package instancetype

import (
	"errors"
	"fmt"
	"strconv"
	"strings"
	"time"

	"github.com/canonical/lxd/shared"
	"github.com/canonical/lxd/shared/api"
	"github.com/canonical/lxd/shared/units"
	"github.com/canonical/lxd/shared/validate"
)

// InstanceAction indicates the type of action being performed.
type InstanceAction string

// InstanceAction types.
const (
	Stop     InstanceAction = "stop"
	Start    InstanceAction = "start"
	Restart  InstanceAction = "restart"
	Freeze   InstanceAction = "freeze"
	Unfreeze InstanceAction = "unfreeze"
)

// ConfigVolatilePrefix indicates the prefix used for volatile config keys.
const ConfigVolatilePrefix = "volatile."

// ConfigKeyPrefixesAny indicates valid prefixes for configuration options.
var ConfigKeyPrefixesAny = []string{"environment.", "user.", "image.", "cloud-init.ssh-keys."}

// ConfigKeyPrefixesContainer indicates valid prefixes for container configuration options.
var ConfigKeyPrefixesContainer = []string{"linux.sysctl.", "limits.kernel."}

// ValidName validates an instance name. There are different validation rules for instance snapshot names
// so it takes an argument indicating whether the name is to be used for a snapshot or not.
func ValidName(instanceName string, isSnapshot bool) error {
	if isSnapshot {
		parentName, snapshotName, _ := api.GetParentAndSnapshotName(instanceName)
		err := validate.IsHostname(parentName)
		if err != nil {
			return fmt.Errorf("Invalid instance name %q: %w", parentName, err)
		}

		err = ValidSnapName(snapshotName)
		if err != nil {
			return fmt.Errorf("Invalid instance snapshot name %q: %w", snapshotName, err)
		}
	} else {
		err := validate.IsHostname(instanceName)
		if err != nil {
			return fmt.Errorf("Invalid instance name %q: %w", instanceName, err)
		}
	}

	return nil
}

// ValidSnapName validates a snnapshot instance name which must not include the instance prefix.
func ValidSnapName(snapshotName string) error {
	if snapshotName == "" {
		return fmt.Errorf("Invalid instance snapshot name, cannot be empty")
	}

	if snapshotName == ".." {
		return fmt.Errorf("Invalid instance snapshot name %q", snapshotName)
	}

	if strings.ContainsAny(snapshotName, "* /\\") {
		return fmt.Errorf("Invalid instance snapshot name %q: Cannot contain *, spaces, forward or back slashes", snapshotName)
	}

	return nil
}

// IsRootDiskDevice returns true if the given device representation is configured as root disk for
// an instance. It typically get passed a specific entry of api.Instance.Devices.
func IsRootDiskDevice(device map[string]string) bool {
	// Root disk devices also need a non-empty "pool" property, but we can't check that here
	// because this function is used with clients talking to older servers where there was no
	// concept of a storage pool, and also it is used for migrating from old to new servers.
	// The validation of the non-empty "pool" property is done inside the disk device itself.
	if device["type"] == "disk" && device["path"] == "/" && device["source"] == "" {
		return true
	}

	return false
}

// ErrNoRootDisk means there is no root disk device found.
var ErrNoRootDisk = fmt.Errorf("No root device could be found")

// GetRootDiskDevice returns the instance device that is configured as root disk.
// Returns the device name and device config map.
func GetRootDiskDevice(devices map[string]map[string]string) (string, map[string]string, error) {
	var devName string
	var dev map[string]string

	for n, d := range devices {
		if IsRootDiskDevice(d) {
			if devName != "" {
				return "", nil, fmt.Errorf("More than one root device found")
			}

			devName = n
			dev = d
		}
	}

	if devName != "" {
		return devName, dev, nil
	}

	return "", nil, ErrNoRootDisk
}

// HugePageSizeKeys is a list of known hugepage size configuration keys.
var HugePageSizeKeys = [...]string{"limits.hugepages.64KB", "limits.hugepages.1MB", "limits.hugepages.2MB", "limits.hugepages.1GB"}

// HugePageSizeSuffix contains the list of known hugepage size suffixes.
var HugePageSizeSuffix = [...]string{"64KB", "1MB", "2MB", "1GB"}

// InstanceConfigKeysAny is a map of config key to validator. (keys applying to containers AND virtual machines).
var InstanceConfigKeysAny = map[string]func(value string) error{
	// lxdmeta:generate(entities=instance; group=boot; key=boot.autostart)
	// If set to `false`, restore the last state.
	// ---
	//  type: bool
	//  liveupdate: no
	//  shortdesc: Whether to always start the instance when LXD starts
	"boot.autostart": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=boot; key=boot.autostart.delay)
	// The number of seconds to wait after the instance started before starting the next one.
	// ---
	//  type: integer
	//  defaultdesc: `0`
	//  liveupdate: no
	//  shortdesc: Delay after starting the instance
	"boot.autostart.delay": validate.Optional(validate.IsInt64),

	// lxdmeta:generate(entities=instance; group=boot; key=boot.autostart.priority)
	// The instance with the highest value is started first.
	// ---
	//  type: integer
	//  defaultdesc: `0`
	//  liveupdate: no
	//  shortdesc: What order to start the instances in
	"boot.autostart.priority": validate.Optional(validate.IsInt64),

	// lxdmeta:generate(entities=instance; group=boot; key=boot.stop.priority)
	// The instance with the highest value is shut down first.
	// ---
	//  type: integer
	//  defaultdesc: `0`
	//  liveupdate: no
	//  shortdesc: What order to shut down the instances in
	"boot.stop.priority": validate.Optional(validate.IsInt64),

	// lxdmeta:generate(entities=instance; group=boot; key=boot.host_shutdown_timeout)
	// Number of seconds to wait for the instance to shut down before it is force-stopped.
	// ---
	//  type: integer
	//  defaultdesc: `30`
	//  liveupdate: yes
	//  shortdesc: How long to wait for the instance to shut down
	"boot.host_shutdown_timeout": validate.Optional(validate.IsInt64),

	// lxdmeta:generate(entities=instance; group=cloud-init; key=cloud-init.network-config)
	// The content is used as seed value for `cloud-init`.
	// ---
	//  type: string
	//  defaultdesc: `DHCP on eth0`
	//  liveupdate: no
	//  condition: If supported by image
	//  shortdesc: Network configuration for `cloud-init`
	"cloud-init.network-config": validate.Optional(validate.IsYAML),

	// lxdmeta:generate(entities=instance; group=cloud-init; key=cloud-init.user-data)
	// The content is used as seed value for `cloud-init`.
	// ---
	//  type: string
	//  defaultdesc: `#cloud-config`
	//  liveupdate: no
	//  condition: If supported by image
	//  shortdesc: User data for `cloud-init`
	"cloud-init.user-data": validate.Optional(validate.IsCloudInitUserData),

	// lxdmeta:generate(entities=instance; group=cloud-init; key=cloud-init.vendor-data)
	// The content is used as seed value for `cloud-init`.
	// ---
	//  type: string
	//  defaultdesc: `#cloud-config`
	//  liveupdate: no
	//  condition: If supported by image
	//  shortdesc: Vendor data for `cloud-init`
	"cloud-init.vendor-data": validate.Optional(validate.IsCloudInitUserData),

	// lxdmeta:generate(entities=instance; group=cloud-init; key=user.network-config)
	//
	// ---
	//  type: string
	//  defaultdesc: `DHCP on eth0`
	//  liveupdate: no
	//  condition: If supported by image
	//  shortdesc: Legacy version of `cloud-init.network-config`

	// lxdmeta:generate(entities=instance; group=cloud-init; key=user.user-data)
	//
	// ---
	//  type: string
	//  defaultdesc: `#cloud-config`
	//  liveupdate: no
	//  condition: If supported by image
	//  shortdesc: Legacy version of `cloud-init.user-data`

	// lxdmeta:generate(entities=instance; group=cloud-init; key=user.vendor-data)
	//
	// ---
	//  type: string
	//  defaultdesc: `#cloud-config`
	//  liveupdate: no
	//  condition: If supported by image
	//  shortdesc: Legacy version of `cloud-init.vendor-data`

	// lxdmeta:generate(entities=instance; group=miscellaneous; key=cluster.evacuate)
	// The `cluster.evacuate` provides control over how instances are handled when a cluster member is being evacuated.
	//
	// Available Modes:
	//   - `auto` *(default)*: The system will automatically decide the best evacuation method based on the instance's type and configured devices:
	//     + If any device is not suitable for migration, the instance will not be migrated (only stopped).
	//     + Live migration will be used only for virtual machines with the `migration.stateful` setting enabled and for which all its devices can be migrated as well.
	//   - `live-migrate`: Instances are live-migrated to another node. This means the instance remains running and operational during the migration process, ensuring minimal disruption.
	//   - `migrate`: In this mode, instances are migrated to another node in the cluster. The migration process will not be live, meaning there will be a brief downtime for the instance during the migration.
	//   -  `stop`: Instances are not migrated. Instead, they are stopped on the current node.
	//
	// See {ref}`cluster-evacuate` for more information.
	// ---
	//  type: string
	//  defaultdesc: `auto`
	//  liveupdate: no
	//  shortdesc: What to do when evacuating the instance
	"cluster.evacuate": validate.Optional(validate.IsOneOf("auto", "migrate", "live-migrate", "stop")),

	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.cpu)
	// A number or a specific range of CPUs to expose to the instance.
	//
	// See {ref}`instance-options-limits-cpu` for more information.
	// ---
	//  type: string
	//  defaultdesc: 1 (VMs)
	//  liveupdate: yes
	//  shortdesc: Which CPUs to expose to the instance
	"limits.cpu": validate.Optional(validate.IsValidCPUSet),

	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.cpu.nodes)
	// A comma-separated list of NUMA node IDs or ranges to place the instance CPUs on.
	//
	// See {ref}`instance-options-limits-cpu-container` for more information.
	// ---
	//  type: string
	//  liveupdate: yes
	//  shortdesc: Which NUMA nodes to place the instance CPUs on
	"limits.cpu.nodes": validate.Optional(validate.IsValidCPUSet),

	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.disk.priority)
	// Controls how much priority to give to the instance's I/O requests when under load.
	//
	// Specify an integer between 0 and 10.
	// ---
	//  type: integer
	//  defaultdesc: `5` (medium)
	//  liveupdate: yes
	//  shortdesc: Priority of the instance's I/O requests
	"limits.disk.priority": validate.Optional(validate.IsPriority),

	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.memory)
	// Percentage of the host's memory or a fixed value in bytes.
	// Various suffixes are supported.
	//
	// See {ref}`instances-limit-units` for details.
	// ---
	//  type: string
	//  defaultdesc: `1GiB` (VMs)
	//  liveupdate: yes
	//  shortdesc: Usage limit for the host's memory
	"limits.memory": func(value string) error {
		if value == "" {
			return nil
		}

		if strings.HasSuffix(value, "%") {
			num, err := strconv.ParseInt(strings.TrimSuffix(value, "%"), 10, 64)
			if err != nil {
				return err
			}

			if num == 0 {
				return errors.New("Memory limit can't be 0%")
			}

			return nil
		}

		num, err := units.ParseByteSizeString(value)
		if err != nil {
			return err
		}

		if num == 0 {
			return fmt.Errorf("Memory limit can't be 0")
		}

		return nil
	},

	// Caller is responsible for full validation of any raw.* value.

	// lxdmeta:generate(entities=instance; group=raw; key=raw.apparmor)
	// The specified entries are appended to the generated profile.
	// ---
	//  type: blob
	//  liveupdate: yes
	//  shortdesc: AppArmor profile entries
	"raw.apparmor": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=raw; key=raw.idmap)
	// For example: `both 1000 1000`
	// ---
	//  type: blob
	//  liveupdate: no
	//  condition: unprivileged container
	//  shortdesc: Raw idmap configuration
	"raw.idmap": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=security; key=security.devlxd)
	// See {ref}`dev-lxd` for more information.
	// ---
	//  type: bool
	//  defaultdesc: `true`
	//  liveupdate: no
	//  shortdesc: Whether `/dev/lxd` is present in the instance
	"security.devlxd": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.devlxd.images)
	//
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: yes
	//  shortdesc: Controls the availability of the `/1.0/images` API over `devlxd`
	"security.devlxd.images": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.protection.delete)
	//
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: container
	//  shortdesc: Whether to prevent the instance from being deleted
	"security.protection.delete": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.protection.start)
	//
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: container
	//  shortdesc: Whether to prevent the instance from being started
	"security.protection.start": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=snapshots; key=snapshots.schedule)
	// Specify either a cron expression (`<minute> <hour> <dom> <month> <dow>`), a comma-separated list of schedule aliases (`@hourly`, `@daily`, `@midnight`, `@weekly`, `@monthly`, `@annually`, `@yearly`), or leave empty to disable automatic snapshots.
	//
	// ---
	//  type: string
	//  defaultdesc: empty
	//  liveupdate: no
	//  shortdesc: Schedule for automatic instance snapshots
	"snapshots.schedule": validate.Optional(validate.IsCron([]string{"@hourly", "@daily", "@midnight", "@weekly", "@monthly", "@annually", "@yearly", "@startup", "@never"})),

	// lxdmeta:generate(entities=instance; group=snapshots; key=snapshots.schedule.stopped)
	//
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  shortdesc: Whether to automatically snapshot stopped instances
	"snapshots.schedule.stopped": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=snapshots; key=snapshots.pattern)
	// Specify a Pongo2 template string that represents the snapshot name.
	// This template is used for scheduled snapshots and for unnamed snapshots.
	//
	// See {ref}`instance-options-snapshots-names` for more information.
	// ---
	//  type: string
	//  defaultdesc: `snap%d`
	//  liveupdate: no
	//  shortdesc: Template for the snapshot name
	"snapshots.pattern": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=snapshots; key=snapshots.expiry)
	// Specify an expression like `1M 2H 3d 4w 5m 6y`.
	// ---
	//  type: string
	//  liveupdate: no
	//  shortdesc: When snapshots are to be deleted
	"snapshots.expiry": func(value string) error {
		// Validate expression
		_, err := shared.GetExpiry(time.Time{}, value)
		return err
	},

	// lxdmeta:generate(entities=instance; group=miscellaneous; key=ubuntu_pro.guest_attach)
	// Indicate whether the guest should auto-attach Ubuntu Pro at start up.
	// The allowed values are `off`, `on`, and `available`.
	// If set to `off`, it will not be possible for the Ubuntu Pro client in the guest to obtain guest token via `devlxd`.
	// If set to `available`, attachment via guest token is possible but will not be performed automatically by the Ubuntu Pro client in the guest at startup.
	// If set to `on`, attachment will be performed automatically by the Ubuntu Pro client in the guest at startup.
	// To allow guest attachment, the host must be an Ubuntu machine that is Pro attached, and guest attachment must be enabled via the Pro client.
	// To do this, run `pro config set lxd_guest_attach=on`.
	// ---
	// type: string
	// liveupdate: no
	// shortdesc: Whether to auto-attach Ubuntu Pro.
	"ubuntu_pro.guest_attach": validate.Optional(validate.IsOneOf("off", "on", "available")),

	// Volatile keys.

	// lxdmeta:generate(entities=instance; group=volatile; key=volatile.apply_template)
	// The template with the given name is triggered upon next startup.
	// ---
	//  type: string
	//  shortdesc: Template hook
	"volatile.apply_template": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=volatile; key=volatile.base_image)
	// The hash of the image that the instance was created from (empty if the instance was not created from an image).
	// ---
	//  type: string
	//  shortdesc: Hash of the base image
	"volatile.base_image": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=volatile; key=volatile.cloud-init.instance-id)
	//
	// ---
	//  type: string
	//  shortdesc: `instance-id` (UUID) exposed to `cloud-init`
	"volatile.cloud-init.instance-id": validate.Optional(validate.IsUUID),

	// lxdmeta:generate(entities=instance; group=volatile; key=volatile.evacuate.origin)
	// The cluster member that the instance lived on before evacuation.
	// ---
	//  type: string
	//  shortdesc: The origin of the evacuated instance
	"volatile.evacuate.origin": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=volatile; key=volatile.last_state.power)
	//
	// ---
	//  type: string
	//  shortdesc: Instance state as of last host shutdown
	"volatile.last_state.power": validate.IsAny,
	"volatile.last_state.ready": validate.IsBool,
	"volatile.apply_quota":      validate.IsAny,
	// lxdmeta:generate(entities=instance; group=volatile; key=volatile.uuid)
	// The instance UUID is globally unique across all servers and projects.
	// ---
	//  type: string
	//  shortdesc: Instance UUID
	"volatile.uuid": validate.Optional(validate.IsUUID),

	// lxdmeta:generate(entities=instance; group=volatile; key=volatile.uuid.generation)
	// The instance generation UUID changes whenever the instance's place in time moves backwards.
	// It is globally unique across all servers and projects.
	// ---
	//  type: string
	//  shortdesc: Instance generation UUID
	"volatile.uuid.generation": validate.Optional(validate.IsUUID),
}

// InstanceConfigKeysContainer is a map of config key to validator. (keys applying to containers only).
var InstanceConfigKeysContainer = map[string]func(value string) error{
	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.cpu.allowance)
	// To control how much of the CPU can be used, specify either a percentage (`50%`) for a soft limit
	// or a chunk of time (`25ms/100ms`) for a hard limit.
	//
	// See {ref}`instance-options-limits-cpu-container` for more information.
	// ---
	//  type: string
	//  defaultdesc: 100%
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: How much of the CPU can be used
	"limits.cpu.allowance": func(value string) error {
		if value == "" {
			return nil
		}

		if strings.HasSuffix(value, "%") {
			// Percentage based allocation
			_, err := strconv.Atoi(strings.TrimSuffix(value, "%"))
			if err != nil {
				return err
			}

			return nil
		}

		// Time based allocation
		fields := strings.SplitN(value, "/", 2)
		if len(fields) != 2 {
			return fmt.Errorf("Invalid allowance: %s", value)
		}

		_, err := strconv.Atoi(strings.TrimSuffix(fields[0], "ms"))
		if err != nil {
			return err
		}

		_, err = strconv.Atoi(strings.TrimSuffix(fields[1], "ms"))
		if err != nil {
			return err
		}

		return nil
	},

	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.cpu.priority)
	// When overcommitting resources, specify the CPU scheduling priority compared to other instances that share the same CPUs.
	// Specify an integer between 0 and 10.
	//
	// See {ref}`instance-options-limits-cpu-container` for more information.
	// ---
	//  type: integer
	//  defaultdesc: `10` (maximum)
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: CPU scheduling priority compared to other instances
	"limits.cpu.priority": validate.Optional(validate.IsPriority),

	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.hugepages.64KB)
	// Fixed value (in bytes) to limit the number of 64 KB huge pages.
	// Various suffixes are supported (see {ref}`instances-limit-units`).
	//
	// See {ref}`instance-options-limits-hugepages` for more information.
	// ---
	//  type: string
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Limit for the number of 64 KB huge pages
	"limits.hugepages.64KB": validate.Optional(validate.IsSize),

	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.hugepages.1MB)
	// Fixed value (in bytes) to limit the number of 1 MB huge pages.
	// Various suffixes are supported (see {ref}`instances-limit-units`).
	//
	// See {ref}`instance-options-limits-hugepages` for more information.
	// ---
	//  type: string
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Limit for the number of 1 MB huge pages
	"limits.hugepages.1MB": validate.Optional(validate.IsSize),

	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.hugepages.2MB)
	// Fixed value (in bytes) to limit the number of 2 MB huge pages.
	// Various suffixes are supported (see {ref}`instances-limit-units`).
	//
	// See {ref}`instance-options-limits-hugepages` for more information.
	// ---
	//  type: string
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Limit for the number of 2 MB huge pages
	"limits.hugepages.2MB": validate.Optional(validate.IsSize),

	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.hugepages.1GB)
	// Fixed value (in bytes) to limit the number of 1 GB huge pages.
	// Various suffixes are supported (see {ref}`instances-limit-units`).
	//
	// See {ref}`instance-options-limits-hugepages` for more information.
	// ---
	//  type: string
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Limit for the number of 1 GB huge pages
	"limits.hugepages.1GB": validate.Optional(validate.IsSize),

	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.memory.enforce)
	// If the instance's memory limit is `hard`, the instance cannot exceed its limit.
	// If it is `soft`, the instance can exceed its memory limit when extra host memory is available.
	// ---
	//  type: string
	//  defaultdesc: `hard`
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Whether the memory limit is `hard` or `soft`
	"limits.memory.enforce": validate.Optional(validate.IsOneOf("soft", "hard")),

	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.memory.swap)
	//
	// ---
	//  type: bool
	//  defaultdesc: `true`
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Whether to encourage/discourage swapping less used pages for this instance
	"limits.memory.swap": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.memory.swap.priority)
	// Specify an integer between 0 and 10.
	// The higher the value, the less likely the instance is to be swapped to disk.
	// ---
	//  type: integer
	//  defaultdesc: `10` (maximum)
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Prevents the instance from being swapped to disk
	"limits.memory.swap.priority": validate.Optional(validate.IsPriority),
	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.processes)
	// If left empty, no limit is set.
	// ---
	//  type: integer
	//  defaultdesc: empty
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Maximum number of processes that can run in the instance
	"limits.processes": validate.Optional(validate.IsInt64),

	// lxdmeta:generate(entities=instance; group=miscellaneous; key=linux.kernel_modules)
	// Specify the kernel modules as a comma-separated list.
	//
	// The modules are loaded before the instance starts, or they can be loaded by a privileged user if {config:option}`instance-miscellaneous:linux.kernel_modules.load` is set to `ondemand`.
	// ---
	//  type: string
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Kernel modules to load or allow loading
	"linux.kernel_modules": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=miscellaneous; key=linux.kernel_modules.load)
	// This option specifies how to load the kernel modules that are specified in {config:option}`instance-miscellaneous:linux.kernel_modules`.
	// Possible values are `boot` (load the modules when booting the container) and `ondemand` (intercept the `finit_modules()` syscall and allow a privileged user in the container's user namespace to load the modules).
	// ---
	//  type: string
	//  defaultdesc: `boot`
	//  liveupdate: no
	//  condition: container
	//  shortdesc: How to load kernel modules
	"linux.kernel_modules.load": validate.Optional(validate.IsOneOf("boot", "ondemand")),

	// lxdmeta:generate(entities=instance; group=migration; key=migration.incremental.memory)
	// Using incremental memory transfer of the instance's memory can reduce downtime.
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Whether to use incremental memory transfer
	"migration.incremental.memory": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=migration; key=migration.incremental.memory.iterations)
	//
	// ---
	//  type: integer
	//  defaultdesc: `10`
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Maximum number of transfer operations to go through before stopping the instance
	"migration.incremental.memory.iterations": validate.Optional(validate.IsUint32),

	// lxdmeta:generate(entities=instance; group=migration; key=migration.incremental.memory.goal)
	//
	// ---
	//  type: integer
	//  defaultdesc: `70`
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Percentage of memory to have in sync before stopping the instance
	"migration.incremental.memory.goal": validate.Optional(validate.IsUint32),

	// lxdmeta:generate(entities=instance; group=nvidia; key=nvidia.runtime)
	//
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Whether to pass the host NVIDIA and CUDA runtime libraries into the instance
	"nvidia.runtime": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=nvidia; key=nvidia.driver.capabilities)
	// The specified driver capabilities are used to set `libnvidia-container NVIDIA_DRIVER_CAPABILITIES`.
	// ---
	//  type: string
	//  defaultdesc: `compute,utility`
	//  liveupdate: no
	//  condition: container
	//  shortdesc: What driver capabilities the instance needs
	"nvidia.driver.capabilities": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=nvidia; key=nvidia.require.cuda)
	// The specified version expression is used to set `libnvidia-container NVIDIA_REQUIRE_CUDA`.
	// ---
	//  type: string
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Required CUDA version
	"nvidia.require.cuda": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=nvidia; key=nvidia.require.driver)
	// The specified version expression is used to set `libnvidia-container NVIDIA_REQUIRE_DRIVER`.
	// ---
	//  type: string
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Required driver version
	"nvidia.require.driver": validate.IsAny,

	// Caller is responsible for full validation of any raw.* value.

	// lxdmeta:generate(entities=instance; group=raw; key=raw.lxc)
	//
	// ---
	//  type: blob
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Raw LXC configuration to be appended to the generated one
	"raw.lxc": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=raw; key=raw.seccomp)
	//
	// ---
	//  type: blob
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Raw Seccomp configuration
	"raw.seccomp": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=security; key=security.idmap.base)
	// Setting this option overrides auto-detection.
	// ---
	//  type: integer
	//  liveupdate: no
	//  condition: unprivileged container
	//  shortdesc: The base host ID to use for the allocation
	"security.idmap.base": validate.Optional(validate.IsUint32),

	// lxdmeta:generate(entities=instance; group=security; key=security.idmap.isolated)
	// If specified, the idmap used for this instance is unique among instances that have this option set.
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: unprivileged container
	//  shortdesc: Whether to use a unique idmap for this instance
	"security.idmap.isolated": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.idmap.size)
	//
	// ---
	//  type: integer
	//  liveupdate: no
	//  condition: unprivileged container
	//  shortdesc: The size of the idmap to use
	"security.idmap.size": validate.Optional(validate.IsUint32),

	// lxdmeta:generate(entities=instance; group=security; key=security.nesting)
	//
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Whether to support running LXD (nested) inside the instance
	"security.nesting": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.privileged)
	// See {ref}`container-security` for more information.
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Whether to run the instance in privileged mode
	"security.privileged": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.protection.shift)
	// Set this option to `true` to prevent the instance's file system from being UID/GID shifted on startup.
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Whether to protect the file system from being UID/GID shifted
	"security.protection.shift": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.allow)
	// A `\n`-separated list of syscalls to allow.
	// This list must be mutually exclusive with `security.syscalls.deny*`.
	// ---
	//  type: string
	//  liveupdate: no
	//  condition: container
	//  shortdesc: List of syscalls to allow
	"security.syscalls.allow": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.deny_default)
	//
	// ---
	//  type: bool
	//  defaultdesc: `true`
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Whether to enable the default syscall deny
	"security.syscalls.deny_default": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.deny_compat)
	// On `x86_64`, this option controls whether to block `compat_*` syscalls.
	// On other architectures, the option is ignored.
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Whether to block `compat_*` syscalls (`x86_64` only)
	"security.syscalls.deny_compat": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.deny)
	// A `\n`-separated list of syscalls to deny.
	// This list must be mutually exclusive with `security.syscalls.allow`.
	// ---
	//  type: string
	//  liveupdate: no
	//  condition: container
	//  shortdesc: List of syscalls to deny
	"security.syscalls.deny": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.intercept.bpf)
	//
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Whether to handle the `bpf()` system call
	"security.syscalls.intercept.bpf": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.intercept.bpf.devices)
	// This option controls whether to allow BPF programs for the devices cgroup in the unified hierarchy to be loaded.
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Whether to allow BPF programs
	"security.syscalls.intercept.bpf.devices": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.intercept.mknod)
	// These system calls allow creation of a limited subset of char/block devices.
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Whether to handle the `mknod` and `mknodat` system calls
	"security.syscalls.intercept.mknod": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.intercept.mount)
	//
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Whether to handle the `mount` system call
	"security.syscalls.intercept.mount": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.intercept.mount.allowed)
	// Specify a comma-separated list of file systems that are safe to mount for processes inside the instance.
	// ---
	//  type: string
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: File systems that can be mounted
	"security.syscalls.intercept.mount.allowed": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.intercept.mount.fuse)
	// Specify the mounts of a given file system that should be redirected to their FUSE implementation (for example, `ext4=fuse2fs`).
	// ---
	//  type: string
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: File system that should be redirected to FUSE implementation
	"security.syscalls.intercept.mount.fuse": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.intercept.mount.shift)
	//
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: yes
	//  condition: container
	//  shortdesc: Whether to use idmapped mounts for syscall interception
	"security.syscalls.intercept.mount.shift": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.intercept.sched_setscheduler)
	// This system call allows increasing process priority.
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Whether to handle the `sched_setscheduler` system call
	"security.syscalls.intercept.sched_setscheduler": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.intercept.setxattr)
	// This system call allows setting a limited subset of restricted extended attributes.
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Whether to handle the `setxattr` system call
	"security.syscalls.intercept.setxattr": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.syscalls.intercept.sysinfo)
	// This system call can be used to get cgroup-based resource usage information.
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: container
	//  shortdesc: Whether to handle the `sysinfo` system call
	"security.syscalls.intercept.sysinfo": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=volatile; key=volatile.last_state.idmap)
	// The UID/GID map that has been applied to the container's underlying storage.
	// This is usually set for containers created on older kernels that don't
	// support idmapped mounts.
	// ---
	//  type: string
	//  condition: container
	//  shortdesc: On-disk UID/GID map for the container's rootfs
	"volatile.last_state.idmap": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=volatile; key=volatile.idmap.base)
	//
	// ---
	//  type: integer
	//  condition: container
	//  shortdesc: The first ID in the container's primary idmap range
	"volatile.idmap.base": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=volatile; key=volatile.idmap.current)
	//
	// ---
	//  type: string
	//  condition: container
	//  shortdesc: The idmap currently in use by the container
	"volatile.idmap.current": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=volatile; key=volatile.idmap.next)
	//
	// ---
	//  type: string
	//  condition: container
	//  shortdesc: The idmap to use the next time the container starts
	"volatile.idmap.next": validate.IsAny,
}

// InstanceConfigKeysVM is a map of config key to validator. (keys applying to VM only).
var InstanceConfigKeysVM = map[string]func(value string) error{
	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.memory.hugepages)
	// If this option is set to `false`, regular system memory is used.
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: virtual machine
	//  shortdesc: Whether to back the instance using huge pages
	"limits.memory.hugepages": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=resource-limits; key=limits.cpu.pin_strategy)
	// Specify the strategy for VM CPU auto pinning.
	// Possible values: `none` (disables CPU auto pinning) and `auto` (enables CPU auto pinning).
	//
	// See {ref}`instance-options-limits-cpu-vm` for more information.
	// ---
	//  type: string
	//  defaultdesc: `none`
	//  liveupdate: no
	//	condition: virtual machine
	//  shortdesc: VM CPU auto pinning strategy
	"limits.cpu.pin_strategy": validate.Optional(validate.IsOneOf("none", "auto")),

	// lxdmeta:generate(entities=instance; group=migration; key=migration.stateful)
	// Enabling this option prevents the use of some features that are incompatible with it.
	// ---
	//  type: bool
	//  defaultdesc: `false` or value from profiles or `instances.migration.stateful` (if set)
	//  liveupdate: no
	//  condition: virtual machine
	//  shortdesc: Whether to allow for stateful stop/start and snapshots
	"migration.stateful": validate.Optional(validate.IsBool),

	// Caller is responsible for full validation of any raw.* value.

	// lxdmeta:generate(entities=instance; group=raw; key=raw.qemu)
	//
	// ---
	//  type: blob
	//  liveupdate: no
	//  condition: virtual machine
	//  shortdesc: Raw QEMU configuration to be appended to the generated command line
	"raw.qemu": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=raw; key=raw.qemu.conf)
	// See {ref}`instance-options-qemu` for more information.
	// ---
	//  type: blob
	//  liveupdate: no
	//  condition: virtual machine
	//  shortdesc: Addition/override to the generated `qemu.conf` file
	"raw.qemu.conf": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=security; key=security.agent.metrics)
	//
	// ---
	//  type: bool
	//  defaultdesc: `true`
	//  liveupdate: no
	//  condition: virtual machine
	//  shortdesc: Whether the `lxd-agent` is queried for state information and metrics
	"security.agent.metrics": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.csm)
	// When enabling this option, set {config:option}`instance-security:security.secureboot` to `false`.
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: virtual machine
	//  shortdesc: Whether to use a firmware that supports UEFI-incompatible operating systems
	"security.csm": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.secureboot)
	// When disabling this option, consider enabling {config:option}`instance-security:security.csm`.
	// ---
	//  type: bool
	//  defaultdesc: `true`
	//  liveupdate: no
	//  condition: virtual machine
	//  shortdesc: Whether UEFI secure boot is enabled with the default Microsoft keys
	"security.secureboot": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.sev)
	//
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: virtual machine
	//  shortdesc: Whether AMD SEV (Secure Encrypted Virtualization) is enabled for this VM
	"security.sev": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.sev.policy.es)
	//
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: virtual machine
	//  shortdesc: Whether AMD SEV-ES (SEV Encrypted State) is enabled for this VM
	"security.sev.policy.es": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=security; key=security.sev.session.dh)
	//
	// ---
	//  type: string
	//  defaultdesc: `true`
	//  liveupdate: no
	//  condition: virtual machine
	//  shortdesc: The guest owner's `base64`-encoded Diffie-Hellman key
	"security.sev.session.dh": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=security; key=security.sev.session.data)
	//
	// ---
	//  type: string
	//  defaultdesc: `true`
	//  liveupdate: no
	//  condition: virtual machine
	//  shortdesc: The guest owner's `base64`-encoded session blob
	"security.sev.session.data": validate.IsAny,

	// lxdmeta:generate(entities=instance; group=miscellaneous; key=user.*)
	// User keys can be used in search.
	// ---
	//  type: string
	//  liveupdate: no
	//  shortdesc: Free-form user key/value storage

	// lxdmeta:generate(entities=instance; group=miscellaneous; key=agent.nic_config)
	// When set to true, the name and MTU of the default network interfaces inside the virtual machine will match those of the instance devices.
	// ---
	//  type: bool
	//  defaultdesc: `false`
	//  liveupdate: no
	//  condition: virtual machine
	//  shortdesc: Whether to use the name and MTU of the default network interfaces
	"agent.nic_config": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=volatile; key=volatile.apply_nvram)
	//
	// ---
	//  type: bool
	//  shortdesc: Whether to regenerate VM NVRAM the next time the instance starts
	"volatile.apply_nvram": validate.Optional(validate.IsBool),

	// lxdmeta:generate(entities=instance; group=volatile; key=volatile.vsock_id)
	//
	// ---
	//  type: string
	//  shortdesc: Instance `vsock ID` used as of last start
	"volatile.vsock_id": validate.Optional(validate.IsInt64),

	// lxdmeta:generate(entities=instance; group=boot; key=boot.debug_edk2)
	// The instance should use a debug version of the `edk2`.
	// A log file can be found in `$LXD_DIR/logs/<instance_name>/edk2.log`.
	// ---
	//  type: bool
	//  shortdesc: Enable debug version of the `edk2`
	"boot.debug_edk2": validate.Optional(validate.IsBool),
}

// ConfigKeyChecker returns a function that will check whether or not
// a provide value is valid for the associate config key.  Returns an
// error if the key is not known.  The checker function only performs
// syntactic checking of the value, semantic and usage checking must
// be done by the caller.  User defined keys are always considered to
// be valid, e.g. user.* and environment.* keys.
func ConfigKeyChecker(key string, instanceType Type) (func(value string) error, error) {
	f, ok := InstanceConfigKeysAny[key]
	if ok {
		return f, nil
	}

	if instanceType == Any || instanceType == Container {
		f, ok := InstanceConfigKeysContainer[key]
		if ok {
			return f, nil
		}
	}

	if instanceType == Any || instanceType == VM {
		f, ok := InstanceConfigKeysVM[key]
		if ok {
			return f, nil
		}
	}

	// lxdmeta:generate(entities=instance; group=cloud-init; key=cloud-init.ssh-keys.KEYNAME)
	// Represents an additional SSH public key to be merged into existing `cloud-init` seed data
	// and injected into an instance. Has the format `{user}:{key}`, where {user} is a Linux username and
	// {key} can be either a pure SSH public key or an import ID for a key hosted elsewhere.
	// // For example: `root:gh:githubUser`, `myUser:ssh-keyAlg publicKeyHash`
	// ---
	//  type: string
	//  liveupdate: no
	//  condition: If supported by image
	//  shortdesc: Additional SSH key to be injected on the instance by `cloud-init`
	sshKeyName := strings.TrimPrefix(key, "cloud-init.ssh-keys.")
	if sshKeyName != key && sshKeyName != "" {
		return validate.Optional(validate.IsUserSSHKey), nil
	}

	if strings.HasPrefix(key, ConfigVolatilePrefix) {
		// lxdmeta:generate(entities=instance; group=volatile; key=volatile.<name>.last_state.hwaddr)
		// The original MAC that was used when moving a physical device into an instance.
		// ---
		//  type: string
		//  shortdesc: Network device original MAC

		// lxdmeta:generate(entities=instance; group=volatile; key=volatile.<name>.hwaddr)
		// The network device MAC address is used when no `hwaddr` property is set on the device itself.
		// ---
		//  type: string
		//  shortdesc: Network device MAC address

		// lxdmeta:generate(entities=instance; group=volatile; key=volatile.<name>.last_state.vf.hwaddr)
		// The original MAC used when moving a VF into an instance.
		// ---
		//  type: string
		//  shortdesc: SR-IOV virtual function original MAC
		if strings.HasSuffix(key, ".hwaddr") {
			return validate.IsAny, nil
		}

		// lxdmeta:generate(entities=instance; group=volatile; key=volatile.<name>.last_state.vdpa.name)
		// The VDPA device name used when moving a VDPA device file descriptor into an instance.
		// ---
		//  type: string
		//  shortdesc: VDPA device name
		if strings.HasSuffix(key, ".name") {
			return validate.IsAny, nil
		}

		// lxdmeta:generate(entities=instance; group=volatile; key=volatile.<name>.host_name)
		//
		// ---
		//  type: string
		//  shortdesc: Network device name on the host
		if strings.HasSuffix(key, ".host_name") {
			return validate.IsAny, nil
		}

		// lxdmeta:generate(entities=instance; group=volatile; key=volatile.<name>.last_state.mtu)
		// The original MTU that was used when moving a physical device into an instance.
		// ---
		//  type: string
		//  shortdesc: Network device original MTU
		if strings.HasSuffix(key, ".mtu") {
			return validate.IsAny, nil
		}

		// lxdmeta:generate(entities=instance; group=volatile; key=volatile.<name>.last_state.created)
		// Possible values are `true` or `false`.
		// ---
		//  type: string
		//  shortdesc: Whether the network device physical device was created
		if strings.HasSuffix(key, ".created") {
			return validate.IsAny, nil
		}

		// lxdmeta:generate(entities=instance; group=volatile; key=volatile.<name>.last_state.vf.id)
		// The ID used when moving a VF into an instance.
		// ---
		//  type: string
		//  shortdesc: SR-IOV virtual function ID
		if strings.HasSuffix(key, ".id") {
			return validate.IsAny, nil
		}

		// lxdmeta:generate(entities=instance; group=volatile; key=volatile.<name>.last_state.vf.vlan)
		// The original VLAN used when moving a VF into an instance.
		// ---
		//  type: string
		//  shortdesc: SR-IOV virtual function original VLAN
		if strings.HasSuffix(key, ".vlan") {
			return validate.IsAny, nil
		}

		// lxdmeta:generate(entities=instance; group=volatile; key=volatile.<name>.last_state.vf.spoofcheck)
		// The original spoof check setting used when moving a VF into an instance.
		// ---
		//  type: string
		//  shortdesc: SR-IOV virtual function original spoof check setting
		if strings.HasSuffix(key, ".spoofcheck") {
			return validate.IsAny, nil
		}

		if strings.HasSuffix(key, ".last_state.vf.parent") {
			return validate.IsAny, nil
		}

		// lxdmeta:generate(entities=instance; group=volatile; key=volatile.<name>.apply_quota)
		// The disk quota is applied the next time the instance starts.
		// ---
		//  type: string
		//  shortdesc: Disk quota
		if strings.HasSuffix(key, ".apply_quota") {
			return validate.IsAny, nil
		}

		// lxdmeta:generate(entities=instance; group=volatile; key=volatile.<name>.ceph_rbd)
		//
		// ---
		//  type: string
		//  shortdesc: RBD device path for Ceph disk devices
		if strings.HasSuffix(key, ".ceph_rbd") {
			return validate.IsAny, nil
		}

		if strings.HasSuffix(key, ".driver") {
			return validate.IsAny, nil
		}

		// lxdmeta:generate(entities=network-physical; group=volatile; key=volatile.last_state.usb.bus)
		//
		// --
		//  type: string
		//  shortdesc: USB Bus Number
		if strings.HasSuffix(key, ".bus") {
			return validate.IsAny, nil
		}

		// lxdmeta:generate(entities=network-physical; group=volatile; key=volatile.last_state.usb.device)
		//
		// --
		//  type: string
		//  shortdesc: USB Device Number
		if strings.HasSuffix(key, ".device") {
			return validate.IsAny, nil
		}

		if strings.HasSuffix(key, ".uuid") {
			return validate.IsAny, nil
		}

		if strings.HasSuffix(key, ".last_state.ready") {
			return validate.IsBool, nil
		}
	}

	if (instanceType == Any || instanceType == Container) && strings.HasPrefix(key, "linux.sysctl.") {
		return validate.IsAny, nil
	}

	knownPrefixes := append(ConfigKeyPrefixesAny, ConfigKeyPrefixesContainer...)
	if shared.StringHasPrefix(key, knownPrefixes...) {
		return validate.IsAny, nil
	}

	return nil, fmt.Errorf("Unknown configuration key: %q", key)
}

// InstanceIncludeWhenCopying is used to decide whether to include a config item or not when copying an instance.
// The remoteCopy argument indicates if the copy is remote (i.e between LXD nodes) as this affects the keys kept.
func InstanceIncludeWhenCopying(configKey string, remoteCopy bool) bool {
	if configKey == "volatile.base_image" {
		return true // Include volatile.base_image always as it can help optimize copies.
	}

	if configKey == "volatile.last_state.idmap" && !remoteCopy {
		return true // Include volatile.last_state.idmap when doing local copy to avoid needless remapping.
	}

	if strings.HasPrefix(configKey, ConfigVolatilePrefix) {
		return false // Exclude all other volatile keys.
	}

	return true // Keep all other keys.
}
