Add config ability to rollback changes on kube

config_app/config_util/config/TransientDirectoryProvider.py

@@ -1,13 +1,11 @@
 import os
-import base64
 
+from shutil import copytree
 from backports.tempfile import TemporaryDirectory
 
 from config_app.config_util.config.fileprovider import FileConfigProvider
-from config_app.config_util.k8saccessor import KubernetesAccessorSingleton
-from util.config.validator import EXTRA_CA_DIRECTORY, EXTRA_CA_DIRECTORY_PREFIX
-
 
+OLD_CONFIG_SUBDIR = 'old/'
 
 class TransientDirectoryProvider(FileConfigProvider):
   """ Implementation of the config provider that reads and writes the data
@@ -21,6 +19,7 @@ class TransientDirectoryProvider(FileConfigProvider):
     # no uploaded config should ever affect subsequent config modifications/creations
     temp_dir = TemporaryDirectory()
     self.temp_dir = temp_dir
+    self.old_config_dir = None
     super(TransientDirectoryProvider, self).__init__(temp_dir.name, yaml_filename, py_filename)
 
   @property
@@ -38,29 +37,26 @@ class TransientDirectoryProvider(FileConfigProvider):
     self.temp_dir = temp_dir
     self.yaml_path = os.path.join(temp_dir.name, self.yaml_filename)
 
+  def create_copy_of_config_dir(self):
+    """
+    Create a directory to store loaded/populated configuration (for rollback if necessary)
+    """
+    if self.old_config_dir is not None:
+      self.old_config_dir.cleanup()
+
+    temp_dir = TemporaryDirectory()
+    self.old_config_dir = temp_dir
+
+    # Python 2.7's shutil.copy() doesn't allow for copying to existing directories,
+    # so when copying/reading to the old saved config, we have to talk to a subdirectory,
+    # and use the shutil.copytree() function
+    copytree(self.config_volume, os.path.join(temp_dir.name, OLD_CONFIG_SUBDIR))
+
   def get_config_dir_path(self):
     return self.config_volume
 
-  def save_configuration_to_kubernetes(self):
-    data = {}
+  def get_old_config_dir(self):
+    if self.old_config_dir is None:
+      raise Exception('Cannot return a configuration that  was no old configuration')
 
-    # Kubernetes secrets don't have sub-directories, so for the extra_ca_certs dir
-    # we have to put the extra certs in with a prefix, and then one of our init scripts
-    # (02_get_kube_certs.sh) will expand the prefixed certs into the equivalent directory
-    # so that they'll be installed correctly on startup by the certs_install script
-    certs_dir = os.path.join(self.config_volume, EXTRA_CA_DIRECTORY)
-    if os.path.exists(certs_dir):
-      for extra_cert in os.listdir(certs_dir):
-        with open(os.path.join(certs_dir, extra_cert)) as f:
-          data[EXTRA_CA_DIRECTORY_PREFIX + extra_cert] = base64.b64encode(f.read())
-
-
-    for name in os.listdir(self.config_volume):
-      file_path = os.path.join(self.config_volume, name)
-      if not os.path.isdir(file_path):
-        with open(file_path) as f:
-          data[name] = base64.b64encode(f.read())
-
-    KubernetesAccessorSingleton.get_instance().replace_qe_secret(data)
-
-    return 200
+    return os.path.join(self.old_config_dir.name, OLD_CONFIG_SUBDIR)

config_app/config_util/config/__init__.py

@@ -1,6 +1,10 @@
+import base64
+import os
+
 from config_app.config_util.config.fileprovider import FileConfigProvider
 from config_app.config_util.config.testprovider import TestConfigProvider
 from config_app.config_util.config.TransientDirectoryProvider import TransientDirectoryProvider
+from util.config.validator import EXTRA_CA_DIRECTORY, EXTRA_CA_DIRECTORY_PREFIX
 
 
 def get_config_provider(config_volume, yaml_filename, py_filename, testing=False):
@@ -10,3 +14,26 @@ def get_config_provider(config_volume, yaml_filename, py_filename, testing=False
     return TestConfigProvider()
 
   return TransientDirectoryProvider(config_volume, yaml_filename, py_filename)
+
+
+def get_config_as_kube_secret(config_path):
+  data = {}
+
+  # Kubernetes secrets don't have sub-directories, so for the extra_ca_certs dir
+  # we have to put the extra certs in with a prefix, and then one of our init scripts
+  # (02_get_kube_certs.sh) will expand the prefixed certs into the equivalent directory
+  # so that they'll be installed correctly on startup by the certs_install script
+  certs_dir = os.path.join(config_path,  EXTRA_CA_DIRECTORY)
+  if os.path.exists(certs_dir):
+    for extra_cert in os.listdir(certs_dir):
+      with open(os.path.join(certs_dir, extra_cert)) as f:
+        data[EXTRA_CA_DIRECTORY_PREFIX + extra_cert] = base64.b64encode(f.read())
+
+
+  for name in os.listdir(config_path):
+    file_path = os.path.join(config_path, name)
+    if not os.path.isdir(file_path):
+      with open(file_path) as f:
+        data[name] = base64.b64encode(f.read())
+
+  return data

config_app/config_util/k8saccessor.py

@@ -21,6 +21,9 @@ QE_CONTAINER_NAME = 'quay-enterprise-app'
 # message is any string describing the state.
 DeploymentRolloutStatus = namedtuple('DeploymentRolloutStatus', ['status', 'message'])
 
+class K8sApiException(Exception):
+  pass
+
 
 def _deployment_rollout_status_message(deployment, deployment_name):
   """
@@ -225,11 +228,24 @@ class KubernetesAccessorSingleton(object):
         }
       }, api_prefix='apis/extensions/v1beta1', content_type='application/strategic-merge-patch+json'))
 
-  def _assert_success(self, response):
-    if response.status_code != 200:
+  def rollback_deployment(self, deployment_name):
+    deployment_rollback_url = 'namespaces/%s/deployments/%s/rollback' % (
+      self.kube_config.qe_namespace, deployment_name
+    )
+
+    self._assert_success(self._execute_k8s_api('POST', deployment_rollback_url, {
+      'name': deployment_name,
+      'rollbackTo': {
+        # revision=0 makes the deployment rollout to the previous revision
+        'revision': 0
+      }
+    }, api_prefix='apis/extensions/v1beta1'), 201)
+
+  def _assert_success(self, response, expected_code=200):
+    if response.status_code != expected_code:
       logger.error('Kubernetes API call failed with response: %s => %s', response.status_code,
                    response.text)
-      raise Exception('Kubernetes API call failed: %s' % response.text)
+      raise K8sApiException('Kubernetes API call failed: %s' % response.text)
 
   def _update_secret_file(self, relative_file_path, value=None):
     if '/' in relative_file_path: