Replace multi-role checks with action plugin

This approach should make it easier to add new checks without having to
write lots of YAML and doing things against Ansible (e.g.
ignore_errors).

A single action plugin determines what checks to run per each host,
including arguments to the check. A check is implemented as a class with
a run method, with the same signature as an action plugin and module,
and is normally backed by a regular Ansible module.

Each check is implemented as a separate Python file. This allows whoever
adds a new check to focus solely in a single Python module, and
potentially an Ansible module within library/ too.

All checks are automatically loaded, and only active checks that are
requested by the playbook get executed.

1 files changed, 24 insertions, 0 deletions

diff --git a/roles/openshift_health_checker/openshift_checks/mixins.py b/roles/openshift_health_checker/openshift_checks/mixins.py
new file mode 100644
index 000000000..4e0415944
--- /dev/null
+++ b/roles/openshift_health_checker/openshift_checks/mixins.py
@@ -0,0 +1,24 @@
+# pylint: disable=missing-docstring
+from openshift_checks import OpenShiftCheckException
+
+
+class NotContainerized(object):
+    """Mixin for checks that are only active when not in containerized mode."""
+
+    @classmethod
+    def is_active(cls, task_vars):
+        return (
+            # This mixin is meant to be used with subclasses of
+            # OpenShiftCheck. Pylint disables this by default on mixins,
+            # though it relies on the class name ending in 'mixin'.
+            # pylint: disable=no-member
+            super(NotContainerized, cls).is_active(task_vars) and
+            not cls.is_containerized(task_vars)
+        )
+
+    @staticmethod
+    def is_containerized(task_vars):
+        try:
+            return task_vars["openshift"]["common"]["is_containerized"]
+        except (KeyError, TypeError):
+            raise OpenShiftCheckException("'openshift.common.is_containerized' is undefined")