In environments with many hosts, managing hosts with scripts is faster and less error prone than managing the hosts from the vSphere Web Client.

vSphere includes several scripting languages for host management. See the vSphere Command-Line Documentation and the vSphere API/SDK Documentation for reference information and programming tips and VMware Communities for additional tips about scripted management. The vSphere Administrator documentation focuses on using the vSphere Web Client for management.
vSphere PowerCLI

VMware vSphere PowerCLI is a Windows PowerShell interface to the vSphere API. vSphere PowerCLI includes PowerShell cmdlets for administering vSphere components.

vSphere PowerCLI includes more than 200 cmdlets, a set of sample scripts, and a function library for management and automation. See the vSphere PowerCLI Documentation.

vSphere Command-Line Interface (vCLI)
vCLI includes a set of commands for managing ESXi hosts and virtual machines. The installer, which also installs the vSphere SDK for Perl, runs Windows or Linux systems and installs ESXCLI commands, vicfg- commands, and a set of other vCLI commands. See vSphere Command-Line Interface Documentation.

Starting with vSphere 6.0, you can also use one of the scripting interfaces to the vCloud Suite SDK such as the vCloud Suite SDK for Python.

Procedure

  1. Create a custom role that has limited privileges.
    For example, consider creating a role that has a set of privileges for managing hosts but no privileges for managing virtual machines, storage, or networking. If the script you want to use only extracts information, you can create a role with read-only privileges for the host.
  2. From the vSphere Web Client, create a service account and assign it the custom role.
    You can create multiple custom roles with different levels of access if you want access to certain hosts to be fairly limited.
  3. Write scripts to perform parameter checking or modification, and run them.
    For example, you can check or set the shell interactive timeout of a host as follows:
    Language Commands
    vCLI (ESXCLI) 
    esxcli <conn_options> system settings advanced get /UserVars/ESXiShellTimeOut
    esxcli --formatter=csv --format-param=fields="Path,Int Value" 
system settings advanced list | grep /UserVars/ESXiShellTimeOut
    PowerCLI 
    #List UserVars.ESXiShellInteractiveTimeOut for each host
Get-VMHost | Select Name,
 @{N="UserVars.ESXiShellInteractiveTimeOut";E={$_ 
| Get-AdvancedSetting -Name UserVars.ESXiShellInteractiveTimeOut
| Select -ExpandProperty Value}}

# Set UserVars.ESXiShellTimeOut to 900 on all hosts
Get-VMHost 
| Foreach { Get-AdvancedSetting -Entity $_ -Name UserVars.ESXiShellInteractiveTimeOut | Set-AdvancedSetting -Value 900 }
  4. In large environments, create roles with different access privileges and group hosts into folders according to the tasks that you want to perform. You can then run scripts over different folders from different service accounts.
  5. Verify that the changes happened after you run the command.