Return diff in helm check mode (#290)

Return diff in helm check mode

When the helm module is executed in check mode with the helm diff plugin
installed, it now returns the diff.
SUMMARY
When the helm module is executed in check mode with the helm diff plugin
installed, it now returns the diff.
COMPONENT NAME
helm
ADDITIONAL INFORMATION

Reviewed-by: Abhijeet Kasurde <None>
Reviewed-by: Fabrice <None>
Reviewed-by: Mike Graves <mgraves@redhat.com>
Reviewed-by: None <None>

plugins/modules/helm.py

@@ -537,7 +537,7 @@ def helmdiff_check(
             cmd += " -f=" + values_file
 
     rc, out, err = run_helm(module, cmd)
-    return len(out.strip()) > 0
+    return (len(out.strip()) > 0, out.strip())
 
 
 def default_check(release_status, chart_info, values=None, values_files=None):
@@ -725,7 +725,7 @@ def main():
         else:
 
             if has_plugin(helm_cmd_common, "diff") and not chart_repo_url:
-                would_change = helmdiff_check(
+                (would_change, prepared) = helmdiff_check(
                     module,
                     helm_cmd_common,
                     release_name,
@@ -735,6 +735,8 @@ def main():
                     chart_version,
                     replace,
                 )
+                if would_change and module._diff:
+                    opt_result["diff"] = {"prepared": prepared}
             else:
                 module.warn(
                     "The default idempotency check can fail to report changes in certain cases. "