1 files changed, 115 insertions, 0 deletions
diff --git a/roles/openshift_health_checker/openshift_checks/disk_availability.py b/roles/openshift_health_checker/openshift_checks/disk_availability.py
new file mode 100644
index 000000000..e93e81efa
--- /dev/null
+++ b/roles/openshift_health_checker/openshift_checks/disk_availability.py
@@ -0,0 +1,115 @@
+"""Check that there is enough disk space in predefined paths."""
+
+import os.path
+import tempfile
+
+from openshift_checks import OpenShiftCheck, OpenShiftCheckException, get_var
+
+
+class DiskAvailability(OpenShiftCheck):
+    """Check that recommended disk space is available before a first-time install."""
+
+    name = "disk_availability"
+    tags = ["preflight"]
+
+    # Values taken from the official installation documentation:
+    # https://docs.openshift.org/latest/install_config/install/prerequisites.html#system-requirements
+    recommended_disk_space_bytes = {
+        '/var': {
+            'masters': 40 * 10**9,
+            'nodes': 15 * 10**9,
+            'etcd': 20 * 10**9,
+        },
+        # Used to copy client binaries into,
+        # see roles/openshift_cli/library/openshift_container_binary_sync.py.
+        '/usr/local/bin': {
+            'masters': 1 * 10**9,
+            'nodes': 1 * 10**9,
+            'etcd': 1 * 10**9,
+        },
+        # Used as temporary storage in several cases.
+        tempfile.gettempdir(): {
+            'masters': 1 * 10**9,
+            'nodes': 1 * 10**9,
+            'etcd': 1 * 10**9,
+        },
+    }
+
+    @classmethod
+    def is_active(cls, task_vars):
+        """Skip hosts that do not have recommended disk space requirements."""
+        group_names = get_var(task_vars, "group_names", default=[])
+        active_groups = set()
+        for recommendation in cls.recommended_disk_space_bytes.values():
+            active_groups.update(recommendation.keys())
+        has_disk_space_recommendation = bool(active_groups.intersection(group_names))
+        return super(DiskAvailability, cls).is_active(task_vars) and has_disk_space_recommendation
+
+    def run(self, tmp, task_vars):
+        group_names = get_var(task_vars, "group_names")
+        ansible_mounts = get_var(task_vars, "ansible_mounts")
+        ansible_mounts = {mount['mount']: mount for mount in ansible_mounts}
+
+        user_config = get_var(task_vars, "openshift_check_min_host_disk_gb", default={})
+        try:
+            # For backwards-compatibility, if openshift_check_min_host_disk_gb
+            # is a number, then it overrides the required config for '/var'.
+            number = float(user_config)
+            user_config = {
+                '/var': {
+                    'masters': number,
+                    'nodes': number,
+                    'etcd': number,
+                },
+            }
+        except TypeError:
+            # If it is not a number, then it should be a nested dict.
+            pass
+
+        # TODO: as suggested in
+        # https://github.com/openshift/openshift-ansible/pull/4436#discussion_r122180021,
+        # maybe we could support checking disk availability in paths that are
+        # not part of the official recommendation but present in the user
+        # configuration.
+        for path, recommendation in self.recommended_disk_space_bytes.items():
+            free_bytes = self.free_bytes(path, ansible_mounts)
+            recommended_bytes = max(recommendation.get(name, 0) for name in group_names)
+
+            config = user_config.get(path, {})
+            # NOTE: the user config is in GB, but we compare bytes, thus the
+            # conversion.
+            config_bytes = max(config.get(name, 0) for name in group_names) * 10**9
+            recommended_bytes = config_bytes or recommended_bytes
+
+            if free_bytes < recommended_bytes:
+                free_gb = float(free_bytes) / 10**9
+                recommended_gb = float(recommended_bytes) / 10**9
+                return {
+                    'failed': True,
+                    'msg': (
+                        'Available disk space in "{}" ({:.1f} GB) '
+                        'is below minimum recommended ({:.1f} GB)'
+                    ).format(path, free_gb, recommended_gb)
+                }
+
+        return {}
+
+    @staticmethod
+    def free_bytes(path, ansible_mounts):
+        """Return the size available in path based on ansible_mounts."""
+        mount_point = path
+        # arbitry value to prevent an infinite loop, in the unlike case that '/'
+        # is not in ansible_mounts.
+        max_depth = 32
+        while mount_point not in ansible_mounts and max_depth > 0:
+            mount_point = os.path.dirname(mount_point)
+            max_depth -= 1
+
+        try:
+            free_bytes = ansible_mounts[mount_point]['size_available']
+        except KeyError:
+            known_mounts = ', '.join('"{}"'.format(mount) for mount in sorted(ansible_mounts)) or 'none'
+            msg = 'Unable to determine disk availability for "{}". Known mount points: {}.'
+            raise OpenShiftCheckException(msg.format(path, known_mounts))
+
+        return free_bytes