PetSet examples

examples/pets/README.md

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+# PetSet examples
+
+These examples are tracked from the [Kubernetes contrib project @d6e4be](https://github.com/kubernetes/contrib/tree/d6e4be066cc076fbb91ff69691819e117711b30b/pets)

examples/pets/mysql/galera/README.md

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+# Mysql Galera
+
+This example runs mysql galera through a petset.
+
+## Bootstrap
+
+Create the petset in this directory
+```
+$ kubectl create -f galera.yaml
+```
+
+Once you have all 3 nodes in Running, you can run the "test.sh" script in this directory.
+This example requires manual intervention.
+Once you have all 3 nodes in Running, you can run the "test.sh" script in this directory.
+
+## Caveats
+
+Starting up all galera nodes at once leads to an issue where all the mysqls
+belive they're in the primary component because they don't see the others in
+the DNS. For the bootstrapping to work: mysql-0 needs to see itself, mysql-1
+needs to see itself and mysql-0, and so on, because the first node that sees
+a peer list of 1 will assume it's the leader.
+
+## TODO
+
+Expect better solutions for the following as petset matures.
+
+* Failover
+* Scaling Up
+* Scaling Down
+* Image Upgrade
+* Maintenance
+

examples/pets/mysql/galera/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
+
+ADD on-start.sh /
+ADD my-galera.cnf /
+# 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 /peer-finder
+Entrypoint ["/install.sh"]

examples/pets/mysql/galera/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/galera-install
+
+container:
+	docker build -t $(PREFIX):$(TAG) .
+
+push: container
+	gcloud docker push $(PREFIX):$(TAG)
+
+clean:
+	docker rmi $(PREFIX):$(TAG)

examples/pets/mysql/galera/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 mysq config.
+CONFIG_VOLUME="/etc/mysql"
+
+# 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"
+
+for i in "$@"
+do
+case $i in
+    -c=*|--config=*)
+    CONFIG_VOLUME="${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 /peer-finder "${WORKDIR_VOLUME}"/
+
+echo installing my-galera.cnf into "${CONFIG_VOLUME}"
+mkdir -p "${CONFIG_VOLUME}"
+chown -R mysql:mysql "${CONFIG_VOLUME}"
+cp /my-galera.cnf "${CONFIG_VOLUME}"/

examples/pets/mysql/galera/init/my-galera.cnf

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+[mysqld]
+user = mysql
+bind-address = 0.0.0.0
+wsrep_provider = /usr/lib/galera/libgalera_smm.so
+# TODO: is rsync the best option?
+wsrep_sst_method = rsync
+default_storage_engine = innodb
+binlog_format = row
+innodb_autoinc_lock_mode = 2
+innodb_flush_log_at_trx_commit = 0
+query_cache_size = 0
+query_cache_type = 0
+
+# By default every node is standalone
+wsrep_cluster_address=gcomm://
+wsrep_cluster_name=galera
+wsrep_node_address=127.0.0.1
+
+# TODO: Enable use privileges. This doesn't work
+# on mysql restart, for some reason after the SST
+# permissions are not setup correctly.
+skip-grant-tables

examples/pets/mysql/galera/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 writes out a mysql galera config using a list of newline seperated
+# peer DNS names it accepts through stdin.
+
+# /etc/mysql is assumed to be a shared volume so we can modify my.cnf as required
+# to keep the config up to date, without wrapping mysqld in a custom pid1.
+# The config location is intentionally not /etc/mysql/my.cnf because the
+# standard base image clobbers that location.
+CFG=/etc/mysql/my-galera.cnf
+
+function join {
+    local IFS="$1"; shift; echo "$*";
+}
+
+HOSTNAME=$(hostname)
+# Parse out cluster name, formatted as: petset_name-index
+IFS='-' read -ra ADDR <<< "$(hostname)"
+CLUSTER_NAME="${ADDR[0]}"
+
+while read -ra LINE; do
+    if [[ "${LINE}" == *"${HOSTNAME}"* ]]; then
+        MY_NAME=$LINE
+    fi
+    PEERS=("${PEERS[@]}" $LINE)
+done
+
+if [ "${#PEERS[@]}" = 1 ]; then
+    WSREP_CLUSTER_ADDRESS=""
+else
+    WSREP_CLUSTER_ADDRESS=$(join , "${PEERS[@]}")
+fi
+sed -i -e "s|^wsrep_node_address=.*$|wsrep_node_address=${MY_NAME}|" ${CFG}
+sed -i -e "s|^wsrep_cluster_name=.*$|wsrep_cluster_name=${CLUSTER_NAME}|" ${CFG}
+sed -i -e "s|^wsrep_cluster_address=.*$|wsrep_cluster_address=gcomm://${WSREP_CLUSTER_ADDRESS}|" ${CFG}
+
+# don't need a restart, we're just writing the conf in case there's an
+# unexpected restart on the node.

examples/pets/mysql/galera/mysql-galera.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: galera
+  labels:
+    app: mysql
+spec:
+  ports:
+  - port: 3306
+    name: mysql
+  # *.galear.default.svc.cluster.local
+  clusterIP: None
+  selector:
+    app: mysql
+---
+apiVersion: apps/v1alpha1
+kind: PetSet
+metadata:
+  name: mysql
+spec:
+  serviceName: "galera"
+  replicas: 3
+  template:
+    metadata:
+      labels:
+        app: mysql
+      annotations:
+        pod.alpha.kubernetes.io/initialized: "true"
+        pod.alpha.kubernetes.io/init-containers: '[
+            {
+                "name": "install",
+                "image": "gcr.io/google_containers/galera-install:0.1",
+                "imagePullPolicy": "Always",
+                "args": ["--work-dir=/work-dir"],
+                "volumeMounts": [
+                    {
+                        "name": "workdir",
+                        "mountPath": "/work-dir"
+                    },
+                    {
+                        "name": "config",
+                        "mountPath": "/etc/mysql"
+                    }
+                ]
+            },
+            {
+                "name": "bootstrap",
+                "image": "debian:jessie",
+                "command": ["/work-dir/peer-finder"],
+                "args": ["-on-start=\"/work-dir/on-start.sh\"", "-service=galera"],
+                "env": [
+                  {
+                      "name": "POD_NAMESPACE",
+                      "valueFrom": {
+                          "fieldRef": {
+                              "apiVersion": "v1",
+                              "fieldPath": "metadata.namespace"
+                          }
+                      }
+                   }
+                ],
+                "volumeMounts": [
+                    {
+                        "name": "workdir",
+                        "mountPath": "/work-dir"
+                    },
+                    {
+                        "name": "config",
+                        "mountPath": "/etc/mysql"
+                    }
+                ]
+            }
+        ]'
+    spec:
+      containers:
+      - name: mysql
+        image: erkules/galera:basic
+        ports:
+        - containerPort: 3306
+          name: mysql
+        - containerPort: 4444
+          name: sst
+        - containerPort: 4567
+          name: replication
+        - containerPort: 4568
+          name: ist
+        args:
+        - --defaults-file=/etc/mysql/my-galera.cnf
+        - --user=root
+        readinessProbe:
+          exec:
+            command:
+            - sh
+            - -c
+            - "mysql -u root -e 'show databases;'"
+          initialDelaySeconds: 15
+          timeoutSeconds: 5
+        volumeMounts:
+        - name: datadir
+          mountPath: /var/lib/
+        - name: config
+          mountPath: /etc/mysql
+      volumes:
+      - name: config
+        emptyDir: {}
+      - name: workdir
+        emptyDir: {}
+  volumeClaimTemplates:
+  - metadata:
+      name: datadir
+      annotations:
+        volume.alpha.kubernetes.io/storage-class: anything
+    spec:
+      accessModes: [ "ReadWriteOnce" ]
+      resources:
+        requests:
+          storage: 10Gi

examples/pets/mysql/galera/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 mysql-0 -- mysql -u root -e "create database test;"
+kubectl exec mysql-1 -- mysql -u root -e "use test; create table pet (id int(10), name varchar(20));"
+kubectl exec mysql-1 -- mysql -u root -e "use test; insert into pet (id, name) values (1, \"galera\");"
+kubectl exec mysql-2 -- mysql -u root -e "use test; select * from pet;"
+

examples/pets/mysql/healthz/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 mysql-client wget
+ADD mysql_healthz /mysql_healthz
+Entrypoint ["/mysql_healthz"]