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

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: GomathiselviS <gomathiselvi@gmail.com>
Reviewed-by: Yuriy Novostavskiy <yuriy@novostavskiy.kyiv.ua>
Reviewed-by: Mike Graves <mgraves@redhat.com>
Reviewed-by: Alina Buzachis
Reviewed-by: Bianca Henderson <beeankha@gmail.com>

plugins/module_utils/helm.py

@@ -202,6 +202,24 @@ class AnsibleHelmModule(object):
             return m.group(1)
         return None
 
+    def validate_helm_version(self):
+        """
+        Validate that Helm version is >=3.0.0 and <4.0.0.
+        Helm 4 is not yet supported.
+        """
+        helm_version = self.get_helm_version()
+        if helm_version is None:
+            self.fail_json(msg="Unable to determine Helm version")
+
+        if (LooseVersion(helm_version) < LooseVersion("3.0.0")) or (
+            LooseVersion(helm_version) >= LooseVersion("4.0.0")
+        ):
+            self.fail_json(
+                msg="Helm version must be >=3.0.0,<4.0.0, current version is {0}".format(
+                    helm_version
+                )
+            )
+
     def get_values(self, release_name, get_all=False):
         """
         Get Values from deployed release

plugins/modules/helm.py

@@ -928,6 +928,9 @@ def main():
     if not IMP_YAML:
         module.fail_json(msg=missing_required_lib("yaml"), exception=IMP_YAML_ERR)
 
+    # Validate Helm version >=3.0.0,<4.0.0
+    module.validate_helm_version()
+
     changed = False
 
     chart_ref = module.params.get("chart_ref")

plugins/modules/helm_info.py

@@ -245,6 +245,9 @@ def main():
     if not IMP_YAML:
         module.fail_json(msg=missing_required_lib("yaml"), exception=IMP_YAML_ERR)
 
+    # Validate Helm version >=3.0.0,<4.0.0
+    module.validate_helm_version()
+
     release_name = module.params.get("release_name")
     release_state = module.params.get("release_state")
     get_all_values = module.params.get("get_all_values")

plugins/modules/helm_plugin.py

@@ -161,6 +161,9 @@ def main():
         mutually_exclusive=mutually_exclusive(),
     )
 
+    # Validate Helm version >=3.0.0,<4.0.0
+    module.validate_helm_version()
+
     state = module.params.get("state")
 
     helm_cmd_common = module.get_helm_binary() + " plugin"

plugins/modules/helm_plugin_info.py

@@ -98,6 +98,9 @@ def main():
         supports_check_mode=True,
     )
 
+    # Validate Helm version >=3.0.0,<4.0.0
+    module.validate_helm_version()
+
     plugin_name = module.params.get("plugin_name")
 
     plugin_list = []

plugins/modules/helm_pull.py

@@ -21,7 +21,7 @@ description:
   - There are options for unpacking the chart after download.
 
 requirements:
-  - "helm >= 3.0 (https://github.com/helm/helm/releases)"
+  - "helm >= 3.0, <4.0.0 (https://github.com/helm/helm/releases)"
 
 options:
   chart_ref:
@@ -220,13 +220,10 @@ def main():
         mutually_exclusive=[("chart_version", "chart_devel")],
     )
 
+    # Validate Helm version >=3.0.0,<4.0.0
+    module.validate_helm_version()
+
     helm_version = module.get_helm_version()
-    if LooseVersion(helm_version) < LooseVersion("3.0.0"):
-        module.fail_json(
-            msg="This module requires helm >= 3.0.0, current version is {0}".format(
-                helm_version
-            )
-        )
 
     helm_pull_opt_versionning = dict(
         skip_tls_certs_check="3.3.0",

plugins/modules/helm_registry_auth.py

@@ -20,7 +20,7 @@ author:
   - Yuriy Novostavskiy (@yurnov)
 
 requirements:
-  - "helm (https://github.com/helm/helm/releases) => 3.8.0"
+  - "helm (https://github.com/helm/helm/releases) >= 3.8.0, <4.0.0"
 
 description:
   -  Helm registry authentication module allows you to login C(helm registry login) and logout C(helm registry logout) from a Helm registry.
@@ -194,6 +194,9 @@ def main():
         supports_check_mode=True,
     )
 
+    # Validate Helm version >=3.0.0,<4.0.0
+    module.validate_helm_version()
+
     changed = False
 
     host = module.params.get("host")

plugins/modules/helm_repository.py

@@ -295,6 +295,9 @@ def main():
     if not IMP_YAML:
         module.fail_json(msg=missing_required_lib("yaml"), exception=IMP_YAML_ERR)
 
+    # Validate Helm version >=3.0.0,<4.0.0
+    module.validate_helm_version()
+
     changed = False
 
     repo_name = module.params.get("repo_name")

plugins/modules/helm_template.py

@@ -347,6 +347,9 @@ def main():
     if not IMP_YAML:
         module.fail_json(msg=missing_required_lib("yaml"), exception=IMP_YAML_ERR)
 
+    # Validate Helm version >=3.0.0,<4.0.0
+    module.validate_helm_version()
+
     helm_cmd = module.get_helm_binary()
 
     if plain_http: