Add Helm delete deployment action (#10)

* add Helm delete deployment action

* fix docs formatting

* rename Helm delete action to Helm undeploy

Author: stplasim

helm-undeploy/action.yml

@@ -0,0 +1,39 @@
+name: "Helm Undeploy"
+description: "Undeploy a Helm deployment from a Kubernetes cluster"
+
+inputs:
+  namespace:
+    description: "The namespace of the Helm release"
+    required: true
+  release-name:
+    description: "The name of the Helm release"
+    required: true
+
+runs:
+  using: "composite"
+  steps:
+    - name: Delete Helm deployment
+      env:
+        HELM_DRIVER: configmaps
+      run: |
+        RELEASE_NAME="${{ inputs.release-name }}"
+        NAMESPACE="${{ inputs.namespace }}"
+
+        echo "Checking Helm release: $RELEASE_NAME in namespace: $NAMESPACE"
+
+        STATUS_OUTPUT=$(helm status "$RELEASE_NAME" --namespace "$NAMESPACE" 2>&1) && STATUS_EXIT=0 || STATUS_EXIT=$?
+
+        if [ $STATUS_EXIT -eq 0 ]; then
+          echo "Release found. Uninstalling..."
+          helm uninstall "$RELEASE_NAME" --namespace "$NAMESPACE"
+        else
+          if echo "$STATUS_OUTPUT" | grep -qi "forbidden\|cannot list\|unauthorized\|permission"; then
+            echo "::error::Permission denied when querying release '$RELEASE_NAME'. Check kubeconfig and RBAC permissions."
+            echo "$STATUS_OUTPUT"
+            exit 1
+          else
+            echo "Release '$RELEASE_NAME' not found, skipping uninstall."
+            echo "$STATUS_OUTPUT"
+          fi
+        fi
+      shell: bash

readme.md

@@ -90,6 +90,28 @@ The following inputs can be used as `step.with` keys:
 | `timeout`            | `5m`             | The timeout for the Helm command                                 |
 | `working-directory`  | `.`              | The working directory where the action commands will operate     |
 
+### Helm Undeploy
+
+Undeploy a Helm deployment from a Kubernetes cluster. Checks if the release exists before attempting uninstall and detects permission errors. Requires Kubernetes to be configured first.
+
+#### Example
+
+```yaml
+  - uses: aboutbits/github-actions-kubernetes/helm-undeploy@v4
+    with:
+      release-name: my-app
+      namespace: my-namespace
+```
+
+#### Inputs
+
+The following inputs can be used as `step.with` keys:
+
+| Name           | Required/Default | Description                    |
+|----------------|------------------|--------------------------------|
+| `namespace`    | required         | The namespace of the Helm release |
+| `release-name` | required         | The name of the Helm release   |
+
 ### Setup S3 Preview
 
 Creates an S3 preview prefix by copying from the main prefix.