Added 'k8s_deployed' fixture

Created a separate fixture for Kubernetes deployment.
Modified existing k8s related fixtures / tests so they
use it now and updated templates with k8s environments.

Also this patch includes few minor changes:

 * removed unused fixture 'deploy_openstack' which
   was a full copy of 'openstack_deployed' fixture;
 * removed unused modules imports;
 * fixed typos and docstrings.

Change-Id: Ic35551f3e52913cede753b92e7d5a81f54570b01
Reviewed-on: https://review.gerrithub.io/365234
Reviewed-by: <vrovachev@mirantis.com>
Reviewed-by: Dennis Dmitriev <dis.xcom@gmail.com>
Tested-by: Tatyanka Leontovich <tleontovich@mirantis.com>
diff --git a/tcp_tests/fixtures/k8s_fixtures.py b/tcp_tests/fixtures/k8s_fixtures.py
new file mode 100644
index 0000000..bec38a5
--- /dev/null
+++ b/tcp_tests/fixtures/k8s_fixtures.py
@@ -0,0 +1,75 @@
+#    Copyright 2017 Mirantis, Inc.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import pytest
+
+from tcp_tests.helpers import ext
+from tcp_tests import logger
+from tcp_tests.managers import k8smanager
+
+LOG = logger.logger
+
+
+@pytest.fixture(scope='function')
+def k8s_actions(config, underlay, salt_deployed):
+    """Fixture that provides various actions for K8S
+
+    :param config: fixture provides oslo.config
+    :param underlay: fixture provides underlay manager
+    :param salt_deployed: fixture provides salt manager
+    :rtype: K8SManager
+
+    For use in tests or fixtures to deploy a custom K8S
+    """
+    return k8smanager.K8SManager(config, underlay, salt_deployed)
+
+
+@pytest.mark.revert_snapshot(ext.SNAPSHOT.k8s_deployed)
+@pytest.fixture(scope='function')
+def k8s_deployed(revert_snapshot, request, config, hardware, underlay,
+                 common_services_deployed, k8s_actions):
+    """Fixture to get or install k8s on environment
+
+    :param revert_snapshot: fixture that reverts snapshot that is specified
+                            in test with @pytest.mark.revert_snapshot(<name>)
+    :param request: fixture provides pytest data
+    :param config: fixture provides oslo.config
+    :param hardware: fixture provides enviromnet manager
+    :param underlay: fixture provides underlay manager
+    :param common_services_deployed: fixture provides CommonServicesManager
+    :param k8s_actions: fixture provides K8SManager instance
+    :rtype: K8SManager
+
+    If config.k8s.k8s_installed is not set, this fixture assumes
+    that the k8s services were not installed, and do the following:
+    - install k8s services
+    - make snapshot with name 'k8s_deployed'
+    - return K8SManager instance
+
+    If config.k8s.k8s_installed was set, this fixture assumes that
+    the k8s services were already installed, and do the following:
+    - return K8SManager instance
+
+    If you want to revert 'k8s_deployed' snapshot, please use mark:
+    @pytest.mark.revert_snapshot("k8s_deployed")
+    """
+
+    # Deploy Kubernetes cluster
+    if not config.k8s.k8s_installed:
+        steps_path = config.k8s_deploy.k8s_steps_path
+        commands = underlay.read_template(steps_path)
+        k8s_actions.install(commands)
+        hardware.create_snapshot(ext.SNAPSHOT.k8s_deployed)
+
+    return k8s_actions
\ No newline at end of file