update-domain.sh

#!/usr/bin/env bash
##
# Simle script to update domain resolve in OC masters
##

set -eu

AWS_PROFILE=""
HOSTED_ZONE_ID=""
DOMAIN=""
HOST_FILE_PATH=""
ANSIBLE_INVENTORY_PATH=""

function log() {
    # Sample logging
    stamp="$(date "+%Y-%m-%d %T")"
    echo -ne "${stamp} $@" >&2
}

function getDomainAlias() {
    # Get domain info from Route53, in this case it's alias
    domain_alias="$(aws route53 list-resource-record-sets --profile "${1}" --hosted-zone-id "${2}" \
            | jq -rc '.[][] | select(.Name == "'"${3}."'" and .Type == "'"A"'") | .AliasTarget.DNSName' \
            | sed 's/\.$//')";

    log "Geting details for ${3} form AWS zone ${2} using profile ${1}\n"
    log "Domain alias for ${3} is ${domain_alias}\n"
}

function getAliasIp() {
    # Get IPs of given alias using `host` command
    domain_ips="$(host -t A "${1}" | grep -Eo "[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}" | sed ':a;N;$!ba;s/\n/ /g')"
    log "IPs for alias ${1} are ${domain_ips}\n"
}

function updateIpsInStaticFiles() {
    # Update /etc/hosts infromation
    ips=(${1})
    command="#!/usr/bin/env bash\nips=(${ips[@]}); for (( i=0; i<\${#ips[*]}; i++ )); do sed -ri ':a;N;\$!ba;s/[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3} ${DOMAIN}/'\"\${ips[\$i]}\"' ${DOMAIN}/'\"\$((i+1))\"'' ${2}; done"
    tmp_dir_path="$(mktemp -d)"
    echo -en "$command" > "${tmp_dir_path}/script.sh"
    log "Changing ${DOMAIN} IPs to: ${ips[@]}\n"
    ansible -i "${ANSIBLE_INVENTORY_PATH}" 'masters' -b -m script -a "${tmp_dir_path}/script.sh"
    ansible -i "${ANSIBLE_INVENTORY_PATH}" 'masters' -b -m shell -a 'cat '"${HOST_FILE_PATH}"''
    log "Restarting master services\n"
    ansible -i "${ANSIBLE_INVENTORY_PATH}" 'masters' -b -m shell -a 'systemctl restart master-controllers'
}

# run functions
getDomainAlias "${AWS_PROFILE}" "${HOSTED_ZONE_ID}" "${DOMAIN}"
getAliasIp "${domain_alias}"
updateIpsInStaticFiles "${domain_ips}" "${HOST_FILE_PATH}"