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Updating Contrail Networking using the Zero Impact Upgrade Process in an Environment using Red Hat Openstack 16.1

This document provides the steps needed to update a Contrail Networking deployment that is using Red Hat Openstack 16.1 as it’s orchestration platform. The procedure provides a zero impact upgrade (ZIU) with minimal disruption to network operations.

If you are using Contrail Networking in an environment that is using a Red Hat Openstack 13-based release, see Updating Contrail Networking using the Zero Impact Upgrade Process in an Environment using Red Hat Openstack 13.

When to Use This Procedure

This procedure is used to upgrade Contrail Networking when it is running in environments using RHOSP version 16.1 (RHOSP16.1).

The procedure in this document has been validated for the following Contrail Networking upgrade scenarios:

Table 1: Contrail Networking with RHOSP16.1 Validated Upgrade Scenarios

Starting Contrail Networking Release

Target Upgraded Contrail Networking Release

2011.L1 or any later 2011.L release

2011.L2 or any later 2011.L release

2011.L1 or any later 2011.L release

Any 21.3 Release

A different procedure is followed for upgrading Contrail Networking in environments using Red Hat Openstack 13. See Updating Contrail Networking using the Zero Impact Upgrade Process in an Environment using Red Hat Openstack 13.


This document makes the following assumptions about your environment:

  • A Contrail Networking deployment using Red Hat Openstack version 16.1 (RHOSP16.1) as the orchestration platform is already operational.

  • The overcloud nodes in the RHOSP16.1 environment have an enabled Red Hat Enterprise Linux (RHEL) subscription.

  • Your environment is running Contrail Release 2011.L1 and upgrading to Contrail Release 2011.L2 or later.

  • If you are updating Red Hat Openstack simultaneously with Contrail Networking, we assume that the undercloud node is updated to the latest minor version and that new overcloud images are prepared for an upgrade. See the Upgrading the Undercloud section of the Keeping Red Hat OpenStack Platform Updated guide from Red Hat.

    If the undercloud has been updated and a copy of the heat templates are used for the deployment, update the copy of the heat template from the Red Hat’s core heat template collection at /usr/share/openstack-tripleo-heat-templates. See the Understanding Heat Templates document from Red Hat for information on this process.

Before You Begin

We recommend performing these procedures before starting the update:

Updating Contrail Networking in an Environment using Red Hat Openstack 16.1

To update Contrail Networking in an environment that is using Red Hat Openstack 16.1 as the orchestration platform:

  1. Prepare your container registry. The registry is often included in the undercloud, but it can also be a separate node.
  2. Backup the Contrail TripleO Heat Templates. See Using the Contrail Heat Template.
  3. Get the Contrail TripleO Heat Templates (Stable/Train branch) from

    Prepare the new tripleo-heat-templates with latest available software from Openstack and Contrail Networking.

  4. Update the parameter ContrailImageTag to the new version.

    The location of the ContrailImageTag variable varies by environment. In the most commonly-used environments, this variable is set in the contrail-services.yaml file.

    You can obtain the ContrailImageTag parameter from the README Access to Contrail Registry 20XX.


    If you are using the undercloud as a registry, ensure the new contrail image is updated in undercloud before proceeding further.

  5. Update the overcloud by entering the openstack overcloud update prepare command and include the files that were updated during the previous steps with the overcloud update.


  6. Prepare the overcloud nodes that include Contrail containers for the update.
    • Pull the images in the repository onto the overcloud nodes.

      There are multiple methods for performing this step. Commonly used methods for performing this operation include using the podman pull command for Docker containers and the openstack overcloud container image upload command for Openstack containers, or running the tripleo-heat-templates/ and tools/contrail/ scripts.

    • (Not required in all setups) Provide export variables for the script if the predefined values aren’t appropriate for your environment. The script location:

      The following variables within the script are particularly significant for this upgrade:

      • CONTRAIL_NEW_IMAGE_TAG—The image tag of the target upgrade version of Contrail. The default value is latest.

        If needed, you can obtain this parameter for a specific image from the README Access to Contrail Registry 20XX.


        Some older deployments use the CONTRAIL_IMAGE_TAG variable in place of the CONTRAIL_NEW_IMAGE_TAG variable. Both variables are recognized by the script and perform the same function.

      • SSH_USER—The SSH username for logging into overcloud nodes. The default value is heat-admin.

      • SSH_OPTIONS—Custom SSH option values.

        The default SSH options for your environment are typically pre-defined. You are typically only changing this value if you want to customize your update.

      • STOP_CONTAINERS—The list of containers that must be stopped before the upgrade can proceed. The default value is contrail_config_api contrail_analytics_api.

    • Run the script:


      Contrail services stop working when the script starts running.

  7. Update the Contrail Controller nodes:
    • Run the openstack overcloud update run command on the first Contrail controller and, if needed, on a Contrail Analytics node. The purpose of this step is to update one Contrail Controller and one Contrail Analytics node to support the environment so the other Contrail Controllers and analytics nodes can be updated without incurring additional downtime.


      Ensure that the contrail status is ok on overcloud-contrailcontroller-0 before proceeding.

      If the analytics and the analyticsdb nodes are on separate nodes, you may have to update the nodes individually:

    • After the upgrade, check the docker container status and versions for the Contrail Controllers and the Contrail Analytics and AnalyticsDB nodes.

    • Update the remaining Contrail Controller nodes:


  8. Update the Openstack Controllers using the openstack overcloud update run commands:


  9. Individually update the compute nodes.

    The compute node agent will be down during this step. The estimated downtime varies by environment, but is typically between 1 and 5 minutes.

    Consider migrating workloads that can’t tolerate this downtime before performing this step

    Reboot your compute node to complete the update.


    A reboot is required to complete this procedure only if a kernel update is also needed. If you would like to avoid rebooting your compute node, check the log files in the /var/log/yum.log file to see if kernel packages were updated during the compute node update. A reboot is required only if kernel updates occurred as part of the compute node update procedure.

    Use the contrail-status command to monitor upgrade status. Ensure all pods reach the running state and all services reach the active state.

    This contrail-status command provides output after a successful upgrade:


    Some output fields and data have been removed from this contrail-status command sample for readability.

  10. Enter the openstack overcloud update converge command to finalize the update.

    The options used in the openstack overcloud update converge in this step will match the options used with the openstack overcloud update prepare command entered in 5.

    Monitor screen messages indicating SUCCESS to confirm that the updates made in this step are successful.