[DOCS-12667] Add log collection setup information

content/en/getting_started/integrations/google_cloud.md

@@ -372,11 +372,108 @@
 
 Forwarding logs from your Google Cloud environment enables near real-time monitoring of the resources and activities taking place in your organization or folder. You can set up [log monitors][37] to be notified of issues, use [Cloud SIEM][38] to detect threats, or leverage [Watchdog][39] to identify unknown issues or anomalous behavior.
 
-Use the [Datadog Dataflow template][14] to batch and compresses your log events before forwarding them to Datadog through [Google Cloud Dataflow][15]. This is the most network-efficient way to forward your logs. To specify which logs are forwarded, configure the [Google Cloud Logging sink][40] with any inclusion or exclusion queries using Google Cloud's [Logging query language][56].
+Logs are forwarded by [Google Cloud Dataflow][15] using the [Datadog Dataflow template][14]. This approach offers batching and compression of your log events before forwarding them to Datadog, which is the most network-efficient way to forward your logs. You can specify which logs are forwarded with inclusion and exclusion filters.
 
-You can use the [terraform-gcp-datadog-integration][64] module to manage this infrastructure through Terraform, or follow [the instructions listed here][16] to set up Log Collection. You can also use the [Stream logs from Google Cloud to Datadog][9] guide in the Google Cloud architecture center, for a more detailed explanation of the steps and architecture involved in log forwarding. For a deep dive into the benefits of the Pub/Sub to Datadog template, read [Stream your Google Cloud logs to Datadog with Dataflow][17] in the Datadog blog.
+### Setup
 
-<div class="alert alert-danger">The <b>Dataflow API</b> must be enabled to use Google Cloud Dataflow. See <a href="https://cloud.google.com/apis/docs/getting-started#enabling_apis"><b>Enabling APIs</b></a> in the Google Cloud documentation for more information.</div>
+{{% collapse-content title="Quick Start (recommended)" level="h4" id="quick-start-log-setup" %}}
+#### Choose the Quick Start setup method if…
+
+- You are setting up log forwarding from Google Cloud for the first time.
+- You prefer a UI-based workflow and want to minimize the time it takes to create and configure the necessary resources.
+- You want to automate setup steps in scripts or CI/CD pipelines.
+
+#### Instructions
+
+1. In the [Google Cloud integration tile][100], select the **Log Collection** tab.
+1. Select **Quick Start**. A setup script, configured with your Datadog credentials and site, is automatically generated.
+1. Copy the setup script. You can choose to run the script locally, or in Google Cloud Shell:
+   - Running the script locally may be faster, but requires that you have your Google Cloud credentials available and the [gcloud CLI][101] installed on your machine.
+   - Click **Open Google Cloud Shell** to run the script in the [Google Cloud Shell][102].
+1. After running the script, return to the Google Cloud integration tile.
+1. In the **Select Projects** section, select the folders and projects to forward logs from. If you select a folder, logs are forwarded from all of its child projects.
+   **Note**: Only folders and projects that you have the necessary access and permissions for appear in this section. Likewise, folders and projects without a display name do not appear.
+1. In the **Dataflow Job Configuration** section, specify configuration options for the Dataflow job:
+   - Select deployment settings (Google Cloud region and project to host the created resources---Pub/Sub topics and subscriptions, a log routing sink, a Secret Manager entry, a service account, a Cloud Storage bucket, and a Dataflow job)
+      **Note**: You cannot name the created resources---the script uses predefined names, so it can skip creation if it finds preexisting resources with the same name.
+   - Select scaling settings (number of workers and maximum workers)
+   - Select performance settings (maximum number of parallel requests and batch size)
+   - Select execution options (Streaming Engine is enabled by default; read more about its [benefits][103])
+      **Note**: If you select to enable [Dataflow Prime][104], you cannot configure worker machine type in the **Advanced Configuration** section.
+1. In the **Advanced Configuration** section, optionally specify the machine type for your Dataflow worker VMs. If no machine type is selected, Dataflow automatically chooses an appropriate machine type based on your job requirements. 
+1. Optionally, choose to specify inclusion and exclusion filters using Google Cloud's [logging query language][105].
+1. Review the steps to be executed in the **Complete Setup** section. If everything is satisfactory, click **Complete Setup**.
+
+
+[100]: https://app.datadoghq.com/integrations/gcp
+[101]: https://docs.cloud.google.com/sdk/docs/install
+[102]: https://docs.cloud.google.com/shell/docs
+[103]: https://docs.cloud.google.com/dataflow/docs/streaming-engine#benefits
+[104]: https://docs.cloud.google.com/dataflow/docs/guides/enable-dataflow-prime
+[105]: https://cloud.google.com/logging/docs/view/logging-query-language
+{{% /collapse-content %}}
+
+{{% collapse-content title="Terraform" level="h4" id="terraform-log-setup" %}}
+#### Choose the Terraform setup method if…
+
+- You manage infrastructure as code and want to keep the Datadog Google Cloud integration under version control.
+- You need to configure multiple folders or projects consistently with reusable provider blocks.
+- You want a repeatable, auditable deployment process that fits into your Terraform-managed environment.
+
+#### Instructions
+
+1. In the [Google Cloud integration tile][200], select the **Log Collection** tab.
+1. Select **Terraform**.
+1. In the **Select Projects** section, select the folders and projects to forward logs from. If you select a folder, logs are forwarded from all of its child projects.
+   **Note**: Only folders and projects that you have the necessary access and permissions for appear in this section. Likewise, folders and projects without a display name do not appear.
+1. In the **Dataflow Job Configuration** section, specify configuration options for the Dataflow job:
+   - Select deployment settings (Google Cloud region and project to host the created resources---Pub/Sub topics and subscriptions, a log routing sink, a Secret Manager entry, a service account, a Cloud Storage bucket, and a Dataflow job)
+      **Note**: You cannot name the created resources---the script uses predefined names, so it can skip creation if it finds preexisting resources with the same name.
+   - Select scaling settings (number of workers and maximum workers)
+   - Select performance settings (maximum number of parallel requests and batch size)
+   - Select execution options (Streaming Engine is enabled by default; read more about its [benefits][201])
+      **Note**: If you select to enable [Dataflow Prime][202], you cannot configure worker machine type in the **Advanced Configuration** section.
+1. In the **Advanced Configuration** section, optionally specify the machine type for your Dataflow worker VMs. If no machine type is selected, Dataflow automatically chooses an appropriate machine type based on your job requirements. 
+1. Optionally, choose to specify inclusion and exclusion filters using Google Cloud's [logging query language][203].
+
+
+[200]: https://app.datadoghq.com/integrations/gcp
+[201]: https://docs.cloud.google.com/dataflow/docs/streaming-engine#benefits
+[202]: https://docs.cloud.google.com/dataflow/docs/guides/enable-dataflow-prime
+[203]: https://cloud.google.com/logging/docs/view/logging-query-language
+{{% /collapse-content %}}
+
+{{% collapse-content title="Pub/Sub Push subscription (legacy; not recommended)" level="h4" id="pub-sub-push-logging-setup" %}}
+
+<a href="https://docs.datadoghq.com/logs/guide/collect-google-cloud-logs-with-push/" target="_blank">Collecting Google Cloud logs with a Pub/Sub Push subscription</a> is in the process of being **deprecated**.
+
+The above documentation for the **Push** subscription is only maintained for troubleshooting or modifying legacy setups.
+
+Use a **Pull** subscription with the Datadog Dataflow template as described under [Dataflow Method][105] to forward your Google Cloud logs to Datadog instead.
+{{% /collapse-content %}}
+
+See the [Stream logs from Google Cloud to Datadog][9] guide in the Google Cloud architecture center for a more detailed explanation of the steps and architecture involved in log forwarding. For a deep dive into the benefits of the Pub/Sub to Datadog template, read [Stream your Google Cloud logs to Datadog with Dataflow][17] in the Datadog blog.
+
+### Validation
+
+New logging events delivered to the Cloud Pub/Sub topic appear in the [Datadog Log Explorer][67].
+
+**Note**: You can use the [Google Cloud Pricing Calculator][68] to calculate potential costs.
+
+### Monitor the Cloud Pub/Sub log forwarding
+
+The [Google Cloud Pub/Sub integration][69] provides helpful metrics to monitor the status of the log forwarding:
+
+   - `gcp.pubsub.subscription.num_undelivered_messages` for the number of messages pending delivery
+   - `gcp.pubsub.subscription.oldest_unacked_message_age` for the age of the oldest unacknowledged message in a subscription
+
+Use the metrics above with a [metric monitor][70] to receive alerts for the messages in your input and deadletter subscriptions.
+
+### Monitor the Dataflow pipeline
+
+Use Datadog's [Google Cloud Dataflow integration][71] to monitor all aspects of your Dataflow pipelines. You can see all your key Dataflow metrics on the out-of-the-box dashboard, enriched with contextual data such as information about the GCE instances running your Dataflow workloads, and your Pub/Sub throughput.
+
+You can also use a preconfigured [Recommended Monitor][72] to set up notifications for increases in backlog time in your pipeline. For more information, read [Monitor your Dataflow pipelines with Datadog][73] in the Datadog blog.
 
 ## Leveraging the Datadog Agent
 
@@ -510,3 +607,10 @@
 [64]: https://github.com/GoogleCloudPlatform/terraform-gcp-datadog-integration
 [65]: /integrations/google_cloud_platform/#expanded-bigquery-monitoring
 [66]: https://cloud.google.com/identity/docs/overview
+[67]: https://app.datadoghq.com/logs
+[68]: https://cloud.google.com/products/calculator
+[69]: /integrations/google-cloud-pubsub/
+[70]: /monitors/types/metric/
+[71]: /integrations/google-cloud-dataflow/
+[72]: https://www.datadoghq.com/blog/datadog-recommended-monitors/
+[73]: https://www.datadoghq.com/blog/monitor-dataflow-pipelines-with-datadog/