Add support for host-managed parameter in LXC networks

[halradaideh]

Description

This PR adds support for Proxmox VE 9.1's host-managed parameter in LXC network configurations, enabling creation and management of OCI-based containers.

Problem

Proxmox VE 9.1 introduced support for OCI (Open Container Initiative) images, allowing users to run Docker Hub images as LXC containers. When creating these containers, Proxmox automatically sets a host-managed=1 parameter on network interfaces. The provider rejected this parameter with an error:

Error: proxmox provider error: proxmox API returned new parameter 'host-managed' we cannot process

This prevented users from using OCI images with Terraform.

Changes

Schema Update

• Added host_managed field to LXC network schema as an optional, computed boolean

Validation Enhancement

• Updated AssertNoNonSchemaValues() to handle API keys with hyphens that map to schema keys with underscores
• Provides forward compatibility for similar API parameters

Key Normalization

• Enhanced adaptDeviceToConf() to normalize all keys by replacing hyphens with underscores
• Updated FlattenDevicesList() to normalize keys and convert integer boolean values to actual booleans

Technical Details

Proxmox uses hyphenated keys in the API (host-managed), while Terraform schemas conventionally use underscores (host_managed). Additionally, Proxmox returns boolean values as integers (1/0), requiring type conversion for Terraform's boolean fields.

The changes implement a translation layer that:

1. Normalizes hyphenated API keys to underscored schema keys
2. Converts integer boolean values to actual booleans
3. Maintains backward compatibility with traditional LXC templates

Example

OCI Container (nginx)

resource "proxmox_lxc" "nginx" {
  target_node  = "pve"
  hostname     = "nginx-container"
  ostemplate   = "local:vztmpl/nginx_latest.tar"
  password     = "secure_password"
  unprivileged = true
  start        = true
  
  cores  = 1
  memory = 512
  
  rootfs {
    storage = "local-lvm"
    size    = "2G"
  }
  
  network {
    name   = "eth0"
    bridge = "vmbr0"
    ip     = "dhcp"
  }
}

After applying, the state will show:

network {
  name         = "eth0"
  bridge       = "vmbr0"
  ip           = "dhcp"
  host_managed = true  # Automatically set by Proxmox for OCI containers
}

Traditional Container (Debian)

Traditional containers continue to work as before, with host_managed = false.

Testing

Tested on Proxmox VE 9.1.1 with:

• OCI containers: nginx, redis, postgres
• Traditional templates: Debian 12, Ubuntu 22.04
• CRUD operations: Create, Read, Update, Delete all functional
• State tracking: Correctly reflects host_managed status

Backward Compatibility

Fully backward compatible:

• Existing configurations with traditional templates work without changes
• The host_managed field is optional and computed
• No breaking changes to existing functionality

Dependencies

Requires the corresponding SDK PR: Telmate/proxmox-api-go#530

References

• Proxmox VE 9.1 introduces OCI container support
• man pct documents the host-managed parameter
• API endpoint: GET /nodes/{node}/lxc/{vmid}/config

[jaynis]

I ran into the same problem when trying to create OCI containers and successfully used this MR to overcome it. Would really like to see it merged.