Make the namespace attribute on k8s_object optional.

Only pass the --namespace parameter to kubectl if the namespace attribute
is specified. This will let people specify this in the deployment template
instead.

See #81

README.md

@@ -410,7 +410,8 @@ A rule for interacting with Kubernetes objects.
         <p><code>string, optional</code></p>
         <p>The namespace on the cluster within which the actions are
           performed.</p>
-        <p><b>If this is omitted, it will default to
+        <p><b>If this is omitted, it will default to the value specified
+          in the template or if also unspecified there, to the value
           <code>"default"</code>.</b></p>
       </td>
     </tr>

k8s/apply.sh.tpl

@@ -24,4 +24,4 @@ function guess_runfiles() {
 RUNFILES="${PYTHON_RUNFILES:-$(guess_runfiles)}"
 
 PYTHON_RUNFILES=${RUNFILES} %{resolve_script} | \
-  kubectl --cluster="%{cluster}" --namespace="%{namespace}" apply -f -
+  kubectl --cluster="%{cluster}" %{namespace_arg} apply -f -

k8s/create.sh.tpl

@@ -26,4 +26,4 @@ RUNFILES="${PYTHON_RUNFILES:-$(guess_runfiles)}"
 # TODO(mattmoor): Should we create namespaces that do not exist?
 
 PYTHON_RUNFILES=${RUNFILES} %{resolve_script} | \
-  kubectl --cluster="%{cluster}" --namespace="%{namespace}" create -f -
+  kubectl --cluster="%{cluster}" %{namespace_arg} create -f -

k8s/delete.sh.tpl

@@ -23,5 +23,4 @@ function guess_runfiles() {
 
 RUNFILES="${PYTHON_RUNFILES:-$(guess_runfiles)}"
 
-kubectl --cluster="%{cluster}" --namespace="%{namespace}" delete \
-    -f %{unresolved}
+kubectl --cluster="%{cluster}" %{namespace_arg} delete k8s/...-f %{unresolved}

k8s/describe.sh.tpl

@@ -25,5 +25,5 @@ RUNFILES="${PYTHON_RUNFILES:-$(guess_runfiles)}"
 
 RESOURCE_NAME=$(kubectl create --dry-run -f "%{unresolved}" | cut -d'"' -f 2)
 
-kubectl --cluster="%{cluster}" --namespace="%{namespace}" \
-    describe %{kind} "${RESOURCE_NAME}"
+kubectl --cluster="%{cluster}" %{namespace_arg} describe %{kind} \
+  "${RESOURCE_NAME}"

k8s/object.bzl

@@ -140,9 +140,12 @@ def _common_impl(ctx):
     namespace_arg = "$(cat %s)" % _runfiles(ctx, namespace_file)
     files += [namespace_file]
 
+  if namespace_arg:
+    namespace_arg = "--namespace=\"" +  namespace_arg + "\""
+
   substitutions = {
       "%{cluster}": cluster_arg,
-      "%{namespace}": namespace_arg,
+      "%{namespace_arg}": namespace_arg,
       "%{kind}": ctx.attr.kind,
   }
 

k8s/replace.sh.tpl

@@ -24,4 +24,4 @@ function guess_runfiles() {
 RUNFILES="${PYTHON_RUNFILES:-$(guess_runfiles)}"
 
 PYTHON_RUNFILES=${RUNFILES} %{resolve_script} | \
-  kubectl --cluster="%{cluster}" --namespace="%{namespace}" replace -f -
+  kubectl --cluster="%{cluster}" %{namespace_arg} replace -f -