Install and register Zabbix agent

install.ps1

param(
    $username = 'Admin',
    $password = 'zabbix',
    $zabbixHost = '10.0.0.2'
)

Import-Module .\PS-Zabbix-Host.psm1 -force

$credentials = New-Object System.Management.Automation.PSCredential ($userName, (ConvertTo-SecureString $password -AsPlainText -Force))

Install-ZabbixAgent
$ip = Get-LocalIPAddress
$token = New-ZabbixToken -ZabbixHost $zabbixHost -Credentials $credentials

New-ZabbixHost -ZabbixHost $zabbixHost -Token $token -AgentIPAddress $ip

PS-Zabbix-Host.psm1

function Install-ZabbixAgent {
  <#
    .SYNOPSIS
        Install Zabbix agent for Windows
    .DESCRIPTION
        Downloads Zabbix agent and installs it for Windows x64 OS
    .EXAMPLE
        Install-ZabbixAgent
    .PARAMETER ZabbixServerIPAddress
        Your Zabbix Server IP Address, defaults to allow all connections
  #>

  [CmdletBinding()]
  param (
    [Parameter()]
    [string]$ZabbixServerIPAddress = '0.0.0.0/0'
  )

  # download zabbix agent here C:\Users\<user>\AppData\Local\Temp\2\ZabbixAgent.msi
  $outfile = Join-Path -Path $env:TEMP -ChildPath "ZabbixAgent.msi"
  $logFile = Join-Path -Path $env:TEMP -ChildPath "ZabbixAgentInstallLog.txt"
  $agentFileExist = Test-Path $outfile
  $zabbixAgentInstalled = Get-Service 'Zabbix Agent' -ErrorAction SilentlyContinue

  if (!$agentFileExist) {
    Write-Verbose 'Downloading Zabbix agent 5.0.3 from www.zabbix.com'
    Invoke-WebRequest -Uri "https://www.zabbix.com/downloads/5.0.3/zabbix_agent-5.0.3-windows-amd64-openssl.msi" -OutFile $outfile
  }

  if (!$zabbixAgentInstalled) {
    Write-Verbose 'Installing Zabbix Agent'
    Start-Process -FilePath $outfile -ArgumentList "/l*v $logFile SERVER=$ZabbixServerIPAddress /qb!" -PassThru -Wait
  }

  $agentIsRunning = Test-NetConnection localhost -Port 10050 -InformationLevel Quiet
  Write-Verbose "Zabbix agent is downloaded and installed to $($env:computername). Agent is running on port 10050: $agentIsRunning"
}

function Get-LocalIPAddress {
  (
    Get-NetIPConfiguration |
    Where-Object {
      $null -ne $_.IPv4DefaultGateway -and
      $_.NetAdapter.Status -ne "Disconnected"
    }
  ).IPv4Address.IPAddress
}

function New-ZabbixToken {
  [CmdletBinding()]
  param (
    [Parameter(Mandatory)]
    [string]$ZabbixHost,
    [Parameter(Mandatory)]
    [PSCredential]$Credentials
  )

  $ctype = "application/json"
  $url = "http://$($ZabbixHost)/api_jsonrpc.php"

  $loginBody = @{
    jsonrpc = "2.0"
    method  = "user.login"
    id      = 1
    auth    = $null
    params  = @{
      user     = $Credentials.UserName
      password = $Credentials.GetNetworkCredential().Password
    } 
  } | ConvertTo-Json

  $login = Invoke-RestMethod -Uri $url -Body $loginBody -Method Post -ContentType $ctype
  $token = $login.result
  $token
}

function New-ZabbixHost {
  [CmdletBinding()]
  param (
    [Parameter(Mandatory)]
    [string]$ZabbixHost,
    [Parameter(Mandatory)]
    [string]$Token,
    [Parameter(Mandatory)]
    [string]$AgentIPAddress
  )

  $ctype = "application/json"
  $url = "http://$($ZabbixHost)/api_jsonrpc.php"

  # 10081 = Template OS Windows by Zabbix agent
  $templateId = 10081 

  # 10 = Templates/Operating systems, 6 = Virtual machines
  $groupId = 10

  # 10050 = default
  $zabbixPort = "10050"

  $createHostBody = @{
    jsonrpc = "2.0"
    method  = "host.create"
    id      = 1
    auth    = $Token
    params  = @{
      host       = $env:computername
      interfaces = @(
        @{type  = 1
          main  = 1
          useip = 1
          ip    = $AgentIPAddress
          dns   = ""
          port  = $zabbixPort
        }
      )
      groups     = @(
        @{groupid = $groupId }
      )
      templates  = @(
        @{templateid = $templateId }
      )
    }
  } | ConvertTo-Json -Depth 3

  $res = Invoke-RestMethod -Uri $url -Body $createHostBody -Method Post -ContentType $ctype
  $res.result.hostids
}