lower disk requirement on "upgrade" context

roles/openshift_health_checker/openshift_checks/disk_availability.py

@@ -33,6 +33,24 @@ def run(self, tmp, task_vars):
         configured_min = int(get_var(task_vars, "openshift_check_min_host_disk_gb", default=0)) * 10**9
         min_free_bytes = configured_min or recommended_min
 
+        # if an "upgrade" context is set, lower the minimum disk requirement
+        # as this signifies an in-place upgrade - the node might have the
+        # required total disk space, but some of that space may already be
+        # in use by the existing OpenShift deployment.
+        context = get_var(task_vars, "r_openshift_health_checker_playbook_context", default="")
+        if context == "upgrade":
+            upgrade_min_required_diskspace = 5.0 * 10**9
+            if free_bytes < upgrade_min_required_diskspace:
+                return {
+                    'failed': True,
+                    'msg': (
+                        'Available disk space ({:.1f} GB) for the volume containing '
+                        '"/var" is below minimum recommended space for an upgrade ({:.1f} GB).'
+                    ).format(float(free_bytes) / 10**9, float(upgrade_min_required_diskspace) / 10**9)
+                }
+
+            return {}
+
         if free_bytes < min_free_bytes:
             return {
                 'failed': True,

roles/openshift_health_checker/test/disk_availability_test.py

@@ -176,7 +176,62 @@ def test_fails_with_insufficient_disk_space(group_names, configured_min, ansible
 
     assert result['failed']
     for word in 'below recommended'.split() + extra_words:
-        assert word in result['msg']
+        assert word in result.get('msg', '')
+
+
+@pytest.mark.parametrize('group_names,context,ansible_mounts,failed,extra_words', [
+    (
+        ['nodes', 'masters'],
+        "upgrade",
+        [{
+            'mount': '/',
+            # not enough space for a master
+            # even under an "upgrade" context
+            'size_available': 1 * 10**9 + 1,
+            'size_total': 21 * 10**9 + 1,
+        }],
+        True,
+        ["1.0 GB"],
+    ),
+    (
+        ['nodes', 'masters'],
+        "upgrade",
+        [{
+            'mount': '/',
+            # not enough space for a master,
+            # but enough under "upgrade" context
+            'size_available': 10 * 10**9 + 1,
+            'size_total': 21 * 10**9 + 1,
+        }],
+        False,
+        [],
+    ),
+    (
+        ['nodes', 'masters'],
+        "health",
+        [{
+            'mount': '/',
+            # not enough space for a master,
+            # "health" context should not lower requirement
+            'size_available': 20 * 10**9 + 1,
+        }],
+        True,
+        ["20.0 GB", "below minimum"],
+    ),
+])
+def test_min_required_space_decreases_with_upgrade_context(group_names, context, ansible_mounts, failed, extra_words):
+    task_vars = dict(
+        r_openshift_health_checker_playbook_context=context,
+        group_names=group_names,
+        ansible_mounts=ansible_mounts,
+    )
+
+    check = DiskAvailability(execute_module=fake_execute_module)
+    result = check.run(tmp=None, task_vars=task_vars)
+
+    assert result.get("failed", False) == failed
+    for word in extra_words:
+        assert word in result.get('msg', '')
 
 
 def fake_execute_module(*args):