Move initialization of context to thread local object

The context global variable was already thread local, but its
initialization was only being triggered during the initial import of the
package.  Moved all of the setup of the context variable to a __init__
function of a class that inherits from threading.local.  This ensures
that when a thread starts it will run the __init__ function.

This avoids errors like the following:
Traceback (most recent call last):
  File "src/gevent/greenlet.py", line 854, in gevent._gevent_cgreenlet.Greenlet.run
  File "/root/src/es-cp4d-locust/env/lib/python3.6/site-packages/locust/user/users.py", line 161, in run_user
    user.run()
  File "/root/src/es-cp4d-locust/env/lib/python3.6/site-packages/locust/user/users.py", line 128, in run
    self.on_start()
  File "/root/src/es-cp4d-locust/locustfile.py", line 58, in on_start
    CFG['oc']['namespace'])
  File "/root/src/py-es-cp4d/db2_eventstore_cp4d/context.py", line 23, in __init__
    oc.login(username, password)
  File "/root/src/openshift-client-python/packages/openshift/base_verbs.py", line 156, in login
    r.add_action(oc_action(cur_context(), "login", cmd_args=['-u', username, '-p', password, cmd_args]))
  File "/root/src/openshift-client-python/packages/openshift/context.py", line 37, in cur_context
    return context.stack[-1]
  File "src/gevent/local.py", line 408, in gevent._gevent_clocal.local.__getattribute__
AttributeError: 'gevent._gevent_clocal.local' object has no attribute 'stack'

Author: spilchen

packages/openshift/__init__.py

@@ -12,7 +12,7 @@
 from .ansible import ansible
 
 # Single source for module version
-__VERSION__ = '1.0.3'
+__VERSION__ = '1.0.4'
 
 null = None  # Allow scripts to specify null in object definitions
 

packages/openshift/context.py

@@ -9,24 +9,6 @@
 
 from .result import Result
 
-# All threads will have a context which is
-# managed by a stack of Context objects. As
-# a thread establish additional context using
-# 'with' statements, the stack will push/grow. As
-# 'with' blocks end, the stack will pop/shrink.
-context = local()
-
-context.stack = []
-context.default_oc_path = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_OC_PATH", "oc")  # Assume oc is in $PATH by default
-context.default_kubeconfig_path = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_CONFIG_PATH", None)
-context.default_api_server = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_API_SERVER", None)
-context.default_token = None  # Does not support environment variable injection to discourage this insecure practice
-context.default_ca_cert_path = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_CA_CERT_PATH", None)
-context.default_project = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_PROJECT", None)
-context.default_options = {}
-context.default_loglevel = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_OC_LOGLEVEL", None)
-context.default_skip_tls_verify = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_SKIP_TLS_VERIFY", None)
-
 # Provides defaults for ssh_client context instantiations
 DEFAULT_SSH_HOSTNAME = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_SSH_HOSTNAME", None)
 DEFAULT_SSH_USERNAME = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_SSH_USERNAME", None)
@@ -605,9 +587,29 @@ def timeout(seconds):
     return c
 
 
-root_context = Context()
-root_context.set_timeout(MASTER_TIMEOUT)
+class ThreadLocalContext(local):
+    def __init__(self):
+        self.default_oc_path = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_OC_PATH", "oc")  # Assume oc is in $PATH by default
+        self.default_kubeconfig_path = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_CONFIG_PATH", None)
+        self.default_api_server = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_API_SERVER", None)
+        self.default_token = None  # Does not support environment variable injection to discourage this insecure practice
+        self.default_ca_cert_path = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_CA_CERT_PATH", None)
+        self.default_project = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_PROJECT", None)
+        self.default_options = {}
+        self.default_loglevel = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_OC_LOGLEVEL", None)
+        self.default_skip_tls_verify = os.getenv("OPENSHIFT_CLIENT_PYTHON_DEFAULT_SKIP_TLS_VERIFY", None)
+
+        root_context = Context()
+        root_context.set_timeout(MASTER_TIMEOUT)
 
-# Ensure stack always has at least one member to simplify getting last
-# with [-1]
-context.stack = [root_context]
+        # Ensure stack always has at least one member to simplify getting last
+        # with [-1]
+        self.stack = [root_context]
+
+
+# All threads will have a context which is
+# managed by a stack of Context objects. As
+# a thread establish additional context using
+# 'with' statements, the stack will push/grow. As
+# 'with' blocks end, the stack will pop/shrink.
+context = ThreadLocalContext()