Fix docker_image_availability checks

This commit ensures that oreg_url is properly templated
by ansible before being consumed in the logic.

This commit also adds a method to the base health check
class to detect if self._templar is none, and return
the appropriate templated/untemplated version of the
variable.  This is mostly for unit tests.

roles/openshift_health_checker/openshift_checks/__init__.py

@@ -95,6 +95,13 @@ class OpenShiftCheck(object):
         # These are intended to be a sequential record of what the check observed and determined.
         self.logs = []
 
+    def template_var(self, var_to_template):
+        """Return a templated variable if self._templar is not None, else
+           just return the variable as-is"""
+        if self._templar is not None:
+            return self._templar.template(var_to_template)
+        return var_to_template
+
     @abstractproperty
     def name(self):
         """The name of this check, usually derived from the class name."""

roles/openshift_health_checker/openshift_checks/docker_image_availability.py

@@ -64,7 +64,9 @@ class DockerImageAvailability(DockerHostMixin, OpenShiftCheck):
         self.registries["configured"] = regs
 
         # for the oreg_url registry there may be credentials specified
-        components = self.get_var("oreg_url", default="").split('/')
+        oreg_url = self.get_var("oreg_url", default="")
+        oreg_url = self.template_var(oreg_url)
+        components = oreg_url.split('/')
         self.registries["oreg"] = "" if len(components) < 3 else components[0]
 
         # Retrieve and template registry credentials, if provided
@@ -72,9 +74,8 @@ class DockerImageAvailability(DockerHostMixin, OpenShiftCheck):
         oreg_auth_user = self.get_var('oreg_auth_user', default='')
         oreg_auth_password = self.get_var('oreg_auth_password', default='')
         if oreg_auth_user != '' and oreg_auth_password != '':
-            if self._templar is not None:
-                oreg_auth_user = self._templar.template(oreg_auth_user)
-                oreg_auth_password = self._templar.template(oreg_auth_password)
+            oreg_auth_user = self.template_var(oreg_auth_user)
+            oreg_auth_password = self.template_var(oreg_auth_password)
             self.skopeo_command_creds = "--creds={}:{}".format(quote(oreg_auth_user), quote(oreg_auth_password))
 
         # record whether we could reach a registry or not (and remember results)
@@ -153,6 +154,7 @@ class DockerImageAvailability(DockerHostMixin, OpenShiftCheck):
         # template for images that run on top of OpenShift
         image_url = "{}/{}-{}:{}".format(image_info["namespace"], image_info["name"], "${component}", "${version}")
         image_url = self.get_var("oreg_url", default="") or image_url
+        image_url = self.template_var(image_url)
         if 'oo_nodes_to_config' in host_groups:
             for suffix in NODE_IMAGE_SUFFIXES:
                 required.add(image_url.replace("${component}", suffix).replace("${version}", image_tag))