Add cycling deployments and updating config

Add kube config with refactor to kube accessor

Add tests for k8s accessor, some styling changes

config_app/config_util/k8sconfig.py

@@ -0,0 +1,47 @@
+import os
+
+SERVICE_ACCOUNT_TOKEN_PATH = '/var/run/secrets/kubernetes.io/serviceaccount/token'
+
+DEFAULT_QE_NAMESPACE = 'quay-enterprise'
+DEFAULT_QE_CONFIG_SECRET = 'quay-enterprise-config-secret'
+
+# The name of the quay enterprise deployment (not config app) that is used to query & rollout
+DEFAULT_QE_DEPLOYMENT_SELECTOR = 'app'
+
+def get_k8s_namespace():
+  return os.environ.get('QE_K8S_NAMESPACE', DEFAULT_QE_NAMESPACE)
+
+class KubernetesConfig(object):
+  def __init__(self, api_host='', service_account_token=SERVICE_ACCOUNT_TOKEN_PATH,
+               qe_namespace=DEFAULT_QE_NAMESPACE,
+               qe_config_secret=DEFAULT_QE_CONFIG_SECRET,
+               qe_deployment_selector=DEFAULT_QE_DEPLOYMENT_SELECTOR):
+    self.api_host = api_host
+    self.qe_namespace = qe_namespace
+    self.qe_config_secret = qe_config_secret
+    self.qe_deployment_selector = qe_deployment_selector
+    self.service_account_token = service_account_token
+
+  @classmethod
+  def from_env(cls):
+    # Load the service account token from the local store.
+    if not os.path.exists(SERVICE_ACCOUNT_TOKEN_PATH):
+      raise Exception('Cannot load Kubernetes service account token')
+
+    with open(SERVICE_ACCOUNT_TOKEN_PATH, 'r') as f:
+      service_token = f.read()
+
+    api_host=os.environ.get('KUBERNETES_SERVICE_HOST', '')
+    port = os.environ.get('KUBERNETES_SERVICE_PORT')
+    if port:
+      api_host += ':' + port
+
+    qe_namespace = get_k8s_namespace()
+    qe_config_secret = os.environ.get('QE_K8S_CONFIG_SECRET', DEFAULT_QE_CONFIG_SECRET)
+    qe_deployment_selector = os.environ.get('QE_DEPLOYMENT_SELECTOR', DEFAULT_QE_DEPLOYMENT_SELECTOR)
+
+    return cls(api_host=api_host, service_account_token=service_token, qe_namespace=qe_namespace,
+               qe_config_secret=qe_config_secret, qe_deployment_selector=qe_deployment_selector)
+
+
+