -f "$ZOO_DATA_DIR/myid" ]]; then
-    echo "${ZOO_MY_ID:-1}" > "$ZOO_DATA_DIR/myid"
-fi
-
-exec "$@"

zookeeper/sources.list

+# deb cdrom:[Ubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)]/ bionic main restricted
+deb-src http://archive.ubuntu.com/ubuntu bionic main restricted #Added by software-properties
+deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted
+deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted multiverse universe #Added by software-properties
+deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted
+deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted multiverse universe #Added by software-properties
+deb http://mirrors.aliyun.com/ubuntu/ bionic universe
+deb http://mirrors.aliyun.com/ubuntu/ bionic-updates universe
+deb http://mirrors.aliyun.com/ubuntu/ bionic multiverse
+deb http://mirrors.aliyun.com/ubuntu/ bionic-updates multiverse
+deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
+deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse #Added by software-properties
+deb http://archive.canonical.com/ubuntu bionic partner
+deb-src http://archive.canonical.com/ubuntu bionic partner
+deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted
+deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted multiverse universe #Added by software-properties
+deb http://mirrors.aliyun.com/ubuntu/ bionic-security universe
+deb http://mirrors.aliyun.com/ubuntu/ bionic-security multiverse
+

zookeeper/zkGenConfig.sh

+#!/usr/bin/env bash
+# Copyright 2016 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+ZK_USER=${ZK_USER:-"zookeeper"}
+ZK_LOG_LEVEL=${ZK_LOG_LEVEL:-"INFO"}
+ZK_DATA_DIR=${ZK_DATA_DIR:-"/var/lib/zookeeper/data"}
+ZK_DATA_LOG_DIR=${ZK_DATA_LOG_DIR:-"/var/lib/zookeeper/log"}
+ZK_LOG_DIR=${ZK_LOG_DIR:-"var/log/zookeeper"}
+ZK_CONF_DIR=${ZK_CONF_DIR:-"/opt/zookeeper/conf"}
+ZK_CLIENT_PORT=${ZK_CLIENT_PORT:-2181}
+ZK_SERVER_PORT=${ZK_SERVER_PORT:-2888}
+ZK_ELECTION_PORT=${ZK_ELECTION_PORT:-3888}
+ZK_TICK_TIME=${ZK_TICK_TIME:-2000}
+ZK_INIT_LIMIT=${ZK_INIT_LIMIT:-10}
+ZK_SYNC_LIMIT=${ZK_SYNC_LIMIT:-5}
+ZK_HEAP_SIZE=${ZK_HEAP_SIZE:-2G}
+ZK_JVM_OPTS=${ZK_JVM_OPTS:-}
+ZK_MAX_CLIENT_CNXNS=${ZK_MAX_CLIENT_CNXNS:-60}
+ZK_MIN_SESSION_TIMEOUT=${ZK_MIN_SESSION_TIMEOUT:- $((ZK_TICK_TIME*2))}
+ZK_MAX_SESSION_TIMEOUT=${ZK_MAX_SESSION_TIMEOUT:- $((ZK_TICK_TIME*20))}
+ZK_SNAP_RETAIN_COUNT=${ZK_SNAP_RETAIN_COUNT:-3}
+ZK_PURGE_INTERVAL=${ZK_PURGE_INTERVAL:-0}
+ID_FILE="$ZK_DATA_DIR/myid"
+ZK_CONFIG_FILE="$ZK_CONF_DIR/zoo.cfg"
+LOGGER_PROPS_FILE="$ZK_CONF_DIR/log4j.properties"
+JAVA_ENV_FILE="$ZK_CONF_DIR/java.env"
+HOST=`hostname -s`
+DOMAIN=`hostname -d`
+
+function print_servers() {
+    for (( i=1; i<=$ZK_REPLICAS; i++ ))
+    do
+        echo "server.$i=$NAME-$((i-1)).$DOMAIN:$ZK_SERVER_PORT:$ZK_ELECTION_PORT"
+    done
+}
+
+function validate_env() {
+    echo "Validating environment"
+
+    if [ -z $ZK_REPLICAS ]; then
+        echo "ZK_REPLICAS is a mandatory environment variable"
+        exit 1
+    fi
+
+    if [[ $HOST =~ (.*)-([0-9]+)$ ]]; then
+        NAME=${BASH_REMATCH[1]}
+        ORD=${BASH_REMATCH[2]}
+    else
+        echo "Failed to extract ordinal from hostname $HOST"
+        exit 1
+    fi
+
+    MY_ID=$((ORD+1))
+    echo "ZK_REPLICAS=$ZK_REPLICAS"
+    echo "MY_ID=$MY_ID"
+    echo "ZK_LOG_LEVEL=$ZK_LOG_LEVEL"
+    echo "ZK_DATA_DIR=$ZK_DATA_DIR"
+    echo "ZK_DATA_LOG_DIR=$ZK_DATA_LOG_DIR"
+    echo "ZK_LOG_DIR=$ZK_LOG_DIR"
+    echo "ZK_CLIENT_PORT=$ZK_CLIENT_PORT"
+    echo "ZK_SERVER_PORT=$ZK_SERVER_PORT"
+    echo "ZK_ELECTION_PORT=$ZK_ELECTION_PORT"
+    echo "ZK_TICK_TIME=$ZK_TICK_TIME"
+    echo "ZK_INIT_LIMIT=$ZK_INIT_LIMIT"
+    echo "ZK_SYNC_LIMIT=$ZK_SYNC_LIMIT"
+    echo "ZK_MAX_CLIENT_CNXNS=$ZK_MAX_CLIENT_CNXNS"
+    echo "ZK_MIN_SESSION_TIMEOUT=$ZK_MIN_SESSION_TIMEOUT"
+    echo "ZK_MAX_SESSION_TIMEOUT=$ZK_MAX_SESSION_TIMEOUT"
+    echo "ZK_HEAP_SIZE=$ZK_HEAP_SIZE"
+    echo "ZK_SNAP_RETAIN_COUNT=$ZK_SNAP_RETAIN_COUNT"
+    echo "ZK_PURGE_INTERVAL=$ZK_PURGE_INTERVAL"
+    echo "ZK_JVM_OPTS=$ZK_JVM_OPTS"
+    echo "ENSEMBLE"
+    print_servers
+    echo "Environment validation successful"
+}
+
+function create_config() {
+    rm -f $ZK_CONFIG_FILE
+    echo "Creating ZooKeeper configuration"
+    echo "#This file was autogenerated by k8szk DO NOT EDIT" >> $ZK_CONFIG_FILE
+    echo "clientPort=$ZK_CLIENT_PORT" >> $ZK_CONFIG_FILE
+    echo "dataDir=$ZK_DATA_DIR" >> $ZK_CONFIG_FILE
+    echo "dataLogDir=$ZK_DATA_LOG_DIR" >> $ZK_CONFIG_FILE
+    echo "tickTime=$ZK_TICK_TIME" >> $ZK_CONFIG_FILE
+    echo "initLimit=$ZK_INIT_LIMIT" >> $ZK_CONFIG_FILE
+    echo "syncLimit=$ZK_SYNC_LIMIT" >> $ZK_CONFIG_FILE
+    echo "maxClientCnxns=$ZK_MAX_CLIENT_CNXNS" >> $ZK_CONFIG_FILE
+    echo "minSessionTimeout=$ZK_MIN_SESSION_TIMEOUT" >> $ZK_CONFIG_FILE
+    echo "maxSessionTimeout=$ZK_MAX_SESSION_TIMEOUT" >> $ZK_CONFIG_FILE
+    echo "autopurge.snapRetainCount=$ZK_SNAP_RETAIN_COUNT" >> $ZK_CONFIG_FILE
+    echo "autopurge.purgeInterval=$ZK_PURGE_INTERVAL" >> $ZK_CONFIG_FILE
+
+    if [ $ZK_REPLICAS -gt 1 ]; then
+        print_servers >> $ZK_CONFIG_FILE
+    fi
+
+    echo "Wrote ZooKeeper configuration file to $ZK_CONFIG_FILE"
+}
+
+function create_data_dirs() {
+    echo "Creating ZooKeeper data directories and setting permissions"
+
+    if [ ! -d $ZK_DATA_DIR  ]; then
+        mkdir -p $ZK_DATA_DIR
+        chown -R $ZK_USER:$ZK_USER $ZK_DATA_DIR
+    fi
+
+    if [ ! -d $ZK_DATA_LOG_DIR  ]; then
+        mkdir -p $ZK_DATA_LOG_DIR
+        chown -R $ZK_USER:$ZK_USER $ZK_DATA_LOG_DIR
+    fi
+
+    if [ ! -d $ZK_LOG_DIR  ]; then
+        mkdir -p $ZK_LOG_DIR
+        chown -R $ZK_USER:$ZK_USER $ZK_LOG_DIR
+    fi
+
+    if [ ! -f $ID_FILE ]; then
+        echo $MY_ID >> $ID_FILE
+    fi
+
+    echo "Created ZooKeeper data directories and set permissions in $ZK_DATA_DIR"
+}
+
+function create_log_props () {
+    rm -f $LOGGER_PROPS_FILE
+    echo "Creating ZooKeeper log4j configuration"
+    echo "zookeeper.root.logger=CONSOLE" >> $LOGGER_PROPS_FILE
+    echo "zookeeper.console.threshold="$ZK_LOG_LEVEL >> $LOGGER_PROPS_FILE
+    echo "log4j.rootLogger=\${zookeeper.root.logger}" >> $LOGGER_PROPS_FILE
+    echo "log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender" >> $LOGGER_PROPS_FILE
+    echo "log4j.appender.CONSOLE.Threshold=\${zookeeper.console.threshold}" >> $LOGGER_PROPS_FILE
+    echo "log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout" >> $LOGGER_PROPS_FILE
+    echo "log4j.appender.CONSOLE.layout.ConversionPattern=%d{ISO8601} [myid:%X{myid}] - %-5p [%t:%C{1}@%L] - %m%n" >> $LOGGER_PROPS_FILE
+    echo "Wrote log4j configuration to $LOGGER_PROPS_FILE"
+}
+
+function create_java_env() {
+    rm -f $JAVA_ENV_FILE
+    echo "Creating JVM configuration file"
+    echo "ZOO_LOG_DIR=$ZK_LOG_DIR" >> $JAVA_ENV_FILE
+    echo "JVMFLAGS=\"-Xmx$ZK_HEAP_SIZE -Xms$ZK_HEAP_SIZE $ZK_JVM_OPTS\"" >> $JAVA_ENV_FILE
+    echo "Wrote JVM configuration to $JAVA_ENV_FILE"
+}
+
+validate_env && create_config && create_log_props && create_data_dirs && create_java_env

zookeeper/zkMetrics.sh

+#!/usr/bin/env bash
+# Copyright 2016 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+ZK_CLIENT_PORT=${ZK_CLIENT_PORT:-2181}
+echo mntr | nc localhost $ZK_CLIENT_PORT >& 1

zookeeper/zkOk.sh

+#!/usr/bin/env bash
+# Copyright 2016 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# zkOk.sh uses the ruok ZooKeeper four letter work to determine if the instance
+# is health. The $? variable will be set to 0 if server responds that it is 
+# healthy, or 1 if the server fails to respond.
+
+ZK_CLIENT_PORT=${ZK_CLIENT_PORT:-2181}
+OK=$(echo ruok | nc 127.0.0.1 $ZK_CLIENT_PORT)
+if [ "$OK" == "imok" ]; then
+	exit 0
+else
+	exit 1
+fi
\ No newline at end of file

zookeeper/zookeeper.yaml

+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: zk-svc
+  labels:
+    app: zk-svc
+spec:
+  ports:
+  - port: 2888
+    name: server
+  - port: 3888
+    name: leader-election
+  clusterIP: None
+  selector:
+    app: zk
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: zk-cm
+data:
+  jvm.heap: "1G"
+  tick: "2000"
+  init: "10"
+  sync: "5"
+  client.cnxns: "60"
+  snap.retain: "3"
+  purge.interval: "0"
+---
+apiVersion: policy/v1beta1
+kind: PodDisruptionBudget
+metadata:
+  name: zk-pdb
+spec:
+  selector:
+    matchLabels:
+      app: zk
+  minAvailable: 2
+---
+apiVersion: apps/v1beta1
+kind: StatefulSet
+metadata:
+  name: zk
+spec:
+  serviceName: zk-svc
+  replicas: 3
+  template:
+    metadata:
+      labels:
+        app: zk
+    spec:
+      affinity:
+        podAntiAffinity:
+          requiredDuringSchedulingIgnoredDuringExecution:
+            - labelSelector:
+                matchExpressions:
+                  - key: "app"
+                    operator: In
+                    values: 
+                    - zk
+              topologyKey: "kubernetes.io/hostname"
+      containers:
+      - name: k8szk
+        imagePullPolicy: Always
+        image: gcr.io/google_samples/k8szk:v3
+        resources:
+          requests:
+            memory: "2Gi"
+            cpu: "500m"
+        ports:
+        - containerPort: 2181
+          name: client
+        - containerPort: 2888
+          name: server
+        - containerPort: 3888
+          name: leader-election
+        env:
+        - name : ZK_REPLICAS
+          value: "3"
+        - name : ZK_HEAP_SIZE
+          valueFrom:
+            configMapKeyRef:
+                name: zk-cm
+                key: jvm.heap
+        - name : ZK_TICK_TIME
+          valueFrom:
+            configMapKeyRef:
+                name: zk-cm
+                key: tick
+        - name : ZK_INIT_LIMIT
+          valueFrom:
+            configMapKeyRef:
+                name: zk-cm
+                key: init
+        - name : ZK_SYNC_LIMIT
+          valueFrom:
+            configMapKeyRef:
+                name: zk-cm
+                key: tick
+        - name : ZK_MAX_CLIENT_CNXNS
+          valueFrom:
+            configMapKeyRef:
+                name: zk-cm
+                key: client.cnxns
+        - name: ZK_SNAP_RETAIN_COUNT
+          valueFrom:
+            configMapKeyRef:
+                name: zk-cm
+                key: snap.retain
+        - name: ZK_PURGE_INTERVAL
+          valueFrom:
+            configMapKeyRef:
+                name: zk-cm
+                key: purge.interval
+        - name: ZK_CLIENT_PORT
+          value: "2181"
+        - name: ZK_SERVER_PORT
+          value: "2888"
+        - name: ZK_ELECTION_PORT
+          value: "3888"
+        command:
+        - sh
+        - -c
+        - zkGenConfig.sh && zkServer.sh start-foreground
+        readinessProbe:
+          exec:
+            command:
+            - "zkOk.sh"
+          initialDelaySeconds: 10
+          timeoutSeconds: 5
+        livenessProbe:
+          exec:
+            command:
+            - "zkOk.sh"
+          initialDelaySeconds: 10
+          timeoutSeconds: 5
+        volumeMounts:
+        - name: datadir
+          mountPath: /var/lib/zookeeper
+      securityContext:
+        runAsUser: 1000
+        fsGroup: 1000
+  volumeClaimTemplates:
+  - metadata:
+      name: datadir
+    spec:
+      accessModes: [ "ReadWriteOnce" ]
+      resources:
+        requests:
+          storage: 10Gi