Add support for kubecontext fixture.

docs/writing_tests.rst

@@ -11,30 +11,41 @@ you can access it from wherever the tests are being run.
 Cluster Configuration
 ---------------------
 
-By default, kubetest will look for a config file at ``~/.kube/config`` -- this
-is the same place that ``kubectl`` looks for the cluster config. Generally, if
-you can reach your cluster via. ``kubectl``, you should be able to use it with
-kubetest.
+By default, kubetest will look for a config file at ``~/.kube/config`` and the 
+current context -- this is the same behavior that ``kubectl`` utilizes for the 
+resolving cluster config. Generally, if you can reach your cluster via. 
+``kubectl``, you should be able to use it with kubetest.
 
-If you wish to specify a different config file, you can pass it in via the
-``--kube-config`` flag. See :ref:`command_line_usage` for more details.
+If you wish to specify a different config file and/or context, you can pass it 
+in via the ``--kube-config`` and ``--kube-context`` flags.
+See :ref:`command_line_usage` for more details.
 
 You can also write a ``kubeconfig`` fixture which provides the path to the
-config path.  This may be useful in case your cluster is generated as part
-of the tests.
+config file and/or a ``kubecontext`` fixture which provides the name of the 
+context to be used.  This may be useful in case your cluster is generated as 
+part of the tests or you wish to use specific contexts in different parts of
+the suite.
 
 .. code-block:: python
 
     import pytest
     import subprocess
+    from typing import Optional
 
 
     @pytest.fixture
-    def kubeconfig():
+    def kubeconfig() -> str:
         # Here, Terraform creates a cluster and outputs a kubeconfig
         # at somepath
         subprocess.check_call(['terraform', 'apply'])
         return 'somepath/kubeconfig'
+    
+
+    @pytest.fixture
+    def kubecontext() -> Optional[str]:
+        # Return None to use the current context as set in the kubeconfig
+        # Or return the name of a specific context in the kubeconfig
+        return 'kubetest-cluster'
 
 
      def test_my_terraformed_cluster(kube):

kubetest/plugin.py

@@ -13,6 +13,8 @@
 import pytest
 import urllib3
 
+from typing import Optional
+
 from kubetest import errors, markers
 from kubetest.client import TestClient
 from kubetest.manager import KubetestManager
@@ -423,15 +425,25 @@ def clusterinfo(kubeconfig) -> ClusterInfo:
 
 
 @pytest.fixture
-def kubeconfig(request) -> str:
+def kubeconfig(request) -> Optional[str]:
     """Return the name of the configured kube config file loaded for the tests."""
 
     config_file = request.session.config.getoption('kube_config')
     return config_file
 
 
+@pytest.fixture
+def kubecontext(request) -> Optional[str]:
+    """Return the context in the kubeconfig to use for the tests. 
+    
+    When None, use the current context as set in the kubeconfig.
+    """
+
+    context = request.session.config.getoption('kube_context')
+    return context
+
 @pytest.fixture()
-def kube(kubeconfig, request) -> TestClient:
+def kube(kubeconfig, kubecontext, request) -> TestClient:
     """Return a client for managing a Kubernetes cluster for testing."""
 
     if request.session.config.getoption('in_cluster'):
@@ -441,7 +453,7 @@ def kube(kubeconfig, request) -> TestClient:
         if kubeconfig:
             kubernetes.config.load_kube_config(
                 config_file=os.path.expandvars(os.path.expanduser(kubeconfig)),
-                context=request.session.config.getoption('kube_context'),
+                context=kubecontext,
             )
         else:
             log.error(