automatic Docker login to ECR via AWS configuration data

docker-login-ecr.bash

docker-login-ecr() {
  local ecr_account_profile=${ECR_ACCOUNT_PROFILE:-utility}
  local ecr_region
  local ecr_account_id
  ecr_account_id="$(aws configure get "$ecr_account_profile.role_arn" | awk -F: '{ print $5 }')"
  if [[ -z "$ecr_account_id" ]] ; then
    return 1
  fi
  ecr_region=$(aws configure get "$ecr_account_profile.region")
  if [[ -z "$ecr_region" ]] ; then
    return 1
  fi
  aws ecr get-login-password \
    --profile="$ecr_account_profile" \
    --region="$ecr_region" \
    | docker login \
        --username=AWS \
        --password-stdin \
        "${ecr_account_id}.dkr.ecr.${ecr_region}.amazonaws.com"
}