create-cluster script added.

Simple shell script to create / destroy Redis clusters for manual
testing.

utils/create-cluster/README

@@ -0,0 +1,27 @@
+Create-custer is a small script used to easily start a big number of Redis
+instances configured to run in cluster mode. Its main goal is to allow manual
+testing in a condition which is not easy to replicate with the Redis cluster
+unit tests, for example when a lot of instances are needed in order to trigger
+a give bug.
+
+The tool can also be used just to easily create a number of instances in a
+Redis Cluster in order to experiment a bit with the system.
+
+USAGE
+---
+
+To create a cluster, follow this steps:
+
+1. Edit create-cluster and change the start / end port, depending on the
+number of instances you want to create.
+2. Use "./create-cluster start" in order to run the instances.
+3. Use "./create-cluster create" in order to execute redis-trib create, so that
+an actual Redis cluster will be created.
+4. Now you are ready to play with the cluster. AOF files and logs for each instances are created in the current directory.
+
+In order to stop a cluster:
+
+1. Use "./craete-cluster stop" to stop all the instances. After you stopped the instances you can use "./create-cluster start" to restart them if you change ideas.
+2. Use "./create-cluster clean" to remove all the AOF / log files to restat with a clean environment.
+
+It is currently hardcoded that you start a cluster where each master has one slave, since the script is pretty basic.

utils/create-cluster/create-cluster

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+#!/bin/bash
+
+PORT=30000
+ENDPORT=30006
+
+if [ "$1" == "start" ]
+then
+    while [ $((PORT < ENDPORT)) != "0" ]; do
+        PORT=$((PORT+1))
+        echo "Starting $PORT"
+        ../../src/redis-server --port $PORT --cluster-enabled yes --cluster-config-file nodes-${PORT}.conf --cluster-node-timeout 5 --appendonly yes --appendfilename appendonly-${PORT}.aof --dbfilename dump-${PORT}.rdb --logfile ${PORT}.log --daemonize yes
+    done
+    exit 0
+fi
+
+if [ "$1" == "create" ]
+then
+    HOSTS=""
+    while [ $((PORT < ENDPORT)) != "0" ]; do
+        PORT=$((PORT+1))
+        HOSTS="$HOSTS 127.0.0.1:$PORT"
+    done
+    ../../src/redis-trib.rb create --replicas 1 $HOSTS
+    exit 0
+fi
+
+if [ "$1" == "stop" ]
+then
+    while [ $((PORT < ENDPORT)) != "0" ]; do
+        PORT=$((PORT+1))
+        echo "Stopping $PORT"
+        redis-cli -p $PORT shutdown nosave
+    done
+    exit 0
+fi
+
+if [ "$1" == "join" ]
+then
+    while [ $((PORT < ENDPORT)) != "0" ]; do
+        PORT=$((PORT+1))
+        echo "Joining $PORT"
+        redis-cli -p $PORT CLUSTER MEET 127.0.0.1 10002
+    done
+
+    echo "Waiting 5 seconds"
+    sleep 5
+
+    PORT=30000
+    while [ $((PORT < ENDPORT)) != "0" ]; do
+        PORT=$((PORT+1))
+        echo "Replicate $PORT"
+        redis-cli -p $PORT CLUSTER REPLICATE $2 
+    done
+    exit 0
+fi
+
+if [ "$1" == "clean" ]
+then
+    rm -rf *.log
+    rm -rf appendonly*.aof
+    rm -rf dump*.rdb
+    rm -rf nodes*.conf
+    exit 0
+fi
+
+echo "Usage: $0 [start|create|stop|join|clean]"