#!/bin/bash

echo ""

unset err

if [ "${nodegroup_name}" == "" ]; then
        echo "Environment variable nodegroup_name must be set"
        err=true
fi

if [ "${nodegroup_size}" == "" ]; then
        echo "Environment variable nodegroup_size must be set"
        echo "Optionally, you can set nodegroup_min and nodegroup_max as well"
        err=true
fi

if [ "${CLUSTER_NAME}" == "" ]; then
        echo "Environment variable CLUSTER_NAME must be set"
        err=true
fi

if [ "${CLUSTER_REGION}" == "" ]; then
        echo "Environment variable CLUSTER_REGION must be set"
        err=true
fi 

if [ "${err}" == "" ]; then
        echo ""
        echo "Scaling node group ${nodegroup_name} in cluster ${CLUSTER_NAME} to ${nodegroup_size} ..."
        ng=$(eksctl get nodegroup --cluster ${CLUSTER_NAME} --name ${nodegroup_name} --output json)
        #echo $ng
        ng=$(echo $ng | cut -d { -f 2 | cut -d } -f 1)
        #echo $ng
        ng="[ {${ng}} ]"
        #echo $ng
        asg=$(echo ${ng} | jq -r '.[].AutoScalingGroupName')
        if [ "${asg}" == "" ]; then
                # if asg was not determined from eksctl, try finding it from aws cli
                ng=$(aws eks describe-nodegroup --cluster-name ${CLUSTER_NAME} --nodegroup-name ${nodegroup_name}) 
                asg=$(echo $ng | jq -r '.nodegroup.resources.autoScalingGroups[0].name')
                max=$(echo ${ng} | jq -r '.nodegroup.scalingConfig.maxSize')
        else
                max=$(echo ${ng} | jq '.[].MaxSize')
        fi
        echo "asg=$asg"
        if [ "$nodegroup_min" == "" ]; then
                min=0
        else
                min=$nodegroup_min
        fi
        if [ ! "$nodegroup_max" == "" ]; then
                max=$nodegroup_max
        fi
        if [ $max -lt $nodegroup_size ]; then
                max=$((nodegroup_size+10))
        fi
        echo "min=$min"
        echo "desired=${nodegroup_size}"
        echo "max=$max"
        CMD="aws autoscaling update-auto-scaling-group --auto-scaling-group-name ${asg} --min-size ${min} --max-size ${max} --desired-capacity ${nodegroup_size} --region ${CLUSTER_REGION}"
        echo ${CMD}
        if [ "${DRY_RUN}" == "" ]; then
                ${CMD}
        fi
else
        echo "Please correct any reported errors and try again"
fi