106 lines
4.1 KiB
Bash
Executable file
106 lines
4.1 KiB
Bash
Executable file
#! /bin/bash
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# Copyright 2016 The Kubernetes Authors.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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set -eo pipefail
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# This script configures zookeeper cluster member ship for version of zookeeper
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# >= 3.5.0. It should not be used with the on-change.sh script in this example.
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# As of April-2016 is 3.4.8 is the latest stable.
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# Both /opt and /tmp/zookeeper are assumed to be volumes shared with the parent.
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# The format of each line in the dynamic config file is:
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# server.<1 based index>=<server-dns-name>:<peer port>:<election port>[:role];[<client port address>:]<client port>
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# <1 based index> is the server index that matches the id in datadir/myid
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# <peer port> is the port on which peers communicate to agree on updates
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# <election port> is the port used for leader election
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# [:role] can be set to observer, participant by default
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# <client port address> is optional and defaults to 0.0.0.0
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# <client port> is the port on which the server accepts client connections
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CFG=/opt/zookeeper/conf/zoo.cfg.dynamic
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CFG_BAK=/opt/zookeeper/conf/zoo.cfg.bak
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MY_ID_FILE=/tmp/zookeeper/myid
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HOSTNAME=$(hostname)
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while read -ra LINE; do
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PEERS=("${PEERS[@]}" $LINE)
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done
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# Don't add the first member as an observer
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if [ ${#PEERS[@]} -eq 1 ]; then
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# We need to write our index in this list of servers into MY_ID_FILE.
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# Note that this may not always coincide with the hostname id.
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echo 1 > "${MY_ID_FILE}"
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echo "server.1=${PEERS[0]}:2888:3888;2181" > "${CFG}"
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# TODO: zkServer-initialize is the safe way to handle changes to datadir
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# because simply starting will create a new datadir, BUT if the user changed
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# pod template they might end up with 2 datadirs and brief split brain.
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exit
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fi
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# Every subsequent member is added as an observer and promoted to a participant
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echo "" > "${CFG_BAK}"
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i=0
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LEADER=$HOSTNAME
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for peer in "${PEERS[@]}"; do
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let i=i+1
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if [[ "${peer}" == *"${HOSTNAME}"* ]]; then
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MY_ID=$i
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MY_NAME=${peer}
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echo $i > "${MY_ID_FILE}"
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echo "server.${i}=${peer}:2888:3888:observer;2181" >> "${CFG_BAK}"
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else
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if [[ $(echo srvr | /opt/nc "${peer}" 2181 | grep Mode) = "Mode: leader" ]]; then
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LEADER="${peer}"
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fi
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echo "server.${i}=${peer}:2888:3888:participant;2181" >> "${CFG_BAK}"
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fi
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done
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# zookeeper won't start without myid anyway.
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# This means our hostname wasn't in the peer list.
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if [ ! -f "${MY_ID_FILE}" ]; then
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exit 1
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fi
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# Once the dynamic config file is written it shouldn't be modified, so the final
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# reconfigure needs to happen through the "reconfig" command.
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cp ${CFG_BAK} ${CFG}
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# TODO: zkServer-initialize is the safe way to handle changes to datadir
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# because simply starting will create a new datadir, BUT if the user changed
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# pod template they might end up with 2 datadirs and brief split brain.
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/opt/zookeeper/bin/zkServer.sh start
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# TODO: We shouldn't need to specify the address of the master as long as
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# there's quorum. According to the docs the new server is just not allowed to
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# vote, it's still allowed to propose config changes, and it knows the
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# existing members of the ensemble from *its* config.
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ADD_SERVER="server.$MY_ID=$MY_NAME:2888:3888:participant;0.0.0.0:2181"
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/opt/zookeeper/bin/zkCli.sh reconfig -s "${LEADER}":2181 -add "${ADD_SERVER}"
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# Prove that we've actually joined the running cluster
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ITERATION=0
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until $(echo config | /opt/nc localhost 2181 | grep "${ADD_SERVER}" > /dev/null); do
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echo $ITERATION] waiting for updated config to sync back to localhost
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sleep 1
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let ITERATION=ITERATION+1
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if [ $ITERATION -eq 20 ]; then
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exit 1
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fi
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done
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/opt/zookeeper/bin/zkServer.sh stop
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