docker checks: finish and refactor

Incorporated docker_storage_driver into docker_storage as both need
driver info.
Corrected storage calculation to include VG free space, not just the
current amount in the LV pool. Now makes no assumptions about pool name.
Improved user messaging.
Factored out some methods that can be shared with docker_image_availability.

1 files changed, 39 insertions, 1 deletions

diff --git a/roles/openshift_health_checker/openshift_checks/mixins.py b/roles/openshift_health_checker/openshift_checks/mixins.py
index 20d160eaf..1181784ab 100644
--- a/roles/openshift_health_checker/openshift_checks/mixins.py
+++ b/roles/openshift_health_checker/openshift_checks/mixins.py
@@ -1,4 +1,3 @@
-# pylint: disable=missing-docstring,too-few-public-methods
 """
 Mixin classes meant to be used with subclasses of OpenShiftCheck.
 """
@@ -8,8 +7,47 @@ from openshift_checks import get_var
 
 class NotContainerizedMixin(object):
     """Mixin for checks that are only active when not in containerized mode."""
+    # permanent # pylint: disable=too-few-public-methods
+    # Reason: The mixin is not intended to stand on its own as a class.
 
     @classmethod
     def is_active(cls, task_vars):
+        """Only run on non-containerized hosts."""
         is_containerized = get_var(task_vars, "openshift", "common", "is_containerized")
         return super(NotContainerizedMixin, cls).is_active(task_vars) and not is_containerized
+
+
+class DockerHostMixin(object):
+    """Mixin for checks that are only active on hosts that require Docker."""
+
+    dependencies = []
+
+    @classmethod
+    def is_active(cls, task_vars):
+        """Only run on hosts that depend on Docker."""
+        is_containerized = get_var(task_vars, "openshift", "common", "is_containerized")
+        is_node = "nodes" in get_var(task_vars, "group_names", default=[])
+        return super(DockerHostMixin, cls).is_active(task_vars) and (is_containerized or is_node)
+
+    def ensure_dependencies(self, task_vars):
+        """
+        Ensure that docker-related packages exist, but not on atomic hosts
+        (which would not be able to install but should already have them).
+        Returns: msg, failed, changed
+        """
+        if get_var(task_vars, "openshift", "common", "is_atomic"):
+            return "", False, False
+
+        # NOTE: we would use the "package" module but it's actually an action plugin
+        # and it's not clear how to invoke one of those. This is about the same anyway:
+        pkg_manager = get_var(task_vars, "ansible_pkg_mgr", default="yum")
+        result = self.module_executor(pkg_manager, {"name": self.dependencies, "state": "present"}, task_vars)
+        msg = result.get("msg", "")
+        if result.get("failed"):
+            if "No package matching" in msg:
+                msg = "Ensure that all required dependencies can be installed via `yum`.\n"
+            msg = (
+                "Unable to install required packages on this host:\n"
+                "    {deps}\n{msg}"
+            ).format(deps=',\n    '.join(self.dependencies), msg=msg)
+        return msg, result.get("failed") or result.get("rc", 0) != 0, result.get("changed")