1 files changed, 25 insertions, 19 deletions
diff --git a/roles/openshift_health_checker/openshift_checks/memory_availability.py b/roles/openshift_health_checker/openshift_checks/memory_availability.py
index 28805dc37..765ba072d 100644
--- a/roles/openshift_health_checker/openshift_checks/memory_availability.py
+++ b/roles/openshift_health_checker/openshift_checks/memory_availability.py
@@ -1,5 +1,8 @@
-# pylint: disable=missing-docstring
-from openshift_checks import OpenShiftCheck, get_var
+"""Check that recommended memory is available."""
+from openshift_checks import OpenShiftCheck
+
+MIB = 2**20
+GIB = 2**30
 
 
 class MemoryAvailability(OpenShiftCheck):
@@ -11,33 +14,36 @@ class MemoryAvailability(OpenShiftCheck):
     # Values taken from the official installation documentation:
     # https://docs.openshift.org/latest/install_config/install/prerequisites.html#system-requirements
     recommended_memory_bytes = {
-        "masters": 16 * 10**9,
-        "nodes": 8 * 10**9,
-        "etcd": 20 * 10**9,
+        "masters": 16 * GIB,
+        "nodes": 8 * GIB,
+        "etcd": 8 * GIB,
     }
+    # https://access.redhat.com/solutions/3006511 physical RAM is partly reserved from memtotal
+    memtotal_adjustment = 1 * GIB
 
-    @classmethod
-    def is_active(cls, task_vars):
+    def is_active(self):
         """Skip hosts that do not have recommended memory requirements."""
-        group_names = get_var(task_vars, "group_names", default=[])
-        has_memory_recommendation = bool(set(group_names).intersection(cls.recommended_memory_bytes))
-        return super(MemoryAvailability, cls).is_active(task_vars) and has_memory_recommendation
+        group_names = self.get_var("group_names", default=[])
+        has_memory_recommendation = bool(set(group_names).intersection(self.recommended_memory_bytes))
+        return super(MemoryAvailability, self).is_active() and has_memory_recommendation
 
-    def run(self, tmp, task_vars):
-        group_names = get_var(task_vars, "group_names")
-        total_memory_bytes = get_var(task_vars, "ansible_memtotal_mb") * 10**6
+    def run(self):
+        group_names = self.get_var("group_names")
+        total_memory_bytes = self.get_var("ansible_memtotal_mb") * MIB
 
-        min_memory_bytes = max(self.recommended_memory_bytes.get(name, 0) for name in group_names)
+        recommended_min = max(self.recommended_memory_bytes.get(name, 0) for name in group_names)
+        configured_min = float(self.get_var("openshift_check_min_host_memory_gb", default=0)) * GIB
+        min_memory_bytes = configured_min or recommended_min
 
-        if total_memory_bytes < min_memory_bytes:
+        if total_memory_bytes + self.memtotal_adjustment < min_memory_bytes:
             return {
                 'failed': True,
                 'msg': (
-                    'Available memory ({available:.1f} GB) '
-                    'below recommended value ({recommended:.1f} GB)'
+                    'Available memory ({available:.1f} GiB) is too far '
+                    'below recommended value ({recommended:.1f} GiB)'
                 ).format(
-                    available=float(total_memory_bytes) / 10**9,
-                    recommended=float(min_memory_bytes) / 10**9,
+                    available=float(total_memory_bytes) / GIB,
+                    recommended=float(min_memory_bytes) / GIB,
                 ),
             }