Current from https://github.com/kubernetes/contrib/tree/master/pets

8 files changed, 481 insertions, 0 deletions

diff --git a/zookeeper/README.md b/zookeeper/README.md
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+# Zookeeper
+
+This example runs zookeeper through a petset.
+
+## Bootstrap
+
+Create the petset in this directory
+```
+$ kubetl create -f zookeeper.yaml
+```
+
+Once you have all 3 nodes in Running, you can run the "test.sh" script in this directory.
+
+## Failover
+
+You can test failover by killing the leader. Insert a key:
+```console
+$ kubectl exec zoo-0 -- /opt/zookeeper/bin/zkCli.sh create /foo bar;
+$ kubectl exec zoo-2 -- /opt/zookeeper/bin/zkCli.sh get /foo;
+
+Watch existing members:
+```console
+$ kubectl run --attach bbox --image=busybox --restart=Never -- sh -c 'while true; do for i in 0 1 2; do echo zoo-$i $(echo stats | nc zoo-$i.zk:2181 | grep Mode); sleep 1; done; done';
+zoo-2 Mode: follower
+zoo-0 Mode: follower
+zoo-1 Mode: leader
+zoo-2 Mode: follower
+```
+
+Delete pets and wait for the petset controller to bring the back up:
+```console
+$ kubectl delete po -l app=zk
+$ kubectl get po --watch-only
+NAME      READY     STATUS     RESTARTS   AGE
+zoo-0     0/1       Init:0/2   0          16s
+zoo-0     0/1       Init:0/2   0         21s
+zoo-0     0/1       PodInitializing   0         23s
+zoo-0     1/1       Running   0         41s
+zoo-1     0/1       Pending   0         0s
+zoo-1     0/1       Init:0/2   0         0s
+zoo-1     0/1       Init:0/2   0         14s
+zoo-1     0/1       PodInitializing   0         17s
+zoo-1     0/1       Running   0         18s
+zoo-2     0/1       Pending   0         0s
+zoo-2     0/1       Init:0/2   0         0s
+zoo-2     0/1       Init:0/2   0         12s
+zoo-2     0/1       Init:0/2   0         28s
+zoo-2     0/1       PodInitializing   0         31s
+zoo-2     0/1       Running   0         32s
+...
+
+zoo-0 Mode: follower
+zoo-1 Mode: leader
+zoo-2 Mode: follower
+```
+
+Check the previously inserted key:
+```console
+$ kubectl exec zoo-1 -- /opt/zookeeper/bin/zkCli.sh get /foo
+ionid = 0x354887858e80035, negotiated timeout = 30000
+
+WATCHER::
+
+WatchedEvent state:SyncConnected type:None path:null
+bar
+```
+
+## Scaling
+
+You can scale up by modifying the number of replicas on the PetSet.
+
+## Image Upgrade
+
+TODO: Add details
+
+## Maintenance
+
+TODO: Add details
+
+## Limitations
+* Both petset and init containers are in alpha
+* Look through the on-start and on-change scripts for TODOs
+* Doesn't support the addition of observers through the petset
+* Only supports storage options that have backends for persistent volume claims
+
diff --git a/zookeeper/init/Dockerfile b/zookeeper/init/Dockerfile
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+# Copyright 2016 The Kubernetes Authors All rights reserved.
+#
+# 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.
+
+# TODO: get rid of bash dependency and switch to plain busybox.
+# The tar in busybox also doesn't seem to understand compression.
+FROM debian:jessie
+MAINTAINER Prashanth.B <beeps@google.com>
+
+RUN apt-get update && apt-get install -y wget netcat
+
+ADD on-start.sh /
+ADD on-change.sh /
+# See contrib/pets/peer-finder for details
+RUN wget -qO /peer-finder https://storage.googleapis.com/kubernetes-release/pets/peer-finder
+
+ADD install.sh /
+RUN chmod -c 755 /install.sh /on-start.sh /on-change.sh /peer-finder
+Entrypoint ["/install.sh"]
diff --git a/zookeeper/init/Makefile b/zookeeper/init/Makefile
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+# Copyright 2016 The Kubernetes Authors All rights reserved.
+#
+# 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.
+
+all: push
+
+TAG = 0.1
+PREFIX = gcr.io/google_containers/zookeeper-install
+
+container:
+	docker build -t $(PREFIX):$(TAG) .
+
+push: container
+	gcloud docker push $(PREFIX):$(TAG)
+
+clean:
+	docker rmi $(PREFIX):$(TAG)
diff --git a/zookeeper/init/install.sh b/zookeeper/init/install.sh
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+#! /bin/bash
+
+# Copyright 2016 The Kubernetes Authors All rights reserved.
+#
+# 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.
+
+# This volume is assumed to exist and is shared with parent of the init
+# container. It contains the zookeeper installation.
+INSTALL_VOLUME="/opt"
+
+# This volume is assumed to exist and is shared with the peer-finder
+# init container. It contains on-start/change configuration scripts.
+WORKDIR_VOLUME="/work-dir"
+
+# As of April-2016 is 3.4.8 is the latest stable, but versions 3.5.0 onward
+# allow dynamic reconfiguration.
+VERSION="3.5.0-alpha"
+
+for i in "$@"
+do
+case $i in
+    -v=*|--version=*)
+    VERSION="${i#*=}"
+    shift
+    ;;
+    -i=*|--install-into=*)
+    INSTALL_VOLUME="${i#*=}"
+    shift
+    ;;
+    -w=*|--work-dir=*)
+    WORKDIR_VOLUME="${i#*=}"
+    shift
+    ;;
+    *)
+    # unknown option
+    ;;
+esac
+done
+
+echo installing config scripts into "${WORKDIR_VOLUME}"
+mkdir -p "${WORKDIR_VOLUME}"
+cp /on-start.sh "${WORKDIR_VOLUME}"/
+cp /on-change.sh "${WORKDIR_VOLUME}"/
+cp /peer-finder "${WORKDIR_VOLUME}"/
+
+echo installing zookeeper-"${VERSION}" into "${INSTALL_VOLUME}"
+mkdir -p "${INSTALL_VOLUME}"
+wget -q -O - http://apache.mirrors.pair.com/zookeeper/zookeeper-"${VERSION}"/zookeeper-"${VERSION}".tar.gz | tar -xzf - -C "${INSTALL_VOLUME}"
+mv "${INSTALL_VOLUME}"/zookeeper-"${VERSION}" "${INSTALL_VOLUME}"/zookeeper
+cp "${INSTALL_VOLUME}"/zookeeper/conf/zoo_sample.cfg "${INSTALL_VOLUME}"/zookeeper/conf/zoo.cfg
+
+# TODO: Should dynamic config be tied to the version?
+IFS="." read -ra RELEASE <<< "${VERSION}"
+if [ $(expr "${RELEASE[1]}") -gt 4 ]; then
+    echo zookeeper-"${VERSION}" supports dynamic reconfiguration, enabling it
+    echo "standaloneEnabled=false" >> "${INSTALL_VOLUME}"/zookeeper/conf/zoo.cfg
+    echo "dynamicConfigFile="${INSTALL_VOLUME}"/zookeeper/conf/zoo.cfg.dynamic" >> "${INSTALL_VOLUME}"/zookeeper/conf/zoo.cfg
+fi
+
+# TODO: This is a hack, netcat is convenient to have in the zookeeper container
+# I want to avoid using a custom zookeeper image just for this. So copy it.
+NC=$(which nc)
+if [ "${NC}" != "" ]; then
+    echo copying nc into "${INSTALL_VOLUME}"
+    cp "${NC}" "${INSTALL_VOLUME}"
+fi
diff --git a/zookeeper/init/on-change.sh b/zookeeper/init/on-change.sh
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+#! /bin/bash
+
+# Copyright 2016 The Kubernetes Authors All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This script configures zookeeper cluster member ship for version of zookeeper
+# < 3.5.0. It should not be used with the on-start.sh script in this example.
+# As of April-2016 is 3.4.8 is the latest stable.
+
+CFG=/opt/zookeeper/conf/zoo.cfg
+CFG_BAK=/opt/zookeeper/conf/zoo.cfg.bak
+MY_ID=/tmp/zookeeper/myid
+
+# write myid
+IFS='-' read -ra ADDR <<< "$(hostname)"
+echo $(expr "1" + "${ADDR[1]}") > "${MY_ID}"
+
+# TODO: This is a dumb way to reconfigure zookeeper because it allows dynamic
+# reconfig, but it's simple.
+i=0
+echo "
+tickTime=2000
+initLimit=10
+syncLimit=5
+dataDir=/tmp/zookeeper
+clientPort=2181
+" > "${CFG_BAK}"
+
+while read -ra LINE; do
+    let i=i+1
+    echo "server.${i}=${LINE}:2888:3888" >> "${CFG_BAK}"
+done
+cp ${CFG_BAK} ${CFG}
+
+# TODO: Typically one needs to first add a new member as an "observer" then
+# promote it to "participant", but that requirement is relaxed if we never
+# start > 1 at a time.
+/opt/zookeeper/bin/zkServer.sh restart
diff --git a/zookeeper/init/on-start.sh b/zookeeper/init/on-start.sh
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+#! /bin/bash
+
+# Copyright 2016 The Kubernetes Authors All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This script configures zookeeper cluster member ship for version of zookeeper
+# >= 3.5.0. It should not be used with the on-change.sh script in this example.
+# As of April-2016 is 3.4.8 is the latest stable.
+
+# Both /opt and /tmp/zookeeper are assumed to be volumes shared with the parent.
+CFG=/opt/zookeeper/conf/zoo.cfg.dynamic
+CFG_BAK=/opt/zookeeper/conf/zoo.cfg.bak
+MY_ID_FILE=/tmp/zookeeper/myid
+HOSTNAME=$(hostname)
+
+while read -ra LINE; do
+    PEERS=("${PEERS[@]}" $LINE)
+done
+
+# Don't add the first member as an observer
+if [ ${#PEERS[@]} -eq 1 ]; then
+    # We need to write our index in this list of servers into MY_ID_FILE.
+    # Note that this may not always coincide with the hostname id.
+    echo 1 > "${MY_ID_FILE}"
+    echo "server.1=${PEERS[0]}:2888:3888;2181" > "${CFG}"
+    # TODO: zkServer-initialize is the safe way to handle changes to datadir
+    # because simply starting will create a new datadir, BUT if the user changed
+    # pod template they might end up with 2 datadirs and brief split brain.
+    exit
+fi
+
+# Every subsequent member is added as an observer and promoted to a participant
+echo "" > "${CFG_BAK}"
+i=0
+for peer in "${PEERS[@]}"; do
+    let i=i+1
+    if [[ "${peer}" == *"${HOSTNAME}"* ]]; then
+      MY_ID=$i
+      MY_NAME=${peer}
+      echo $i > "${MY_ID_FILE}"
+      echo "server.${i}=${peer}:2888:3888:observer;2181" >> "${CFG_BAK}"
+    else
+      echo "server.${i}=${peer}:2888:3888:participant;2181" >> "${CFG_BAK}"
+    fi
+done
+
+# Once the dynamic config file is written it shouldn't be modified, so the final
+# reconfigure needs to happen through the "reconfig" command.
+cp ${CFG_BAK} ${CFG}
+
+# TODO: zkServer-initialize is the safe way to handle changes to datadir
+# because simply starting will create a new datadir, BUT if the user changed
+# pod template they might end up with 2 datadirs and brief split brain.
+/opt/zookeeper/bin/zkServer.sh start
+
+# TODO: We shouldn't need to specify the address of the master as long as
+# there's quorum. According to the docs the new server is just not allowed to
+# vote, it's still allowed to propose config changes, and it knows the
+# existing members of the ensemble from *its* config. This works as expected,
+# but we should correlate with more satisfying empirical evidence.
+/opt/zookeeper/bin/zkCli.sh reconfig -add "server.$MY_ID=$MY_NAME:2888:3888:participant;2181"
+/opt/zookeeper/bin/zkServer.sh stop
diff --git a/zookeeper/test.sh b/zookeeper/test.sh
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+#! /bin/bash
+
+# Copyright 2016 The Kubernetes Authors All rights reserved.
+#
+# 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.
+
+kubectl exec zoo-0 -- /opt/zookeeper/bin/zkCli.sh create /foo bar;
+kubectl exec zoo-2 -- /opt/zookeeper/bin/zkCli.sh get /foo;
+
diff --git a/zookeeper/zookeeper.yaml b/zookeeper/zookeeper.yaml
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+# A headless service to create DNS records
+apiVersion: v1
+kind: Service
+metadata:
+  annotations:
+    service.alpha.kubernetes.io/tolerate-unready-endpoints: "true"
+  name: zk
+  labels:
+    app: zk
+spec:
+  ports:
+  - port: 2888
+    name: peer
+  - port: 3888
+    name: leader-election
+  # *.zk.default.svc.cluster.local
+  clusterIP: None
+  selector:
+    app: zk
+---
+apiVersion: apps/v1alpha1
+kind: PetSet
+metadata:
+  name: zoo
+spec:
+  serviceName: "zk"
+  replicas: 3
+  template:
+    metadata:
+      labels:
+        app: zk
+      annotations:
+        pod.alpha.kubernetes.io/initialized: "true"
+        pod.alpha.kubernetes.io/init-containers: '[
+            {
+                "name": "install",
+                "image": "gcr.io/google_containers/zookeeper-install:0.1",
+                "imagePullPolicy": "Always",
+                "args": ["--version=3.5.0-alpha", "--install-into=/opt", "--work-dir=/work-dir"],
+                "volumeMounts": [
+                    {
+                        "name": "opt",
+                        "mountPath": "/opt/"
+                    },
+                    {
+                        "name": "workdir",
+                        "mountPath": "/work-dir"
+                    }
+                ]
+            },
+            {
+                "name": "bootstrap",
+                "image": "java:openjdk-8-jre",
+                "command": ["/work-dir/peer-finder"],
+                "args": ["-on-start=\"/work-dir/on-start.sh\"", "-service=zk"],
+                "env": [
+                  {
+                      "name": "POD_NAMESPACE",
+                      "valueFrom": {
+                          "fieldRef": {
+                              "apiVersion": "v1",
+                              "fieldPath": "metadata.namespace"
+                          }
+                      }
+                   }
+                ],
+                "volumeMounts": [
+                    {
+                        "name": "opt",
+                        "mountPath": "/opt/"
+                    },
+                    {
+                        "name": "workdir",
+                        "mountPath": "/work-dir"
+                    },
+                    {
+                        "name": "datadir",
+                        "mountPath": "/tmp/zookeeper"
+                    }
+                ]
+            }
+        ]'
+    spec:
+      containers:
+      - name: zk
+        image: java:openjdk-8-jre
+        ports:
+        - containerPort: 2888
+          name: peer
+        - containerPort: 3888
+          name: leader-election
+        command:
+        - /opt/zookeeper/bin/zkServer.sh
+        args:
+        - start-foreground
+        readinessProbe:
+          exec:
+            command:
+            - sh
+            - -c
+            - "/opt/zookeeper/bin/zkCli.sh ls /"
+          initialDelaySeconds: 15
+          timeoutSeconds: 5
+        volumeMounts:
+        - name: datadir
+          mountPath: /tmp/zookeeper
+        - name: opt
+          mountPath: /opt/
+      volumes:
+      - name: opt
+        emptyDir: {}
+      - name: workdir
+        emptyDir: {}
+  volumeClaimTemplates:
+  - metadata:
+      name: datadir
+      annotations:
+        volume.alpha.kubernetes.io/storage-class: anything
+    spec:
+      accessModes: [ "ReadWriteOnce" ]
+      resources:
+        requests:
+          storage: 20Gi