Deploying with app manifests

App manifests provide consistency and reproducibility, and can help you automate deploying apps. This topic provides basic procedures and guidance for deploying apps with a manifest file to VMware Tanzu Application Service for VMs (TAS for VMs). Both manifests and command line options allow you to override the default attribute values of cf push. These attributes include the number of app instances, disk space limit, memory limit, and log rate limit.

cf push follows rules of precedence when setting attribute values:

Manifests override most recent values, including defaults and values set by commands such as cf scale.
Command line options override manifests.
The manifest configuration is additive and will not modify any unspecified properties or remove any existing environment variables, routes, or services.

For a full list of attributes you can specify in an app manifest, see App manifest attribute reference.

Deploy an app with a manifest

To deploy an app with a manifest:

Create a manifest.yml file in the root directory of your app. By default, the cf push command uses the manifest.yml file in the app directory. To specify a different location for the manifest, pass its local path to the -f flag when you run cf push.
Add the following content to the file:
```
---
applications:
- name: APP-NAME
```
Where APP-NAME is the name of your app.
Run:
```
cf push
```
If you specify any values with command-line flags, they override the values specified in the manifest. For more information, see Deploy multiple apps with one manifest.

For more information about manifest format and attributes, see App manifest attribute reference.

Deploy multiple apps with one manifest

This section describes how to deploy multiple apps with a minimal manifest. For more information about manifest format and attributes, see App manifest attribute reference.

General rules

Follow these general rules when deploying multiple apps with one manifest:

Use a no-route line in the description of any app that provides background services to another app.
You cannot use any command line options with cf push except for -f and --no-start.
- If your manifest is not named manifest.yml or not in the current working directory, use the -f command line option.
To push a single app rather than all of the apps described in the manifest, provide the app name by running cf push APP-NAME, where APP-NAME is the name of your app.
Each app must be in a subdirectory under the same parent directory.

Procedure

To deploy multiple apps with a manifest:

Create a manifest.yml file in the directory that contains the apps.
Add each app and its directory to the file. TAS for VMs pushes the apps in the order specified in the manifest. If you push multiple apps using a manifest and one fails to deploy, TAS for VMs does not attempt to push apps specified after the app that failed.
```
---
applications:
- name: APP-ONE
  path: ./APP-ONE-DIRECTORY
- name: APP-TWO
  path: ./APP-TWO-DIRECTORY
```
Where:
- APP-ONE is the name of the first app you want TAS for VMs to push.
- APP-ONE-DIRECTORY is the directory containing the first app.
- APP-TWO is the name of the second app you want TAS for VMs to push.
- APP-TWO-DIRECTORY is the directory containing the second app.
From the directory that contains the apps and the manifest, run:
```
cf push
```