Limit compatibility to Helm =>v3.0.0,<4.0.0 (#1039) (#1071)

This is a backport of PR #1039 as merged into main (13791ec).
SUMMARY
Helm v4 is a major version with backward-incompatible changes, including to the flags and output of the Helm CLI and to the SDK. This version is currently not supported in the kubernetes.core. This PR is related to #1038 and is a short-term solution to mark compatibility explicitly
ISSUE TYPE

Bugfix Pull Request
Docs Pull Request

COMPONENT NAME

helm
helm_template
helm_info
helm_repository
helm_pull
helm_registry_auth
helm_plugin
helm_plugin_info

ADDITIONAL INFORMATION
Added `validate_helm_version()`` method to AnsibleHelmModule that enforces version constraint >=3.0.0,<4.0.0.
Fails fast with clear error message: "Helm version must be >=3.0.0,<4.0.0, current version is {version}"
Some modules (i.e. helm_registry_auth) technically is compatible with Helm v4, but validation was added to all helm modules.
Partially coauthored by GitHub Copilot with Claude Sonnet 4 model.
Addresses issue #1038

Reviewed-by: Bianca Henderson <beeankha@gmail.com>
Reviewed-by: Mike Graves <mgraves@redhat.com>

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

@@ -7,3 +7,4 @@
     - "v3.15.4"
     - "v3.16.0"
     - "v3.17.0"
+    - "v4.0.0"

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

@@ -13,45 +13,53 @@
   include_role:
     name: install_helm
 
-- name: "Ensure we honor the environment variables"
-  include_tasks: test_read_envvars.yml
+- name: Main helm tests with Helm v3
+  when: helm_version != "v4.0.0"
+  block:
 
-- name: Deploy charts
-  include_tasks: "tests_chart/{{ test_chart_type }}.yml"
-  loop_control:
-    loop_var: test_chart_type
-  with_items:
-    - from_local_path
-    - from_repository
-    - from_url
+    - name: "Ensure we honor the environment variables"
+      include_tasks: test_read_envvars.yml
+      when: helm_version != "v4.0.0"
 
-- name: test helm upgrade with reuse_values
-  include_tasks: test_helm_reuse_values.yml
+    - name: Deploy charts
+      include_tasks: "tests_chart/{{ test_chart_type }}.yml"
+      loop_control:
+        loop_var: test_chart_type
+      with_items:
+        - from_local_path
+        - from_repository
+        - from_url
 
-- name: test helm upgrade with reset_then_reuse_values
-  include_tasks: test_helm_reset_then_reuse_values.yml
+    - name: test helm upgrade with reuse_values
+      include_tasks: test_helm_reuse_values.yml
 
-- name: test helm dependency update
-  include_tasks: test_up_dep.yml
+    - name: test helm upgrade with reset_then_reuse_values
+      include_tasks: test_helm_reset_then_reuse_values.yml
 
-- name: Test helm uninstall
-  include_tasks: test_helm_uninstall.yml
+    - name: test helm dependency update
+      include_tasks: test_up_dep.yml
 
-- name: Test helm install with chart name containing space
-  include_tasks: test_helm_with_space_into_chart_name.yml
+    - name: Test helm uninstall
+      include_tasks: test_helm_uninstall.yml
 
-# https://github.com/ansible-collections/community.kubernetes/issues/296
-- name: Test Skip CRDS feature in helm chart install
-  include_tasks: test_crds.yml
+    - name: Test helm install with chart name containing space
+      include_tasks: test_helm_with_space_into_chart_name.yml
 
-- name: Test insecure registry flag feature
-  include_tasks: test_helm_insecure.yml
+    # https://github.com/ansible-collections/community.kubernetes/issues/296
+    - name: Test Skip CRDS feature in helm chart install
+      include_tasks: test_crds.yml
 
-- name: Test take ownership flag feature
-  include_tasks: test_helm_take_ownership.yml
+    - name: Test insecure registry flag feature
+      include_tasks: test_helm_insecure.yml
 
-- name: Test helm skip_schema_validation
-  include_tasks: test_skip_schema_validation.yml
+    - name: Test take ownership flag feature
+      include_tasks: test_helm_take_ownership.yml
+
+    - name: Test helm skip_schema_validation
+      include_tasks: test_skip_schema_validation.yml
+
+- name: Test helm version
+  include_tasks: test_helm_version.yml
 
 - name: Clean helm install
   file:

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

@@ -0,0 +1,47 @@
+---
+- name: Test helm reuse_values
+  vars:
+    helm_namespace: "{{ test_namespace[14] }}"
+    chart_release_values:
+      replica:
+        replicaCount: 3
+      master:
+        count: 1
+        kind: Deployment
+    chart_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
+      ignore_errors: true
+      when: helm_version == "v4.0.0"
+
+    - name: Debug install result
+      debug:
+        var: install
+      when: helm_version == "v4.0.0"
+
+    - name: Ensure helm installation was failed for v4.0.0
+      assert:
+        that:
+          - install is failed
+          - "'Helm version must be >=3.0.0,<4.0.0' in install.msg"
+      when: helm_version == "v4.0.0"
+
+  always:
+    - name: Remove helm namespace
+      k8s:
+        api_version: v1
+        kind: Namespace
+        name: "{{ helm_namespace }}"
+        state: absent