rollStatefulset.sh

rollStatefulset.sh

#!/usr/bin/env bash

NAMESPACE=$1
STATEFULSET=$2
CONTAINER=$3
COMMAND=$4
GREP=$5

REPLICAS=$(kubectl -n $NAMESPACE get statefulset $STATEFULSET -o=jsonpath='{.status.currentReplicas}')

COUNT=$(($REPLICAS-1))
while [ $COUNT -gt -1 ]; do
    DELCMD=$(kubectl -n $NAMESPACE delete pod $STATEFULSET-$COUNT)
    echo $DELCMD
    STATUS="-1"
    while [ $STATUS -ne "0" ]; do
        TEST=$(kubectl -n $NAMESPACE exec -it -c $CONTAINER $STATEFULSET-$COUNT -- $COMMAND | grep $GREP)
        let STATUS=$?
        echo "$TEST - $STATUS"
        SLEEP 2
    done
    RESULT=$(kubectl -n $NAMESPACE get statefulset $STATEFULSET)
    let COUNT=COUNT-1
done

This is an attempt to do a controlled roll of a statefulset by deleting the pods in reverse order but allowing a check command to run so that the next pod is not rolled until some sort of ready state is reached - this requires kubectl to be intialized to a cluster before running.

ex. ./rollStatefulset.sh redis rfr-redis-hybris-dev redis "redis-cli role" "master\|slave"