Free ESXi Host Management: Open-Source Alternatives to vSphere for VM Operations

While VMware's ESXi hypervisor is technically free to install and use, the management limitations create significant operational challenges. The free version lacks:

vCenter integration
API access for automation
Advanced backup functionality
Role-based access control

The HTML5-based ESXi host client (accessible via https://[ESXi_IP]/ui) provides basic management but has critical restrictions:


// Example: Trying to automate via ESXi free API returns 403
const response = await fetch('https://esxi-host/api/vcenter/vm', {
  headers: {'Authorization': 'Basic ' + btoa('root:password')}
});
// Returns: {"type":"com.vmware.vapi.std.errors.unauthenticated",...}

1. Proxmox VE as Management Frontend

While primarily a KVM solution, Proxmox can manage ESXi hosts through:


# Add ESXi host to Proxmox
pvesh create /nodes --node esxi01 --type vmware \
--hostname 192.168.1.100 --username root --password secret

Limitations: Read-only for VM configuration, but allows power operations.

2. pyVmomi Python Library

VMware's Python SDK works with free ESXi despite official claims:


from pyVmomi import vim
service_instance = connect.SmartConnect(
    host='esxi01.local',
    user='root',
    pwd='password',
    port=443
)
vm = service_instance.content.searchIndex.FindByDnsName(
    None, "ubuntu-vm", True
)
vm.PowerOn()

3. Terraform with ESXi Provider

The community-maintained provider supports basic VM lifecycle operations:


resource "esxi_guest" "ubuntu" {
  guest_name = "ubuntu-20.04"
  disk_store = "datastore1"
  guestos    = "ubuntu-64"
  
  network_interfaces {
    virtual_network = "VM Network"
  }
  
  guest_startup_timeout = 45
}

ghettoVCB Alternative

The unofficial ghettoVCB script still works with ESXi 7/8:


#!/bin/sh
VM_BACKUP_DIR="/vmfs/volumes/datastore1/backups"
VM_LIST="ubuntu-vm centos-vm"

for VM in $VM_LIST; do
  vim-cmd vmsvc/getallvms | grep "$VM" | awk '{print $1}' | \
  xargs -I {} vim-cmd vmsvc/snapshot.create {} "$VM-backup" "" 1 0
  cp -rp "/vmfs/volumes/datastore1/$VM" "$VM_BACKUP_DIR/"
done

For production environments requiring:

Centralized management of >2 hosts
Automated VM provisioning
Snapshot-based backups
Performance monitoring

The Essentials Kit ($576/yr) becomes cost-effective compared to engineering workarounds.

While the solutions above work technically, be aware that:

Automating the free license via API violates VMware's EULA
Community tools may break with ESXi updates
Production support isn't available

While VMware's ESXi hypervisor is technically free to install, the management limitations create significant operational challenges. The free version (officially called "VMware vSphere Hypervisor") restricts:

No vCenter Server integration (limits multi-host management)
No API access for automation (read-only REST API)
Web UI lacks critical VM management features

1. Using the ESXi Embedded Host Client

The HTML5-based host client (accessible via https://[ESXi_IP]/ui) provides basic management capabilities:

# Example: Accessing host client via curl
curl -k https://192.168.1.100/ui -L
# Returns HTML5 interface for single-host management

Supports:
- VM creation/deletion
- Power operations
- Limited configuration changes
- Console access via web browser

2. PowerCLI for Scripted Management

VMware's PowerShell module works with free ESXi (with some limitations):

# Example PowerCLI commands for free ESXi
Connect-VIServer -Server esxi01.local -User root -Password vmware

# Create new VM
New-VM -Name "TestVM" -MemoryGB 4 -DiskGB 40 -CD -GuestId "ubuntu64Guest"

# Start/Stop VMs
Start-VM -VM "TestVM"
Stop-VM -VM "TestVM" -Confirm:$false

3. Alternative Backup Solutions

Commercial tools like Veeam require licensing, but these open-source options work:

ghettoVCB: Community-developed backup script
RVTools: Excel-based VM reporting/export

# ghettoVCB example backup command
./ghettoVCB.sh -f /vmfs/volumes/datastore1/TestVM -a backup -d dryrun

The free ESXi exposes a limited REST API endpoint at https://[ESXi_IP]/rest. Sample Python code:

import requests
from requests.auth import HTTPBasicAuth

esxi_host = "192.168.1.100"
auth = HTTPBasicAuth('root', 'vmware')

# Get VM list
response = requests.get(
    f"https://{esxi_host}/rest/vcenter/vm",
    auth=auth,
    verify=False
)
print(response.json())

Critical limitation: Most write operations return "403 Forbidden" on unlicensed hosts.