k8s/OpenShift Provider: Remove workingDir Attribute

For users to be able to specifiy a custom working dir for their
container nodes this change removes the hard-coded /tmp workingDir
attribute from the container specs.

The user-specified WORKDIR from the respective Dockerfile is then used.

Change-Id: I0e2c0ca5be0af2360f54336340a40fa37ffe1001

nodepool/driver/kubernetes/provider.py

@@ -281,7 +281,6 @@ class KubernetesProvider(Provider, QuotaSupport):
             'imagePullPolicy': label.image_pull,
             'command': ["/bin/sh", "-c"],
             'args': ["while true; do sleep 30; done;"],
-            'workingDir': '/tmp',
             'env': label.env,
         }
 

nodepool/driver/openshift/provider.py

@@ -210,7 +210,6 @@ class OpenshiftProvider(Provider):
             'imagePullPolicy': label.image_pull,
             'command': ["/bin/sh", "-c"],
             'args': ["while true; do sleep 30; done;"],
-            'workingDir': '/tmp',
             'env': label.env,
         }
         if label.cpu or label.memory:

releasenotes/notes/k8s-provider-remove-default-workdir-21df518c822b2914.yaml

@@ -0,0 +1,10 @@
+---
+upgrade:
+  - |
+    The k8s and OpenShift providers do not longer set the workingDir attribute
+    of their container specs to /tmp.
+
+    For increased flexibility for the user, the working dir specified in the
+    container images Dockerfile is used as the default in container nodes.
+    Please note that this might often be the root dir ('/') if not specified
+    otherwise by the respective Dockerfiles WORKDIR directive.