Added GCP Netblock Data Source (hashicorp#1416) (hashicorp#1580)

* Added GCP Netblock Data Source (hashicorp#1416)

* Added docs for google_netblock_ip_ranges (hashicorp#1416)

* Code review changes (hashicorp#1416)

docs/d/datasource_google_netblock_ip_ranges.html.markdown

@@ -0,0 +1,39 @@
+---
+layout: "google"
+page_title: "Google: google_netblock_ip_ranges"
+sidebar_current: "docs-google-datasource-netblock-ip-ranges"
+description: |-
+  Use this data source to get the IP ranges from the sender policy framework (SPF) record of \_cloud-netblocks.googleusercontent.com
+---
+
+# google_netblock_ip_ranges
+
+Use this data source to get the IP ranges from the sender policy framework (SPF) record of \_cloud-netblocks.googleusercontent
+
+https://cloud.google.com/compute/docs/faq#where_can_i_find_product_name_short_ip_ranges
+
+## Example Usage
+
+```tf
+data "google_netblock_ip_ranges" "netblock" {}
+
+output "cidr_blocks" {
+  value = "${data.google_netblock_ip_ranges.netblock.cidr_blocks}"
+}
+
+output "cidr_blocks_ipv4" {
+  value = "${data.google_netblock_ip_ranges.netblock.cidr_blocks_ipv4}"
+}
+
+output "cidr_blocks_ipv6" {
+  value = "${data.google_netblock_ip_ranges.netblock.cidr_blocks_ipv6}"
+}
+```
+
+## Attributes Reference
+
+* `cidr_blocks` - Retrieve list of all CIDR blocks.
+
+* `cidr_blocks_ipv4` - Retrieve list of the IP4 CIDR blocks
+
+* `cidr_blocks_ipv6` - Retrieve list of the IP6 CIDR blocks.

google.erb

@@ -91,6 +91,9 @@
       <li<%= sidebar_current("docs-google-kms-secret") %>>
       <a href="/docs/providers/google/d/google_kms_secret.html">google_kms_secret</a>
       </li>
+      <li<%= sidebar_current("docs-google-datasource-netblock-ip-ranges") %>>
+      <a href="/docs/providers/google/d/datasource_google_netblock_ip_ranges.html">google_netblock_ip_ranges</a>
+      </li>
       <li<%= sidebar_current("docs-google-datasource-organization") %>>
       <a href="/docs/providers/google/d/google_organization.html">google_organization</a>
       </li>