Overview of VMware Horizon DaaS

Will focus on VMware Horizon Desktop-as-a-Service (DaaS) offering that is specifically designed for VMware Service Provider Partners (VSPP).

Horizon DaaS allows Service Providers to:

  • Provide a single management console for provisioning and delivering virtual desktops and applications from the service provider service center
  • Host multi-tenants, providing dedicated compute resources across dedicated or shared VMware vSphere clusters
  • Allows tenants to bring in their own network services (Active Directory, DNS, DHCP, File Servers, etc.) to provide the same level of security and control as if the workloads were running on-premises

High Level DaaS Architecture

Components of VMware Horizon DaaS

Horizon Version Manager applianceHVM Provides orchestration and automation for Horizon DaaS components. The HVM holds the appliance template, and runtime scripts, which allow for the automatic creation of the Service Provider appliances and the Resource Manager appliances. This is a Linux virtual appliance that is deployed from an OVA file in vCenter Server.

Horizon Air Link appliance – Once the HVM appliance is deployed and the template and scripts copied to the machine, the next stage to deploy the HAL appliance from the HVM admin portal. The HAL is responsible for sending API operations to the vCenter Server to create the appliances.

Service Provider appliances – This is deployed as a pair for high availability. The SP provides the Service Provider administrators access to a web-based portal (Service Center) where they can manage the Horizon DaaS environment. This is the main console from where tenants are deployed, which resource cluster they use, as well as creating desktop collections, which are essentially capacity models for virtual desktops.

Resource Manager appliances – Like the SPs, this is deployed by the HAL in a pair. The role of the RM is to provide access and show the hardware resources available from the vCenter Server(s) that is configured for Horizon DaaS. The RM allows the Service Provider administrators to configure the compute resources for the tenants by allocating resources.

Tenant appliances – The tenant appliances (pair) TA are created from the Service Center portal. You configure the settings for the tenant, such as quotas for user licensing and desktop capacity. Per tenant, a pair is being created.

Unified Access Gateway – This is a hardened Linux appliance that is deployed within the DMZ network to provide secure incoming traffic from external environments. External Horizon Clients make a connection to the UAG and do not see the backend environment, it is the UAG that communicates with the backend Horizon environment. The UAG supports multi-factor authentication to provide further security when accessing virtual desktops and applications from the Internet. The new UAGs will have the capability of SSL offloading as seen on ADC Application Delivery Controllers.

Below is the list of official documentation provided by the Vendor. 

[source: vmware.com]

Creating Host groups and adding Hosts to Nagios

Today we are going to discuss on Nagios Host group creation and Host addition for the Nagios platform. The host groups provide clean grouping of the hosts. 

Creating Host Groups in Nagios

  • Create a hostgroups.cfg using the below command

vi /usr/local/nagios/etc/objects/hostgroups.cfg

  • Then add the following to the hostgroups.cfg.

define hostgroup {
         hostgroup_name NAMEOFGROUP
         alias NAMEOFGROUP alias

  • Add the entry in the Nagios.cfg file

nano /usr/local/nagios/etc/nagios.cfg

  • Then, add the below line at the end of the file


  • Finally, we need to add the servers to the host group (as below)

define host {
host_name NAMEOFHOST
address xxx.xxx.xxx.xxx
hostgroups NAMEOFGROUP

  • Also, make sure to restart the nagios service – service nagios restart

Then, we will look at Host addition process

Continue reading “Creating Host groups and adding Hosts to Nagios”

On Agents (Ubuntu)

  • Install the NRPE tools – sudo apt-get install nagios-nrpe-server nagios-plugins
  • After that, need to define the Nagios server address

sudo nano /etc/nagios/nrpe.cfg

  • Then access the “allowed_hosts” section and update as appropiately [i.e: allowed_hosts=, xxx.xxx.xxx.xxx]
  • Save and exit the changes, then restart the NRPE service

sudo systemctl restart nagios-nrpe-server

  • You may verify the NRPE service with the command – /usr/lib/nagios/plugins/check_load -w 15,10,5 -c 30,25,20

On Nagios Server

  • Once you are done with the Agents, you come back to the Nagios server. Even here, we start by installing the NRPE – sudo apt install nagios-nrpe-plugin
  • Then, access the relavent config file and enable “servers” category 

sudo nano /usr/local/nagios/etc/nagios.cfg

  • To enable cfg_dir=/usr/local/nagios/etc/servers simply uncomment the line
  • After that, we need to create custom commands for Monitoring sensors

sudo nano /usr/local/nagios/etc/objects/commands.cfg

  • In the bottom of cfg file, you may add the following (save and close to commit the changes)

define command {
command_name check_nrpe
command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$

  • Next, we need to create a client coniguration file – sudo nano /usr/local/nagios/etc/servers/client.cfg
  • There, you may define the host systems with the required object definitions

NOTE: make sure to verify whether the used syntaxes are correct with the below command. Also please refer the Nagios official documentation

sudo /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

  • Finally, restart the nagios [sudo systemctl restart nagios] service and hopefully you should be seeing the Hosts