Prerequisites to manage apps

A Cisco GMM account with admin privileges
An IOx fog application deployed on Cisco GMM

Stop or start the apps on a gateway

Select Applications > Applications and click an app name.
Click the Instances tab and select a gateway where the app is installed.
Select Stop App or Start App.

Tip: Click Refresh App to restart the app.

Gateway custom fields in IOx applications

The custom fields defined for GMM gateways can be passed down to the IOx apps installed on the gateway. The IOx app consumes these custom fields during its runtime.

Update the package_config.ini when building the IOx application package using the following:
1. If an "application" section already exists in the ini file, append the following line to that section:
  
  need_gmm_tags : true
  
  For example:
  
  Existing:
```
 [application]
 connection_timeout : 120
```
  Updated:
```
 [application]
 connection_timeout : 120
 need_gmm_tags : true
```
2. If the"application" section does not exist, add a new "application" section:
```
 [application]
 need_gmm_tags : true
```
Add the application to GMM and install it on gateways. Once installed, the final configuration that gets pushed to the running IOx app will include the custom fields from GMM.

For example if there is a custom field called "color" in GMM and its value for a gateway is "red", the IOx app running on that gateway will include the following configuration:
```
 [gmm_tags]
 color : red
```
The IOx application will be able to read this configuration along with the other configuration parameters that get pushed to the app.

Change the app settings

Edit the app template settings that are applied to the gateways using app deployment policies.

Change these settings only if you know the impact.

Uninstall apps from a gateway

Edit the app deployment policies that include the app so the policy does not apply to the gateway.

You can also update the custom fields on the gateway so they no longer match the app deployment policy.