HOSTS:
  centos-6-x64:
    roles:
      - master
      - database
      - dashboard
    platform: el-6-x86_64
    image: centos:6.7
    hypervisor: docker
    docker_cmd: ["/sbin/init"]
    docker_preserve_image: true
    docker_image_commands:
      - yum install -y wget tar which java-1.8.0-openjdk-headless
      - rm /etc/init/tty.conf
      - echo -e "elasticsearch hard nproc 4096\nelasticsearch soft nproc 4096" >> /etc/security/limits.conf
CONFIG:
  log_level: warn

HOSTS:
  centos-6-x64:
    roles:
      - master
      - database
      - dashboard
    platform: el-6-x86_64
    image: centos:6.9
    hypervisor: docker
    docker_cmd: ["/sbin/init"]
    docker_preserve_image: true
    docker_image_commands:
      - yum install -y wget tar which java-1.8.0-openjdk-headless
      - rm /etc/init/tty.conf
      - echo -e "elasticsearch hard nproc 4096\nelasticsearch soft nproc 4096" >> /etc/security/limits.conf
CONFIG:
  log_level: warn

Update centos 6 image tag to 6.9
Update centos 6 image tag to 6.9
