cluster-helper.sh

#!/bin/bash


CLUSTER_CONTAINER_LIST+=($(docker ps -a -q))

# This function is used to display usage.
function usage
{
  echo -e "\nKafka Spinner Cluster operations usage\n"
  printf "%s\t%s\n" "--ip" "Print list of IP address and hostname on the cluster"  
  printf "%s\t\t\t%s\n" "--ssh" "SSH into any node of the cluster. eg: --ssh nodename"      
  printf "%s\t\t%s\n" "--help | -h" "Help"
  echo "--modify-hosts    modify hosts file of all nodes (eg: ----modify-hosts nodename)"  
}

function printClusterInfo
{
printf "%s\t%s\n" "HOSTNAME" "IP ADDRESS"
for i in "${CLUSTER_CONTAINER_LIST[@]}"
do
        printf "%s\t\t%s\n" "$(docker inspect -f '{{ .Config.Hostname }}' $i)" "$(docker inspect -f '{{ .NetworkSettings.IPAddress }}' $i)" 
done
}

function sshNode
{
ssh -o StrictHostKeyChecking=no root@$(docker inspect -f '{{ .NetworkSettings.IPAddress }}' $1)
}


function modifyHosts
{
  echo "Modifying /etc/hosts..."
  for i in "${CLUSTER_CONTAINER_LIST[@]}"
    do
            ssh -o StrictHostKeyChecking=no root@$(docker inspect -f "{{ .NetworkSettings.IPAddress }}" $i) "cp /etc/hosts /etc/hosts.bak && sed -e '/"$1"/s=^[0-9\.]*='"$(docker inspect -f '{{ .NetworkSettings.IPAddress }}' $1)"'=' /etc/hosts.bak > /etc/hosts"
    done

      for j in "${CLUSTER_CONTAINER_LIST[@]}"
        do
          ssh -o StrictHostKeyChecking=no root@$(docker inspect -f "{{ .NetworkSettings.IPAddress }}" $1) "echo '$(docker inspect -f "{{ .NetworkSettings.IPAddress }}" $j)   $(docker inspect -f '{{ .Config.Hostname }}' $j)'  >> /etc/hosts"
        done
}



while [ "$1" != "" ]; do
  case $1 in
    --ssh)                   shift
                             sshNode $1
                             ;;
    --ip)                    printClusterInfo
                             ;;
    --modify-hosts)          shift
                             modifyHosts $1
                             ;;
    -h | --help )            usage
                             exit
                             ;;
    * )                      usage
                             exit 1
  esac
  shift
done