Shell scripts to manipulate ECS AutoScaling settings

README.md

Shell scripts to manipulate ECS AutoScaling settings

Requirement

• jq
• aws cli

Usage

Show Auto Scaling policies

ecs-autoscaling show policy

Show Auto Scaling target

ecs-autoscaling show policy

Apply Auto Scaling policy & target

ecs-autoscaling show policy path/to/files

config.json

{
  "cluster": "connected-base-dev",
  "service": "web",
  "min_capacity": 1,
  "max_capacity": 4
}

ecs-autoscaling.sh

#!/bin/bash

set -eu -o pipefail

ProgName=$(basename $0)

sub_help() {
  echo "Usage: $ProgName <subcommand>"
  echo ""
  echo "Subcommands:"
  echo "  show"
  echo "  apply"
  echo ""
  echo "Example:"
  echo "  $ProgName show target"
  echo "  $ProgName show policy"
  echo "  $ProgName apply <path>"
  echo ""
  exit 1
}

sub_show() {
  Type=${1:-""}
  case $Type in
    target)
      aws application-autoscaling describe-scalable-targets --service-namespace ecs
      ;;
    policy)
      aws application-autoscaling describe-scaling-policies --service-namespace ecs
      ;;
    *)
      echo "Usage: $ProgName show {target|policy}"
      echo ""
      ;;
  esac
}

as_policy_name="ecs-service-scaling"

sub_apply() {
  set -x
  path=${1:-""}
  if [ -z "$path"  ]; then
    echo "path is required"
    exit 1
  fi

  cluster=$(jq -r '.cluster' $path/config.json)
  service=$(jq -r '.service' $path/config.json)
  min_capacity=$(jq -r '.min_capacity' $path/config.json)
  max_capacity=$(jq -r '.max_capacity' $path/config.json)

  aws application-autoscaling register-scalable-target \
    --service-namespace ecs \
    --resource-id service/$cluster/$service \
    --scalable-dimension ecs:service:DesiredCount \
    --min-capacity $min_capacity \
    --max-capacity $max_capacity

  aws application-autoscaling put-scaling-policy \
    --service-namespace ecs \
    --resource-id service/$cluster/$service \
    --scalable-dimension ecs:service:DesiredCount \
    --policy-name $as_policy_name \
    --policy-type TargetTrackingScaling \
    --target-tracking-scaling-policy-configuration file://$path/policy.json
}

subcommand=${1:-""}

case $subcommand in
  "" | "-h" | "--help" | "help")
    sub_help
    ;;
  *)
    shift
    sub_${subcommand} $@
    if [ $? = 127 ]; then
      echo "Error: '$subcommand' is not a known subcommand." >&2
      echo "       Run '$ProgName --help' for a list of known subcommands." >&2
      exit 1
    fi
    ;;
esac

policy.json

{
  "TargetValue": 60.0,
  "PredefinedMetricSpecification": {
    "PredefinedMetricType": "ECSServiceAverageCPUUtilization"
  }
}