Kubernetes CLI cluster monitoring

k8s_mon.sh

#!/bin/bash
#
# "kubectl top nodes" based -> metric-servers or heapster needed
# possible CSV output w/o line 21 
# 
# output example:
# worker-1: 2 % ; 5 % memory
# worker-2: 10 % ; 86 % memory
# 2019/10/04,17.43.08,CPU & RAM,6%,45%
# 

set -e

KUBECTL=$(which kubectl)
NODES=$($KUBECTL get nodes --no-headers -o custom-columns=NAME:.metadata.name | grep -v master)
MINUTES=60

function mon() {
        local node_count=0
        local total_percent_cpu=0
        local total_percent_mem=0
        local readonly nodes=$@

        for n in $nodes; do
                local requests=$($KUBECTL top node --no-headers $n)
                local percent_cpu=$(echo $requests | awk '{print $3}' | tr "%" " " )
                local percent_mem=$(echo $requests | awk '{print $5}'  | tr "%" " " )
                echo "$n: ${percent_cpu}% ; ${percent_mem}% memory"

                node_count=$((node_count + 1))
                total_percent_cpu=$((total_percent_cpu + percent_cpu))
                total_percent_mem=$((total_percent_mem + percent_mem))
        done

        local readonly avg_percent_cpu=$((total_percent_cpu / node_count))
        local readonly avg_percent_mem=$((total_percent_mem / node_count))

        echo "$(date +%Y/%m/%d,%H.%M.%S),CPU & RAM,${avg_percent_cpu}%,${avg_percent_mem}%"
        sleep 60
}

for i in {1..$MINUTES}
do
   mon $NODES
done