Switch Terraform version based on .terraform-version or tfstate

switchtf.sh

# Switch to Terraform version for this directory.
# Uses presence of .terraform-version file, or find in .tfstate if possible.
switchtf() {
  if [ -f .terraform-version ]; then
    version=`cat .terraform-version`
    chtf $version
    echo "Switched to Terraform $version."
  else
    version=`grep terraform_version .terraform/terraform.tfstate | sed -E 's/^    "terraform_version": "(.+)",$/\1/'`
    if [ -n version ]; then
      echo "Using Terraform version $version from .terraform/terraform.tfstate"
      chtf $version
    else
      echo "Couldn't detect what Terraform version to use."
    fi
  fi
}