Monitor a connection to a MySQL Endpoint

README.md

Use this script to monitor an RDS instance endpoint, RDS proxy endpoint, Route 53 endpoint during any testing or failover operations.

    $ watch --differences -n 1 -t "./monitor-mysql-connection.sh"

monitor-mysql-connection.sh

#!/usr/bin/env bash

[ -z "${DBA_USER}" ] && echo "ERROR: DBA_USER is not defined" && exit 1
[ -z "${DBA_PASSWD}" ] && echo "ERROR: DBA_PASSWD is not defined" && exit 1
[ -z "${PORT}" ] && echo "ERROR: PORT is not defined" && exit 1
[ -z "${INSTANCE_ENDPOINT}" ] && echo "ERROR: INSTANCE_ENDPOINT is not defined" && exit 1


DOCKERIZE=""
if [[ -n "${USE_DOCKER}" ]]; then
  [[ ! $(type -p docker) ]] &&  echo "ERROR: 'docker' client not installed or in PATH" && exit 1
  # This takes took look to lookup each time
  # OUTPUT=$(docker pull mysql)
  DOCKERIZE="docker run -it --rm mysql"
else
  [[ ! $(type -p mysql) ]] &&  echo "ERROR: 'mysql' client not installed or in PATH" && exit 1
fi

INSTANCE_ID=$(cut -d. -f1 <<< "${INSTANCE_ENDPOINT}")

OUTPUT=$(${DOCKERIZE} mysql -h"${INSTANCE_ENDPOINT}" -u"${DBA_USER}" -p"${DBA_PASSWD}" -P"${PORT}" -AUNs --show-warnings --connect-timeout=1 -e 'SELECT NOW(),VERSION(),@@read_only' 2>/dev/null)
RC="$?"
[[ ${RC} -ne 0 ]] && OUTPUT="ERROR [${RC}] $(date)"
echo "${INSTANCE_ID}"$'\t'"${OUTPUT}"
exit "${RC}"