Get AWS RDS Enhanced Monitoring statistics from CloudWatch and show something similar to Linux top command

rds-top.sh

#!/bin/bash
# rds-top.sh
#   by <sherwin@daganato.com>, 20190822
#   based on the work of Matheus de Oliveira <matioli.matheus@gmail.com>
#
# Usage:
#   ./rds-top.sh rds-instance
#   ./rds-top.sh --start-time=$(date -v-13d +%s) rds-instance 
#   ./rds-top.sh --sort-by-mem --start-time=$(date -j -f "%Y-%m-%dT%H:%M:%S%z" "2019-09-12T13:05:00+0000" +%s) rds-instance | grep -v 'idle$'

set -e

function usage()
{
    cat << EOF
Usage: $0 [options] rds_instance_id

OPTIONS:
    -s or --start-time=t           Optional: Specify the start time in seconds since the Unix epoch
    -m or --sort-by-mem            Optional: Sorts output by memory. Default is to sort by CPU
EOF
}


if [ $# -eq 0 ]
then
    usage
    exit
fi


for i in "$@"
do
case $i in
    -s=*|--start-time=*)
        START_TIME="${i#*=}"
        shift
        ;;
    -m | --sort-by-mem )
        SORT_BY_MEM=1
        shift
        ;;
    *)
        # unknown option
    ;;
esac
done
INSTANCE_ID="$1"


if [[ "$INSTANCE_ID" == "" ]]
then
    error "You have to supply an instance ID!"
    usage
    exit
fi


# Get resource id
resource_id="$(aws rds describe-db-instances --db-instance-identifier "$INSTANCE_ID" --output json | jq -r '.DBInstances[].DbiResourceId')"
[[ "$resource_id" == "" ]] && exit 1

# Build logs parameters
params=(--log-group-name RDSOSMetrics --log-stream-name "$resource_id" --limit 1 --output json)
if [[ "$START_TIME" =~ ^[[:digit:]]+$ ]];
then
    params+=(--start-time "$((START_TIME * 1000))" --start-from-head)
fi

# Get log events
message_json=$(aws logs get-log-events "${params[@]}" | jq -r '.events[].message')

echo "${message_json}" |
jq -r '"\(.instanceID) - \(.timestamp) - \(.uptime) up, load average: \(.loadAverageMinute.one), \(.loadAverageMinute.five), \(.loadAverageMinute.fifteen)
Tasks: \(.tasks.total) total, \(.tasks.running) running, \(.tasks.sleeping) sleeping, \(.tasks.stopped) stopped, \(.tasks.zombie) zombie
%Cpu(s): \(.cpuUtilization.user) us, \(.cpuUtilization.system) sy, \(.cpuUtilization.nice) ni, \(.cpuUtilization.idle) id, \(.cpuUtilization.wait) wa, \(.cpuUtilization.steal) st
MiB Mem: \(.memory.total / 1024) total, \(.memory.free / 1024) free, \((.memory.total - .memory.free) / 1024) used, \((.memory.cached + .memory.buffers) / 1024) buff/cache
MiB Swap: \(.swap.total / 1024) total, \(.swap.free / 1024) free, \(.swap.cached) cached"'

echo

echo "${message_json}" |
jq -r '.network[] | "Net \(.interface): \(.rx) rx, \(.tx) tx"'

# Mimic `iostat -x`
echo "${message_json}" |
jq -r '.diskIO[] | "Disk \(.device): \(.tps) tps, \(.rrqmPS) rrqm/s, \(.wrqmPS) wrqm/s, \(.writeKbPS) wKB/S, \(.readKbPS) rKB/S, \(.avgReqSz) avgrq-sz, \(.avgQueueLen) avgqu-sz, \(.await) await, \(.util) %util"'

echo

sort_by=".cpuUsedPc"
if [[ $SORT_BY_MEM -eq 1 ]]
then
    sort_by=".memoryUsedPc"
fi

echo "${message_json}" |
jq -r '["PID", "PPID", "VSS", "RSS", "%CPU", "%MEM", "COMMAND"], (.processList | sort_by('"$sort_by"') | reverse[] | [.id, .parentID, .vss, .rss, .cpuUsedPc, .memoryUsedPc, .name]) | @tsv' |
column -t -s $'\t'