add reset_then_reuse_values support to helm module (#802)

SUMMARY
Starting with version 3.14.0, Helm supports --reset-then-reuse-values. As discussed on the original PR. This greatly improves on --reuse-values as it allows to avoid templates errors when new features are added to an upgraded chart.
Closes #803
ISSUE TYPE

Feature Pull Request

COMPONENT NAME
helm
ADDITIONAL INFORMATION
This PR is greatly 'inspired' by #575 and because I wasn't sure how I could provide additional tests for it, I actually copied those build previously for --reuse-values (as it is an improvement on this feature.

Reviewed-by: Bikouo Aubin
Reviewed-by: Yuriy Novostavskiy
Reviewed-by: b0z02003
Reviewed-by: Bianca Henderson <beeankha@gmail.com>

changelogs/fragments/800-helm-add-reset_then_reuse_values-support.yml

@@ -0,0 +1,3 @@
+---
+minor_changes:
+  - helm - add reset_then_reuse_values support to helm module (https://github.com/ansible-collections/kubernetes.core/issues/803).

docs/kubernetes.core.helm_module.rst

@@ -435,6 +435,28 @@ Parameters
                         <div>mutually exclusive with with <code>history_max</code>.</div>
                 </td>
             </tr>
+            <tr>
+                <td colspan="2">
+                    <div class="ansibleOptionAnchor" id="parameter-"></div>
+                    <b>reset_then_reuse_values</b>
+                    <a class="ansibleOptionLink" href="#parameter-" title="Permalink to this option"></a>
+                    <div style="font-size: small">
+                        <span style="color: purple">boolean</span>
+                    </div>
+                    <div style="font-style: italic; font-size: small; color: darkgreen">added in 6.0.0</div>
+                </td>
+                <td>
+                        <ul style="margin: 0; padding: 0"><b>Choices:</b>
+                                    <li><div style="color: blue"><b>no</b>&nbsp;&larr;</div></li>
+                                    <li>yes</li>
+                        </ul>
+                </td>
+                <td>
+                        <div>When upgrading package, reset the values to the ones built into the chart, apply the last release&#x27;s values and merge in any overrides from parameters O(release_values), O(values_files) or O(set_values).</div>
+                        <div>If O(reset_values) or O(reuse_values) is set to V(True), this is ignored.</div>
+                        <div>This feature requires helm diff &gt;= 3.9.12.</div>
+                </td>
+            </tr>
             <tr>
                 <td colspan="2">
                     <div class="ansibleOptionAnchor" id="parameter-"></div>

plugins/modules/helm.py

@@ -145,6 +145,16 @@ options:
     required: false
     default: True
     version_added: 3.0.0
+  reset_then_reuse_values:
+    description:
+      - When upgrading package, reset the values to the ones built into the chart, apply the last release's values and merge in any overrides from
+        parameters O(release_values), O(values_files) or O(set_values).
+      - If O(reset_values) or O(reuse_values) is set to V(True), this is ignored.
+      - This feature requires helm diff >= 3.9.12.
+    type: bool
+    required: false
+    default: False
+    version_added: 6.0.0
 
 #Helm options
   disable_hook:
@@ -509,6 +519,7 @@ def deploy(
     set_value_args=None,
     reuse_values=None,
     reset_values=True,
+    reset_then_reuse_values=False,
 ):
     """
     Install/upgrade/rollback release chart
@@ -526,6 +537,17 @@ def deploy(
     if reuse_values is not None:
         deploy_command += " --reuse-values=" + str(reuse_values)
 
+    if reset_then_reuse_values:
+        helm_version = module.get_helm_version()
+        if LooseVersion(helm_version) < LooseVersion("3.14.0"):
+            module.fail_json(
+                msg="reset_then_reuse_values requires helm >= 3.14.0, current version is {0}".format(
+                    helm_version
+                )
+            )
+        else:
+            deploy_command += " --reset-then-reuse-values"
+
     if wait:
         deploy_command += " --wait"
         if wait_timeout is not None:
@@ -642,6 +664,7 @@ def helmdiff_check(
     set_value_args=None,
     reuse_values=None,
     reset_values=True,
+    reset_then_reuse_values=False,
 ):
     """
     Use helm diff to determine if a release would change by upgrading a chart.
@@ -676,6 +699,24 @@ def helmdiff_check(
     if reuse_values:
         cmd += " --reuse-values"
 
+    if reset_then_reuse_values:
+        helm_diff_version = get_plugin_version("diff")
+        helm_version = module.get_helm_version()
+        fail_msg = ""
+        if LooseVersion(helm_diff_version) < LooseVersion("3.9.12"):
+            fail_msg = "reset_then_reuse_values requires helm diff >= 3.9.12, current version is {0}\n".format(
+                helm_diff_version
+            )
+        if LooseVersion(helm_version) < LooseVersion("3.14.0"):
+            fail_msg += "reset_then_reuse_values requires helm >= 3.14.0, current version is {0}\n".format(
+                helm_version
+            )
+
+        if fail_msg:
+            module.fail_json(msg=fail_msg)
+        else:
+            cmd += " --reset-then-reuse-values"
+
     rc, out, err = module.run_helm_command(cmd)
     return (len(out.strip()) > 0, out.strip())
 
@@ -735,6 +776,7 @@ def argument_spec():
             set_values=dict(type="list", elements="dict"),
             reuse_values=dict(type="bool"),
             reset_values=dict(type="bool", default=True),
+            reset_then_reuse_values=dict(type="bool", default=False),
         )
     )
     return arg_spec
@@ -787,6 +829,7 @@ def main():
     set_values = module.params.get("set_values")
     reuse_values = module.params.get("reuse_values")
     reset_values = module.params.get("reset_values")
+    reset_then_reuse_values = module.params.get("reset_then_reuse_values")
 
     if update_repo_cache:
         run_repo_update(module)
@@ -883,6 +926,7 @@ def main():
                 set_value_args=set_value_args,
                 reuse_values=reuse_values,
                 reset_values=reset_values,
+                reset_then_reuse_values=reset_then_reuse_values,
             )
             changed = True
 
@@ -908,6 +952,7 @@ def main():
                     set_value_args,
                     reuse_values=reuse_values,
                     reset_values=reset_values,
+                    reset_then_reuse_values=reset_then_reuse_values,
                 )
                 if would_change and module._diff:
                     opt_result["diff"] = {"prepared": prepared}
@@ -943,6 +988,7 @@ def main():
                     set_value_args=set_value_args,
                     reuse_values=reuse_values,
                     reset_values=reset_values,
+                    reset_then_reuse_values=reset_then_reuse_values,
                 )
                 changed = True
 

tests/integration/targets/helm/defaults/main.yml

@@ -26,3 +26,4 @@ test_namespace:
   - "helm-from-url"
   - "helm-reuse-values"
   - "helm-chart-with-space-into-name"
+  - "helm-reset-then-reuse-values"

tests/integration/targets/helm/tasks/main.yml

@@ -4,4 +4,4 @@
   loop_control:
     loop_var: helm_version
   with_items:
-    - "v3.8.0"
+    - "v3.16.0"

tests/integration/targets/helm/tasks/run_test.yml

@@ -28,6 +28,9 @@
 - name: test helm upgrade with reuse_values
   include_tasks: test_helm_reuse_values.yml
 
+- name: test helm upgrade with reset_then_reuse_values
+  include_tasks: test_helm_reset_then_reuse_values.yml
+
 - name: test helm dependency update
   include_tasks: test_up_dep.yml
 

tests/integration/targets/helm/tasks/test_helm_reset_then_reuse_values.yml

@@ -0,0 +1,75 @@
+---
+- name: Test helm reset_then_reuse_values
+  vars:
+    helm_namespace: "{{ test_namespace[11] }}"
+    chart_release_values:
+      replica:
+        replicaCount: 3
+      master:
+        count: 1
+        kind: Deployment
+    chart_reset_then_reuse_values:
+      replica:
+        replicaCount: 1
+      master:
+        count: 3
+  block:
+    - name: Initial chart installation
+      helm:
+        binary_path: "{{ helm_binary }}"
+        chart_ref: oci://registry-1.docker.io/bitnamicharts/redis
+        release_name: test-redis
+        release_namespace: "{{ helm_namespace }}"
+        create_namespace: true
+        release_values: "{{ chart_release_values }}"
+      register: install
+
+    - name: Get value set as string
+      helm_info:
+        binary_path: "{{ helm_binary }}"
+        release_name: test-redis
+        release_namespace: "{{ helm_namespace }}"
+      register: release_value
+
+    - name: Validate that chart values are as expected
+      assert:
+        that:
+          - install is changed
+          - '"--reset-then-reuse-values" not in install.command'
+          - release_value["status"]["values"] == chart_release_values
+
+    - name: Upgrade chart using reset_then_reuse_values=true
+      helm:
+        binary_path: "{{ helm_binary }}"
+        chart_ref: oci://registry-1.docker.io/bitnamicharts/redis
+        release_name: test-redis
+        release_namespace: "{{ helm_namespace }}"
+        reuse_values: false
+        reset_values: false
+        reset_then_reuse_values: true
+        release_values: "{{ chart_reset_then_reuse_values }}"
+      register: upgrade
+
+    - name: Get value set as string
+      helm_info:
+        binary_path: "{{ helm_binary }}"
+        release_name: test-redis
+        release_namespace: "{{ helm_namespace }}"
+      register: release_value
+
+    - name: Validate that chart values are as expected
+      assert:
+        that:
+          - upgrade is changed
+          - '"--reset-then-reuse-values" in upgrade.command'
+          - '"--reuse-values " not in upgrade.command'
+          - '"--reset-values" not in upgrade.command'
+          - release_value["status"]["values"] == chart_release_values | combine(chart_reset_then_reuse_values, recursive=true)
+
+  always:
+    - name: Remove helm namespace
+      k8s:
+        api_version: v1
+        kind: Namespace
+        name: "{{ helm_namespace }}"
+        state: absent

tests/integration/targets/helm_diff/tasks/main.yml

@@ -10,7 +10,7 @@
         binary_path: "{{ helm_binary }}"
         state: present
         plugin_path: https://github.com/databus23/helm-diff
-        plugin_version: 3.4.0
+        plugin_version: 3.9.13
 
     - name: Copy test chart
       copy:
@@ -324,3 +324,5 @@
       ignore_errors: true
 
 - include_tasks: reuse_values.yml
+
+- include_tasks: reset_then_reuse_values.yml

tests/integration/targets/helm_diff/tasks/reset_then_reuse_values.yml

@@ -0,0 +1,189 @@
+---
+- name: Create temporary directory for helm chart
+  tempfile:
+    suffix: .helm
+    state: directory
+  register: helm_dir
+
+- name: Test helm diff functionality
+  vars:
+    test_chart_path: "{{ helm_dir.path }}/test-chart-reuse-values"
+    test_release_name: "myrelease"
+
+  block:
+    - name: Install helm diff
+      kubernetes.core.helm_plugin:
+        binary_path: "{{ helm_binary }}"
+        state: present
+        plugin_path: https://github.com/databus23/helm-diff
+        plugin_version: 3.9.14
+
+    - name: Copy test chart
+      ansible.builtin.copy:
+        src: "test-chart-reuse-values"
+        dest: "{{ helm_dir.path }}"
+
+    - name: Delete existing namespace
+      kubernetes.core.k8s:
+        state: absent
+        wait: true
+        kind: Namespace
+        name: "{{ helm_namespace }}"
+      ignore_errors: true
+
+    - name: Create helm release
+      kubernetes.core.helm:
+        state: present
+        binary_path: "{{ helm_binary }}"
+        chart_ref: "{{ test_chart_path }}"
+        release_name: "{{ test_release_name }}"
+        release_namespace: "{{ helm_namespace }}"
+        create_namespace: true
+        release_values:
+          ansible_version: devel
+          phase: ci
+        wait: true
+
+    - name: Upgrade helm release (reset_values=false and reuse_values=false and reset_then_reuse_values=true)
+      kubernetes.core.helm:
+        binary_path: "{{ helm_binary }}"
+        chart_ref: "{{ test_chart_path }}"
+        reset_values: false
+        reuse_values: false
+        reset_then_reuse_values: true
+        release_name: "{{ test_release_name }}"
+        release_namespace: "{{ helm_namespace }}"
+        values:
+          ansible_version: devel
+      register: helm_upgrade
+
+    - name: Ensure task did not reported change
+      assert:
+        that:
+          - helm_upgrade is not changed
+
+    - name: Upgrade helm release (reset_then_reuse_values=true with default value for reset_values and reuse_values=false)
+      kubernetes.core.helm:
+        binary_path: "{{ helm_binary }}"
+        chart_ref: "{{ test_chart_path }}"
+        reuse_values: false
+        reset_then_reuse_values: true
+        release_name: "{{ test_release_name }}"
+        release_namespace: "{{ helm_namespace }}"
+        values:
+          ansible_version: devel
+      register: helm_upgrade
+
+    - name: Ensure task reported change
+      assert:
+        that:
+          - helm_upgrade is changed
+
+    # Delete helm and helm diff to install older version
+    - name: Uninstall helm diff
+      helm_plugin:
+        binary_path: "{{ helm_binary }}"
+        state: absent
+        plugin_name: diff
+      ignore_errors: true
+
+    - name: Delete Helm folders
+      file:
+        path: /tmp/helm/
+        state: absent
+
+    - name: Init Helm folders
+      file:
+        path: /tmp/helm
+        state: directory
+
+    - name: Set Helm old version
+      set_fact:
+        helm_archive_name: "helm-v3.8.0-linux-amd64.tar.gz"
+        helm_diff_old_version: "3.8.0"
+
+    - name: Unarchive Helm binary
+      unarchive:
+        src: "https://get.helm.sh/{{ helm_archive_name | default(helm_default_archive_name) }}"
+        dest: /tmp/helm/
+        remote_src: yes
+      retries: 10
+      delay: 5
+      register: result
+      until: result is not failed
+
+    - name: Upgrade helm release (with reset_then_reuse_values=true)
+      kubernetes.core.helm:
+        binary_path: "{{ helm_binary }}"
+        chart_ref: "{{ test_chart_path }}"
+        reuse_values: false
+        reset_then_reuse_values: true
+        release_name: "{{ test_release_name }}"
+        release_namespace: "{{ helm_namespace }}"
+        values:
+          ansible_version: test
+      register: helm_upgrade
+      ignore_errors: true
+
+    - name: Debug
+      debug:
+        var: helm_upgrade
+
+    - name: Ensure warning for Helm version
+      assert:
+        that:
+          - helm_upgrade is failed
+          - '"reset_then_reuse_values requires helm >= 3.14.0, current version is" in helm_upgrade.msg'
+
+    - name: Install helm diff
+      helm_plugin:
+        binary_path: "{{ helm_binary }}"
+        state: present
+        plugin_path: https://github.com/databus23/helm-diff
+        plugin_version: "{{ helm_diff_old_version }}"
+
+    - name: Upgrade helm release (with reset_then_reuse_values=true)
+      kubernetes.core.helm:
+        binary_path: "{{ helm_binary }}"
+        chart_ref: "{{ test_chart_path }}"
+        reuse_values: false
+        reset_then_reuse_values: true
+        release_name: "{{ test_release_name }}"
+        release_namespace: "{{ helm_namespace }}"
+        values:
+          ansible_version: devel
+      register: helm_upgrade
+      ignore_errors: true
+
+    - name: Debug
+      debug:
+        var: helm_upgrade
+
+    - name: Ensure warning for Helm Diff version
+      assert:
+        that:
+          - helm_upgrade is failed
+          - '"reset_then_reuse_values requires helm diff >= 3.9.12, current version is" in helm_upgrade.msg'
+
+  always:
+    - name: Remove temporary directory
+      file:
+        path: "{{ helm_dir.path }}"
+        state: absent
+      ignore_errors: true
+
+    - name: Uninstall helm diff
+      kubernetes.core.helm_plugin:
+        binary_path: "{{ helm_binary }}"
+        state: absent
+        plugin_name: diff
+      ignore_errors: true
+
+    - name: Remove helm namespace
+      kubernetes.core.k8s:
+        api_version: v1
+        kind: Namespace
+        name: "{{ helm_namespace }}"
+        state: absent
+        wait: true
+      ignore_errors: true

tests/integration/targets/helm_diff/tasks/reuse_values.yml

@@ -90,4 +90,5 @@
         kind: Namespace
         name: "{{ helm_namespace }}"
         state: absent
+        wait: true
       ignore_errors: true

tests/integration/targets/install_helm/defaults/main.yml

@@ -1,4 +1,4 @@
 ---
-helm_version: v3.8.0
+helm_version: v3.16.4
 helm_install_path: /tmp/helm
 helm_default_archive_name: "helm-{{ helm_version }}-{{ ansible_system | lower }}-amd64.tar.gz"