Customize your package installation

You can customize your package configuration that is not exposed through data values by using annotations and ytt overlays.

Customize a package that was manually installed

To customize a package that was installed manually:

Create a secret.yml file with a Secret that contains your ytt overlay. For example:
```
apiVersion: v1
kind: Secret
metadata:
  name: tap-overlay
  namespace: tap-install
stringData:
  custom-package-overlay.yml: |
    CUSTOM-OVERLAY
```
For more information about ytt overlays, see the Carvel documentation.
Apply the Secret to your cluster by running:
```
kubectl apply -f secret.yml
```
Update your PackageInstall to include the ext.packaging.carvel.dev/ytt-paths-from-secret-name.x annotation to reference your new overlay Secret. For example:
```
apiVersion: packaging.carvel.dev/v1alpha1
kind: PackageInstall
metadata:
  name: PACKAGE-NAME
  namespace: tap-install
  annotations:
    ext.packaging.carvel.dev/ytt-paths-from-secret-name: tap-overlay
...
```
Note
You can suffix the extension annotation with .x, where x is a number, to apply multiple overlays. For more information, see the Carvel documentation.

To add an overlay to a package that was installed by using a Tanzu Application Platform profile:

Create a Secret with your ytt overlay. For more information about ytt overlays, see the Carvel documentation.
Update your values file to include a package_overlays field:
```
package_overlays:
- name: PACKAGE-NAME
  secrets:
  - name: SECRET-NAME
```
Where PACKAGE-NAME is the target package for the overlay. For example, tap-gui.

Update Tanzu Application Platform by running:

tanzu package installed update tap -p tap.tanzu.vmware.com -v 1.9.1  --values-file tap-values.yaml -n tap-install

For information about Tanzu Application Platform profiles, see Installing Tanzu Application Platform package and profiles.