Merge pull request #4153 from lwander/gcp-pubsub-docs-update

provider/google: Added missing pubsub documentation

website/source/docs/providers/google/r/pubsub_subscription.html.markdown

@@ -17,8 +17,15 @@ Creates a subscription in Google's pubsub queueing system.  For more information
 
 ```
 resource "google_pubsub_subscription" "default" {
-	name = "default-subscription"
-	topic = "default-topic"
+    name = "default-subscription"
+    topic = "default-topic"
+    ack_deadline_seconds = 20
+    push_config {
+        endpoint = "https://example.com/push"
+        attributes {
+            x-goog-version = "v1"
+        }
+    }
 }
 ```
 
@@ -28,12 +35,22 @@ The following arguments are supported:
 
 * `name` - (Required) A unique name for the resource, required by pubsub.
     Changing this forces a new resource to be created.
+
 * `topic` - (Required) A topic to bind this subscription to, required by pubsub.
     Changing this forces a new resource to be created.
 
-## Attributes Reference
+* `ack_deadline_seconds` - (Optional) The maximum number of seconds a
+    subscriber has to acknowledge a received message, otherwise the message is
+    redelivered. Changing this forces a new resource to be created.
+
+The optional `push_config` block supports:
 
-The following attributes are exported:
+* `push_endpoint` - (Optional) The URL of the endpoint to which messages should
+    be pushed. Changing this forces a new resource to be created.
 
-* `name` - The name of the resource.
-* `topic` - The topic to bind this resource to.
+* `attributes` - (Optional) Key-value pairs of API supported attributes used
+    to control aspects of the message delivery. Currently, only
+    `x-goog-version` is supported, which controls the format of the data
+    delivery. For more information, read [the API docs
+    here](https://cloud.google.com/pubsub/reference/rest/v1/projects.subscriptions#PushConfig.FIELDS.attributes).
+    Changing this forces a new resource to be created.