Undo pending RDS changes

rds-undo.sh

#!/usr/bin/env bash

set -euo pipefail

NAME="$1"

description=$(aws rds describe-db-instances --db-instance-identifier "$NAME")

instance_type=$(echo $description | jq -r '.DBInstances[0] | .DBInstanceClass')
allocated_storage=$(echo $description | jq -r '.DBInstances[0] | .AllocatedStorage')
storage_type=$(echo $description | jq -r '.DBInstances[0] | .StorageType')

pending_changes=$(echo $description | jq -r '.DBInstances[0].PendingModifiedValues')

pending_instance_type=$(echo $pending_changes | jq -r '.DBInstanceClass')
pending_allocated_storage=$(echo $pending_changes | jq -r '.AllocatedStorage')
pending_storage_type=$(echo $pending_changes | jq -r '.StorageType')

if [[ $storage_type == "io1" ]]; then
  storage_iops=$(echo $description | jq -r '.DBInstances[0] | .Iops')
  pending_storage_iops=$(echo $pending_changes | jq -r '.Iops')
fi

pending() {
  echo "Instance: ${NAME} pending - type: ${pending_instance_type:-} storage: ${pending_allocated_storage:-} storage_type: ${pending_storage_type:-} storage_iops: ${pending_storage_iops:-}"
}

current() {
  echo "Instance: ${NAME} current - type: ${instance_type:-} storage: ${allocated_storage:-} storage_type: ${storage_type:-} storage_iops: ${storage_iops:-}"
}

ask() {
  read -p "Continue (y/n)?" choice
  case "$choice" in
  y | Y) ;;
  n | N) echo "Exiting" && exit 0 ;;
  *) echo "Invalid" && exit 1 ;;
  esac
}

current
pending

# Get a comparable string (Super hacky)
if [[ $storage_type == "io1" ]]; then
  pending_total="${pending_instance_type}-${pending_allocated_storage}-${pending_storage_type}-${pending_storage_iops:-}"
  no_change_total="null-null-null-null"
else
  pending_total="${pending_instance_type}-${pending_allocated_storage}-${pending_storage_type}"
  no_change_total="null-null-null"
fi
if [[ $pending_total == $no_change_total ]]; then
  echo "No pending changes for ${NAME}"
  exit 0
fi

if [[ $storage_type == "io1" ]]; then
  echo aws rds modify-db-instance \
    --db-instance-identifier "$NAME" \
    --db-instance-class "$instance_type" \
    --storage-type "$storage_type" \
    --allocated-storage "$allocated_storage" \
    --iops "$storage_iops" \
    --apply-immediately
  ask
  aws rds modify-db-instance \
    --db-instance-identifier "$NAME" \
    --db-instance-class "$instance_type" \
    --storage-type "$storage_type" \
    --allocated-storage "$allocated_storage" \
    --iops "$storage_iops" \
    --apply-immediately
else
  echo aws rds modify-db-instance \
    --db-instance-identifier "$NAME" \
    --db-instance-class "$instance_type" \
    --storage-type "$storage_type" \
    --allocated-storage "$allocated_storage" \
    --apply-immediately
  ask
  aws rds modify-db-instance \
    --db-instance-identifier "$NAME" \
    --db-instance-class "$instance_type" \
    --storage-type "$storage_type" \
    --allocated-storage "$allocated_storage" \
    --apply-immediately
fi
current
pending