Implement cluster maintenance mode

Implements a "maintenance mode" for PVC clusters. For now, the only
thing this mode does is disable node fencing while the state is true.
This allows the administrator to tell PVC that network connectivity,
etc. might be interrupted and to avoid fencing nodes.

Closes #70

client-cli/cli_lib/cluster.py

@@ -42,6 +42,26 @@ def initialize(config):
 
     return retstatus, response.json()['message']
 
+def maintenance_mode(config, state):
+    """
+    Enable or disable PVC cluster maintenance mode
+
+    API endpoint: POST /api/v1/status
+    API arguments: {state}={state}
+    API schema: {json_data_object}
+    """
+    params = {
+        'state': state
+    }
+    response = call_api(config, 'post', '/status', params=params)
+
+    if response.status_code == 200:
+        retstatus = True
+    else:
+        retstatus = False
+
+    return retstatus, response.json()['message']
+
 def get_info(config):
     """
     Get status of the PVC cluster
@@ -67,6 +87,8 @@ def format_info(cluster_information, oformat):
     # Plain formatting, i.e. human-readable
     if cluster_information['health'] == 'Optimal':
         health_colour = ansiprint.green()
+    elif cluster_information['health'] == 'Maintenance':
+        health_colour = ansiprint.blue()
     else:
         health_colour = ansiprint.yellow()