> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nuon.co/llms.txt
> Use this file to discover all available pages before exploring further.

# 018 - Management Mode

> Runner Management Mode, input updates, and App Variables for storing values across installs.

*Sep 8, 2025*

<div className="badge badge--primary">v0.19.630</div>

## Management Mode

Management mode is a standalone runner process that runs on the install runner
VM and is responsible for monitoring and managing the health of the VM as well
as the runner process itself. Read more about how to enable this for your
installs here: [Runner Management Mode](/guides/runner-management-mode).

## Stack Config Breaking Change

We fixed a bug where the `runner_nested_template_url` is now recognized, where
as before it was ignored.

<Warning>
  This requires a config update for any apps that currently define a
  `runner_nested_template_url` in their `stack.toml`, as older versions of the
  nested template could be invalid or not work.
</Warning>

We recommend using the latest nested template url:

```toml theme={null}
runner_nested_template_url = "https://nuon-artifacts.s3.us-west-2.amazonaws.com/aws-cloudformation-templates/v0.1.6/runner/asg/stack.yaml"
```

## Sensitive Inputs and Install Config Files

When you generate a config, inputs will now be grouped together, reflecting the
input groups you have defined in the app. Sensitive inputs will be excluded, to
avoid saving them in plain text in version control.

```toml theme={null}
name = "my_install"

[aws_account]
  region = "us-east-1"

[[inputs]]
  use_insecure_cookies = "false"

[[inputs]]
  bool_type = "true"
  json_type = "{\"key\": \"value\"}"
  number_type = "10"
```

When syncing install config files, sensitive inputs will be ignored. They can
still be managed manually via the dashboard.

## App Variables

App Variables is a feature that allows you to define values you can use across
all installs of an app. The values are not managed in the app itself, and
therefore do not need to be stored in version control, and are not displayed to
your customer during the install process.

You can create app variables via the CLI.

```sh theme={null}
nuon apps variables create --name=my_var --value="some value"
```

To use an app variable, interpolate them in your app.

```toml actions/demo_action.toml theme={null}
# action

name    = "simple_demonstration"
timeout = "1m"

[[triggers]]
type = "manual"

[[steps]]
name    = "show the value of my_var"
inline_contents = """
#!/usr/bin/env sh

echo $MY_VAR
"""
[steps.env_vars]
MY_VAR="{{.nuon.app.variables.my_var}}"
```

Learn more about App Variables here:
[Concepts - App Variables](/concepts/app-variables).

## Orderable Action Triggers

It is often useful to be able to define an explicit order for actions. We are
introducing a new optional field ,`index`, on action triggers that allows you to
define an order for actions with the same trigger. For example, you can define a
trigger like this in one action:

```toml theme={null}
# post_cert_deploy_action_1.toml
[[triggers]]
type           = "post-component-deploy"
component_name = "certificate"
index          = 1
```

and in another action:

```toml theme={null}
# post_cert_deploy_action_2.toml
[[triggers]]
type           = "post-component-deploy"
component_name = "certificate"
index          = 2
```

This will result in the actions running in the order defined by `index`.

## Bug Fixes

* Nested Runner ASG Cloudformation Stack is now respected and used during
  install stack re/provisions.
* Fixed a bug causing workflow cancellation to intermittently fail.
* Fixed a bug where large plans could cause failures when being checked for noop
  plans.