Add cluster backup + restore functionality

Adds cluster backup (JSON dump) and restore functions for use in
disaster recovery.

Further, adds additional confirmation to the initialization (as well as
restore) endpoints to avoid accidental triggering, and also groups the
init, backup, and restore commands in the CLI into a new "task"
subsection.

client-cli/cli_lib/cluster.py

@@ -31,10 +31,55 @@ def initialize(config):
     Initialize the PVC cluster
 
     API endpoint: GET /api/v1/initialize
+    API arguments: yes-i-really-mean-it
+    API schema: {json_data_object}
+    """
+    params = {
+        'yes-i-really-mean-it': 'yes'
+    }
+    response = call_api(config, 'post', '/initialize', params=params)
+
+    if response.status_code == 200:
+        retstatus = True
+    else:
+        retstatus = False
+
+    return retstatus, response.json().get('message', '')
+
+
+def backup(config):
+    """
+    Get a JSON backup of the cluster
+
+    API endpoint: GET /api/v1/backup
     API arguments:
     API schema: {json_data_object}
     """
-    response = call_api(config, 'post', '/initialize')
+    response = call_api(config, 'get', '/backup')
+
+    if response.status_code == 200:
+        return True, response.json()
+    else:
+        return False, response.json().get('message', '')
+
+
+def restore(config, cluster_data):
+    """
+    Restore a JSON backup to the cluster
+
+    API endpoint: POST /api/v1/restore
+    API arguments: yes-i-really-mean-it
+    API schema: {json_data_object}
+    """
+    cluster_data_json = json.dumps(cluster_data)
+
+    params = {
+        'yes-i-really-mean-it': 'yes'
+    }
+    data = {
+        'cluster_data': cluster_data_json
+    }
+    response = call_api(config, 'post', '/restore', params=params, data=data)
 
     if response.status_code == 200:
         retstatus = True