Merge branch 'datadog_ci_integration_docs' into 'master'

Add docs for Datadog integration

See merge request gitlab-org/gitlab!64772

doc/integration/datadog.md

+---
+stage: Create
+group: Ecosystem
+info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
+---
+
+# Datadog integration **(FREE)**
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/270123) in GitLab 14.1
+
+This integration allows sending CI/CD pipeline and job information to [Datadog](https://www.datadoghq.com/) for monitoring and troubleshooting of job failures and performance issues using the [CI Visibility](https://app.datadoghq.com/ci) product.
+
+You can find out more information on [Datadog's CI Visibility documentation site](https://docs.datadoghq.com/continuous_integration/).
+
+## How to configure it
+
+The integration is based on [Webhooks](../user/project/integrations/webhooks.md) and it only requires setup on GitLab.
+
+Configure the integration on a project or group by going to **Settings > Integrations > Datadog** for each project or group you want to instrument. You can also activate the integration for the entire GitLab instance.
+
+Fill in the integration configuration settings:
+
+- `Active` enables the integration.
+- `Datadog site` specifies which [Datadog site](https://docs.datadoghq.com/getting_started/site/) to send data to.
+- `API URL` (optional) allows overriding the API URL used for sending data directly, only used in advanced scenarios.
+- `API key` specifies which API key to use when sending data. You can generate one in the [APIs tab](https://app.datadoghq.com/account/settings#api) of the Integrations section on Datadog.
+- `Service` (optional) specifies which service name to attach to each span generated by the integration. Use this to differentiate between GitLab instances.
+- `Env` (optional) specifies which environment (`env` tag) to attach to each span generated by the integration. Use this to differentiate between groups of GitLab instances (i.e. staging vs production).
+
+You can test the integration with the `Test settings` button. After it’s successful, click `Save changes` to finish the integration set up.
+
+Data sent by the integration will be available in the [CI Visibility](https://app.datadoghq.com/ci) section of your Datadog account.

doc/user/project/integrations/overview.md

@@ -32,7 +32,7 @@ Click on the service links to see further configuration instructions and details
 | Campfire                                                  | Connect to chat.                                                                             | **{dotted-circle}** No |
 | [Confluence Workspace](../../../api/services.md#confluence-service) | Replace the link to the internal wiki with a link to a Confluence Cloud Workspace. | **{dotted-circle}** No |
 | [Custom issue tracker](custom_issue_tracker.md)           | Use a custom issue tracker.                                                                  | **{dotted-circle}** No |
-| Datadog                                                   | Trace your GitLab pipelines with Datadog.                                                    | **{check-circle}** Yes |
+| [Datadog](../../../integration/datadog.md)                | Trace your GitLab pipelines with Datadog.                                                    | **{check-circle}** Yes |
 | [Discord Notifications](discord_notifications.md)         | Send notifications about project events to a Discord channel.                                | **{dotted-circle}** No |
 | Drone CI                                                  | Run CI/CD pipelines with Drone.                                                              | **{check-circle}** Yes |
 | [Emails on push](emails_on_push.md)                       | Send commits and diff of each push by email.                                                 | **{dotted-circle}** No |