If you have ever wanted to deploy stateless VMware vSphere clusters without human intervention, then a new utility that we recently released through VMware Flings program may be of interest. The Host Profiles CLI Fling offers a preview of a new workflow for stateless hosts leveraging Auto Deploy that allows administrators to bring up new compute clusters that are immediately ready to run workloads – no maintenance mode and no remediation required.
Stateless VMware ESXi Compute Clusters Trending Up
VMware vSphere administrators that are tasked with managing large infrastructure estates are turning to Auto Deploy for the ability to standardize on a unified workflow that accommodates not only host deployment, but patching and upgrading as well. Environments that are based on consistent compute, I/O, and storage hardware are prime candidates for the configuration management that Host Profiles and Auto Deploy bring.
Initial Cluster Deployment Workflow Today
Even when host configurations are highly standardized, there are certain settings that must be distinct per host – things like static IP addresses, hostnames, and certain other site-specific requirements such as unique root credentials. For a little more background on these host-specific configuration elements, check out the recent overview on customizations.
When a new host boots up with Auto Deploy and is attached to a host profile requiring customization, the host will be in maintenance mode and will likely display a number of alerts until customization and remediation are complete:
VMware ESXi hosts are typically customized through the vSphere Web Client interface, and vSphere 6.5 introduced a more efficient mechanism by offering offline batch customization through a CSV file.
Despite the improved ability to edit host customizations through CSV, the workflow still requires human intervention in the middle of a cluster deployment. That’s because the host customizations cannot be exported for editing until the stateless hosts have been brought under vCenter Server management.
The key steps for vSphere 6.5 stateless deployments looks like this today:
- Create Auto Deploy rules to specify ESXi image profile, host profile, and cluster location
- Boot hosts and wait for them to appear in the vSphere inventory, in maintenance mode
- Remediate Host Profile using the Web Client and, optionally, CSV batch customization
- Verify that hosts are compliant and ready to run workloads
Upfront Cluster Configuration for Zero-Touch Deployment
What if we changed the sequence of these operations so that no human interaction is required mid-stream?
The goal of the Host Profiles CLI Fling is to show how a vSphere cluster of hosts can be completely pre-configured with all required customizations, before those servers are even dropped off at the loading dock if desirable – all that is required is a unique identifier for each host, such as a MAC address or BIOS UUID.
This command-line utility, called hostprofilescli, works in two phases. Since Host Profiles can be configured in a wide variety of ways, the first step is to extract a configuration template from the target cluster. This ensures all required fields that apply to an arbitrary profile are known and described for the vSphere administrator to work with. That template CSV can be populated manually using a spreadsheet or otherwise generated automatically from a source of configuration management data. Once the cluster is defined in the CSV file, the second step is to import those data to vCenter Server. Behind the scenes, the utility creates placeholder objects in the vSphere inventory and applies the necessary customizations to each one. When the hosts eventually boot onto the Auto Deploy network, they will be joined to vCenter Server – fully-compliant and ready for use.
In the animation below, you can see how the utility is used to extract a template, populate host configuration details, and then import those configurations to vCenter.
The pre-customization workflow summary is as follows:
- Create empty cluster and export host customization template with hostprofilescli
- Populate template with desired host configuration (customizations)
- Import customizations to vCenter Server and specify ESXi image profile using hostprofilescli
- Boot the hosts and observe that they are ready for use, not in maintenance mode
Notice that at no time are Auto Deploy rules required for booting these stateless hosts – the utility takes care of creating necessary associations directly. Besides deploying an entire new cluster, the workflow can just as effectively be used to add a group of hosts to an existing cluster.
Additional Host Profiles CLI Features
This command-line utility also has several other configuration capabilities, such as import/export, setting a root password, and changing the system image cache setting from stateless to stateless cached or stateful. Some of these can be done today using PowerCLI.
VMware Flings are for Previewing Technology
Please note that the primary goal of this command-line utility is to introduce the concept of a different workflow that may appeal to larger customers that do frequent vSphere deployments using Auto Deploy and Host Profiles.
Depending on the feedback we receive regarding this Fling, we will prioritize adding this pre-customization functionality to an officially supported VMware product – most likely to PowerCLI. If you feel this would be valuable, reach out to your Technical Account Manager (TAM) or to me to let us know – I would be happy to speak with you about your vSphere deployment and lifecycle management scenarios.
- Customers that regularly deploy new vSphere clusters are turning to Auto Deploy
- Auto Deploy and Host Profiles work together, and part of the workflow of new stateless deployments involves supplying host-specific configuration settings after the initial network boot
- This new Host Profiles CLI Fling takes the batch customization introduced in vSphere 6.5 one step further and allows it to be done prior to even booting new hardware, for a completely zero-touch cluster deployment