Attach an existing UCP cluster

Attach an existing UCP cluster

Starting from UCP 3.3.3, you can attach an existing UCP cluster that is not deployed by Docker Enterprise (DE) Container Cloud to a management cluster. This feature allows for visualization of all your UCP clusters details in one place including clusters health, capacity, and usage.

For supported configurations of existing UCP clusters that are not deployed by DE Container Cloud, see Docker Enterprise Compatibility Matrix.

Note

Using the free Mirantis license, you can create up to three DE Container Cloud managed clusters with three worker nodes on each cluster. Within the same quota, you can also attach existing UCP clusters that are not deployed by DE Container Cloud. If you need to increase this quota, contact Mirantis support for further details.

Using the instruction below, you can also install StackLight to your existing UCP cluster during the attach procedure. For the StackLight system requirements, refer to the Reference Architecture: Requirements of the corresponding cloud provider.

You can also update all your UCP clusters to the latest version once your management cluster automatically updates to a newer version where a new UCP Cluster release with the latest UCP version is available. For details, see Update a managed cluster.

Caution

  • A UCP cluster can be attached to only one management cluster. Attaching a DE Container Cloud-based UCP cluster to another management cluster is not supported.

  • Due to the development limitations, if you detach a UCP cluster that is not deployed by DE Container Cloud, Helm controller and OIDC integration are not deleted.

  • Detaching a DE Container Cloud-based UCP cluster is not supported.

To attach an existing UCP cluster:

  1. Log in to the DE Container Cloud web UI with the writer permissions.

  2. Switch to the required project using the Switch Project action icon located on top of the main left-side navigation panel.

  3. In the Clusters tab, expand the Create Cluster menu and click Attach Existing UCP Cluster.

  4. In the wizard that opens, fill out the form with the following parameters as required:

    1. Configure general settings:

      UCP cluster configuration

      Section

      Parameter

      Description

      General Settings

      Cluster Name

      Specify the cluster name.

      Region

      Select the required cloud provider: OpenStack, AWS, or bare metal.

    2. Upload the UCP client bundle or fill in the fields manually. To download the UCP client bundle, refer to UCP user access: Download client certificates.

    3. Configure StackLight:

      StackLight configuration

      Section

      Parameter name

      Description

      StackLight

      Enable StackLight

      Selected by default. Deselect to skip StackLight deployment.

      Note

      You can also enable, disable, or configure StackLight parameters after deploying a managed cluster. For details, see Change a cluster configuration or Configure StackLight.

      Enable Logging

      Select to deploy the StackLight logging stack. For details about the logging components, see Reference Architecture: StackLight deployment architecture.

      Multiserver Mode

      Select to enable StackLight monitoring in the HA mode. For the differences between HA and non-HA modes, see Reference Architecture: StackLight deployment architecture.

      Elasticsearch

      Retention Time

      The Elasticsearch logs retention period in Logstash.

      Persistent Volume Claim Size

      The Elasticsearch persistent volume claim size.

      Prometheus

      Retention Time

      The Prometheus database retention period.

      Retention Size

      The Prometheus database retention size.

      Persistent Volume Claim Size

      The Prometheus persistent volume claim size.

      Enable Watchdog Alert

      Select to enable the Watchdog alert that fires as long as the entire alerting pipeline is functional.

      Custom Alerts

      Specify alerting rules for new custom alerts or upload a YAML file in the following exemplary format:

      - alert: HighErrorRate
        expr: job:request_latency_seconds:mean5m{job="myjob"} > 0.5
        for: 10m
        labels:
          severity: page
        annotations:
          summary: High request latency
      

      For details, see Official Prometheus documentation: Alerting rules. For the list of the predefined StackLight alerts, see Operations Guide: Available StackLight alerts.

      StackLight Email Alerts

      Enable Email Alerts

      Select to enable the StackLight email alerts.

      Send Resolved

      Select to enable notifications about resolved StackLight alerts.

      Require TLS

      Select to enable transmitting emails through TLS.

      Email alerts configuration for StackLight

      Fill out the following email alerts parameters as required:

      • To - the email address to send notifications to.

      • From - the sender address.

      • SmartHost - the SMTP host through which the emails are sent.

      • Authentication username - the SMTP user name.

      • Authentication password - the SMTP password.

      • Authentication identity - the SMTP identity.

      • Authentication secret - the SMTP secret.

      StackLight Slack Alerts

      Enable Slack alerts

      Select to enable the StackLight Slack alerts.

      Send Resolved

      Select to enable notifications about resolved StackLight alerts.

      Slack alerts configuration for StackLight

      Fill out the following Slack alerts parameters as required:

      • API URL - The Slack webhook URL.

      • Channel - The channel to send notifications to, for example, #channel-for-alerts.

  5. Click Create.

    To view the deployment status, verify the cluster status on the Clusters page. Once the orange blinking dot near the cluster name disappears, the deployment is complete.