enable setting of node labels #1225

Added update_node function to enable setting labels on nodes.  This
exposes the Update a Node function from the Docker API and should
enable promoting/demoting manager nodes inside a swarm.
Signed-off-by: Nathan Shirlberg <nshirlberg@labattfood.com>

docker/api/swarm.py

@@ -69,6 +69,13 @@ class SwarmApiMixin(object):
 
         return self._result(self._get(url, params=params), True)
 
+    @utils.minimum_version('1.24')
+    def update_node(self, node_id, version, node_spec=None):
+        url = self._url('/nodes/{0}/update?version={1}', node_id, str(version))
+        res = self._post_json(url, data=node_spec)
+        self._raise_for_status(res)
+        return True
+
     @utils.minimum_version('1.24')
     def update_swarm(self, version, swarm_spec=None, rotate_worker_token=False,
                      rotate_manager_token=False):

docs/api.md

@@ -1129,6 +1129,11 @@ Update resource configs of one or more containers.
 
 **Returns** (dict): Dictionary containing a `Warnings` key.
 
+## update_node
+
+Update a node.
+See the [Swarm documentation](swarm.md#clientupdate_node).
+
 ## update_service
 
 Update a service, similar to the `docker service update` command. See the

docs/swarm.md

@@ -232,6 +232,30 @@ List Swarm nodes
 
 **Returns:** A list of dictionaries containing data about each swarm node.
 
+### Client.update_node
+
+Update the Node's configuration
+
+**Params:**
+
+* version (int): The version number of the node object being updated. This
+  is required to avoid conflicting writes.
+* node_spec (dict): Configuration settings to update.  Any values not provided 
+  will be removed.  See the official [Docker API documentation](https://docs.docker.com/engine/reference/api/docker_remote_api_v1.24/#/update-a-node) for more details.
+  Default: `None`.
+
+**Returns:** `True` if the request went through. Raises an `APIError` if it
+  fails.
+
+```python
+node_spec = {'Availability': 'active',
+             'Name': 'node-name',
+             'Role': 'manager',				   
+             'Labels': {'foo': 'bar'}
+            }
+client.update_node(node_id='24ifsmvkjbyhk', version=8, node_spec=node_spec)
+```
+
 ### Client.update_swarm
 
 Update the Swarm's configuration

tests/integration/swarm_test.py

+import copy
 import docker
 import pytest
 
@@ -138,3 +139,26 @@ class SwarmTest(helpers.BaseTestCase):
         node_data = self.client.inspect_node(node['ID'])
         assert node['ID'] == node_data['ID']
         assert node['Version'] == node_data['Version']
+
+    @requires_api_version('1.24')
+    def test_update_node(self):
+        assert self.client.init_swarm('eth0')
+        nodes_list = self.client.nodes()
+        node = nodes_list[0]
+        orig_spec = node['Spec']
+
+        # add a new label
+        new_spec = copy.deepcopy(orig_spec)
+        new_spec['Labels'] = {'new.label': 'new value'}
+        self.client.update_node(node_id=node['ID'],
+                                version=node['Version']['Index'],
+                                node_spec=new_spec)
+        updated_node = self.client.inspect_node(node['ID'])
+        assert new_spec == updated_node['Spec']
+
+        # Revert the changes
+        self.client.update_node(node_id=node['ID'],
+                                version=updated_node['Version']['Index'],
+                                node_spec=orig_spec)
+        reverted_node = self.client.inspect_node(node['ID'])
+        assert orig_spec == reverted_node['Spec']

tests/unit/fake_api.py

@@ -14,6 +14,7 @@ FAKE_FILE_NAME = 'file'
 FAKE_URL = 'myurl'
 FAKE_PATH = '/path'
 FAKE_VOLUME_NAME = 'perfectcherryblossom'
+FAKE_NODE_ID = '24ifsmvkjbyhk'
 
 # Each method is prefixed with HTTP method (get, post...)
 # for clarity and readability
@@ -406,6 +407,10 @@ def post_fake_update_container():
     return 200, {'Warnings': []}
 
 
+def post_fake_update_node():
+    return 200, None
+
+
 # Maps real api url to fake response callback
 prefix = 'http+docker://localunixsocket'
 fake_responses = {
@@ -504,4 +509,8 @@ fake_responses = {
         CURRENT_VERSION, prefix, FAKE_VOLUME_NAME
     ), 'DELETE'):
     fake_remove_volume,
+    ('{1}/{0}/nodes/{2}/update?version=1'.format(
+        CURRENT_VERSION, prefix, FAKE_NODE_ID
+    ), 'POST'):
+    post_fake_update_node,
 }

tests/unit/swarm_test.py

+# -*- coding: utf-8 -*-
+
+import json
+
+from . import fake_api
+from ..base import requires_api_version
+from .api_test import (DockerClientTest, url_prefix, fake_request)
+
+
+class SwarmTest(DockerClientTest):
+    @requires_api_version('1.24')
+    def test_node_update(self):
+        node_spec = {
+            'Availability': 'active',
+            'Name': 'node-name',
+            'Role': 'manager',
+            'Labels': {'foo': 'bar'}
+        }
+
+        self.client.update_node(
+            node_id=fake_api.FAKE_NODE_ID, version=1, node_spec=node_spec
+        )
+        args = fake_request.call_args
+        self.assertEqual(
+            args[0][1], url_prefix + 'nodes/24ifsmvkjbyhk/update?version=1'
+        )
+        self.assertEqual(
+            json.loads(args[1]['data']), node_spec
+        )
+        self.assertEqual(
+            args[1]['headers']['Content-Type'], 'application/json'
+        )