Publishing and Republishing Images on Horizon 8

After you add an image, you can verify the details and then publish the image. You can also republish an image version.

Publishing an Image

The prerequisites and procedure for publishing an image are shown below.

Prerequisites

Be sure to meet the following prerequisites before publishing an image.

• The Edge gateway is configured and ready.

• Make sure at least one secondary vCenter is added to the provision capacity for storing images.

• Verify that the image is correct and that the image is in the Unpublished state.

• Ensure softwareupdate.omnissa.com is resolvable and reachable from the management and tenant (desktop) subnets using the 443 port over TCP protocol for downloading Horizon Agent-related software used in the system image-creation operations. Ensure that any edge proxy that might be set up in your edges is configured appropriately to allow this URL. Without proper configuration, the republish operation could encounter errors and/or fail.

• Verify that the storage capacity required for the replication of resources across multiple Horizon Edges is configured for the image replication in the Capacity > Replication Storage tab. If NFS is used as the replication storage, ensure that the NFS share is mounted and accessible from each vCenter/ESXi host involved in the publish operation. Only vCenters with the mounted NFS share will appear as valid targets for replication.

• Ensure that the base VM has the necessary certificates for the App Volumes Agent to establish a trusted connection with all specified App Volumes Manager hosts before publishing the image.

Note: Any mismatched credentials (that were provided during Adding an image) can cause the publish to fail.

Horizon Cloud can automatically install the Horizon Agent and App Volumes Agent during the publish workflow. If you need to manually install the Horizon Agent for any reason, ensure you do so before publishing. During the following procedure, deselect the Install toggle.

Procedure

In this procedure, you will publish an image that is in the Ready to Publish state.

1. From the Horizon Universal Console, select Images in the left menu.

2. Select an image that is in the Ready to Publish state.

3. On the Image Details page, select the Image Version and then choose Unpublished > Publish from the dropdown menu. On the Publish Image page, the table shows the edge from where the image is imported and is automatically selected. For each edge, the vCenter image placement preference must be set to indicate to which datastore, network, and cluster the image copy should be delivered to.

   Note: The system remembers the vCenter configuration settings used for the previously published operation. It is NOT recommended to change them when an existing image publishing operation is ongoing.

   If NFS is selected as the replication storage provider, only vCenters where the NFS share is mounted will be available for selection.

4. In the VM Details section, add an appropriate description.

5. In the Image Properties section, add an appropriate description.

6. In the Agent section, select Install Horizon Agent. This results in downloading the latest agent version. However, if the image already has your preferred agents installed in it and you do not want to override an already installed agent, then deselect the Install Horizon Agent toggle.

   The Install Horizon Agent toggle is turned on by default because typically an image will not already have agents installed on it and you will have the publishing operation install the agents. However, if the image already has your preferred agents installed, ensure that you turn off this toggle. When this toggle is turned on and you click Publish, the system will run the agent installation process on the image as part of publishing the image.

7. In the Agent section, supported agent versions (current and previous) are listed, where you can select the appropriate agent version based on the compatibility of Horizon 8 Connection Server version. The agent features are also listed, where you can choose the needed features. It also shows the image copies that will be installed.

8. In the App Volumes Agent section, select Install App Volumes Agent. This action installs the latest App Volumes Agent during the image publish workflow.

   • Select the App Volumes usage mode based on your desktop assignment type.

   • For each selected Edge, provide the App Volumes Manager Host IP address and Host Port.

Note: If virtual machines are configured to enter hibernate or other non-always-on power states, App Volumes might not function correctly when using the Connect to App Volumes Manager configuration. This mode requires the virtual machines to remain available to maintain communication with the App Volumes Manager.

**Important:** If the App Volumes Agent is installed manually and the **Install App Volumes Agent** toggle is turned off, the agent might not function correctly on replicated images across multiple Edges because the App Volumes Manager host information from the source Edge is retained.

9. In the DEM Agent section, activate the toggle to Install DEM Agent. This is toggled OFF by default. Refer to the DEM Agent Installation guide for further configuration information.

  a.  Select **Management mode** based on your requirements.

  b.  Select **Integration mode** and proceed with further configuration as needed.

  c.  If the **Standalone mode** toggle is activated, select **Configure FlexEngine mode**. Then choose between: **Active Directory (AD) Group Policy** or **No Active Directory (AD)**.  **Note:** If No AD is selected, choose the Config File name that was added in the DEM settings for each Edge selected.

  d.  Activate the **Enable Computer Environment** toggle settings and configure the config file name for each Edge that is selected. 

10. Click Publish.

 When NFS is used as the replication staging area, IMS will automatically clean up temporary replication files from the NFS share after the publish operation completes.

Republishing an Image Version

The prerequisites and procedure for republishing an image version are shown below.

Whenever an attempt to publish an image version fails, you do not need to delete the old image. Instead, you can republish the failed image version. The republish option can also be used to publish images to edges and/or providers that were not attempted.

Prerequisites

Be sure to meet the following prerequisites before republishing an image version.

• The image version's status can be partially published, failed, or available.

• Ensure that the Edge gateways corresponding to each of the republish locations are in a connected state.

• Ensure softwareupdate.omnissa.com is resolvable and reachable from the management and tenant (desktop) subnets using the 443 port over TCP protocol for downloading Horizon agent-related software used in the system image-creation operations. Ensure that any edge proxy that might be set up in your edges is configured appropriately to allow this URL. Without proper configuration, the republish operation could encounter errors and/or fail. For more information, refer to Port and Protocol Requirements for Deploying Horizon 8 Edge.

• If you are using Network File System (NFS) as the replication storage mechanism, verify that the NFS file share is mounted on the vCenter Servers associated with all selected edges. Republish cannot proceed using NFS unless the NFS datastore is mounted.

Note: Proxy with and without password authentication is supported while certificate-based proxy is not supported.

Procedure

1. From the Horizon Universal Console, select Images in the left menu.

2. Select the image you want to Republish.

3. On the Image Details page, select the Image Version.

4. Click Republish.

   • On the Republish Image page, a list of target edges are shown to which the image version needs to be republished. The source edge from where the image is imported will be automatically selected, as it is required to publish the image to the source edge.

   • The edges where the image copy was not published during the previous attempt are automatically selected. You can choose to select new edges for expansion. You can leave the pre-selected edges as they are to continue with republishing on the failed edges. As a result, when the republish operation succeeds, the image version will become available.

   • You can also unselect the edges if you don’t need to republish the image version on those edges. Note that as a result, when the republish succeeds, the image version will remain in partially published status.

   • Ensure that during the republish operation for each participating edge, the corresponding vCenter-specific image placement preference is set to indicate to datastore, network, and cluster to which the image copy needs to be delivered.

Note:

• The system remembers the vCenter configuration settings used for the previously published operation. It is NOT recommended to change them when an existing image publishing operation is ongoing.

• The Agent versions and features that were chosen at the time of initial publish, will be retained for the republish operation. For the new edges selected, the default agent features corresponding to the Horizon 8 Connection Server version will be installed.