DeviceRequest

io.k8s.api.resource.v1.DeviceRequest source ↗

DeviceRequest is a request for devices required for a claim. This is typically a request for a single resource like a device, but can also ask for several identical devices. With FirstAvailable it is also possible to provide a prioritized list of requests.

exactlyExactDeviceRequestExactly specifies the details for a single request that must be met exactly for the request to be satisfied.One of Exactly or FirstAvailable must be set.
adminAccessbooleanAdminAccess indicates that this is a claim for administrative access to the device(s). Claims with AdminAccess are expected to be used for monitoring or other management services for a device. They ignore all ordinary claims to the device with respect to access modes and any resource allocations.Admin access is disabled if this field is unset or set to false, otherwise it is enabled.
allocationModestringAllocationMode and its related fields define how devices are allocated to satisfy this request. Supported values are:
  • ExactCount: This request is for a specific number of devices.
This is the default. The exact number is provided in the count field.
  • All: This request is for all of the matching devices in a pool.
At least one device must exist on the node for the allocation to succeed. Allocation will fail if some devices are already allocated, unless adminAccess is requested.If AllocationMode is not specified, the default mode is ExactCount. If the mode is ExactCount and count is not specified, the default count is one. Any other requests must specify this field.More modes may get added in the future. Clients must refuse to handle requests with unknown modes.
capacityCapacityRequirementsCapacity define resource requirements against each capacity.If this field is unset and the device supports multiple allocations, the default value will be applied to each capacity according to requestPolicy. For the capacity that has no requestPolicy, default is the full capacity value.Applies to each device allocation. If Count > 1, the request fails if there aren't enough devices that meet the requirements. If AllocationMode is set to All, the request fails if there are devices that otherwise match the request, and have this capacity, with a value >= the requested amount, but which cannot be allocated to this request.
requestsmap[string]QuantityRequests represent individual device resource requests for distinct resources, all of which must be provided by the device.This value is used as an additional filtering condition against the available capacity on the device. This is semantically equivalent to a CEL selector with `device.capacity[<domain>].<name>.compareTo(quantity(<request quantity>)) >= 0`. For example, device.capacity['test-driver.cdi.k8s.io'].counters.compareTo(quantity('2')) >= 0.When a requestPolicy is defined, the requested amount is adjusted upward to the nearest valid value based on the policy. If the requested amount cannot be adjusted to a valid value—because it exceeds what the requestPolicy allows— the device is considered ineligible for allocation.For any capacity that is not explicitly requested: - If no requestPolicy is set, the default consumed capacity is equal to the full device capacity (i.e., the whole device is claimed).
  • If a requestPolicy is set, the default consumed capacity is determined according to that policy.
If the device allows multiple allocation, the aggregated amount across all requests must not exceed the capacity value. The consumed capacity, which may be adjusted based on the requestPolicy if defined, is recorded in the resource claim’s status.devices[*].consumedCapacity field.
countinteger (int64)Count is used only when the count mode is "ExactCount". Must be greater than zero. If AllocationMode is ExactCount and this field is not specified, the default is one.
deviceClassNamestring requiredDeviceClassName references a specific DeviceClass, which can define additional configuration and selectors to be inherited by this request.A DeviceClassName is required.Administrators may use this to restrict which devices may get requested by only installing classes with selectors for permitted devices. If users are free to request anything without restrictions, then administrators can create an empty DeviceClass for users to reference.
selectors[]DeviceSelectorSelectors define criteria which must be satisfied by a specific device in order for that device to be considered for this request. All selectors must be satisfied for a device to be considered.
celCELDeviceSelectorCEL contains a CEL expression for selecting a device.
expressionstring requiredExpression is a CEL expression which evaluates a single device. It must evaluate to true when the device under consideration satisfies the desired criteria, and false when it does not. Any other result is an error and causes allocation of devices to abort.The expression's input is an object named "device", which carries the following properties:
  • driver (string): the name of the driver which defines this device.
  • attributes (map[string]object): the device's attributes, grouped by prefix
(e.g. device.attributes["dra.example.com"] evaluates to an object with all of the attributes which were prefixed by "dra.example.com".
  • capacity (map[string]object): the device's capacities, grouped by prefix.
  • allowMultipleAllocations (bool): the allowMultipleAllocations property of the device
(v1.34+ with the DRAConsumableCapacity feature enabled).Example: Consider a device with driver="dra.example.com", which exposes two attributes named "model" and "ext.example.com/family" and which exposes one capacity named "modules". This input to this expression would have the following fields:device.driver device.attributes["dra.example.com"].model device.attributes["ext.example.com"].family device.capacity["dra.example.com"].modulesThe device.driver field can be used to check for a specific driver, either as a high-level precondition (i.e. you only want to consider devices from this driver) or as part of a multi-clause expression that is meant to consider devices from different drivers.The value type of each attribute is defined by the device definition, and users who write these expressions must consult the documentation for their specific drivers. The value type of each capacity is Quantity.If an unknown prefix is used as a lookup in either device.attributes or device.capacity, an empty map will be returned. Any reference to an unknown field will cause an evaluation error and allocation to abort.A robust expression should check for the existence of attributes before referencing them.For ease of use, the cel.bind() function is enabled, and can be used to simplify expressions that access multiple attributes with the same domain. For example:cel.bind(dra, device.attributes["dra.example.com"], dra.someBool && dra.anotherBool)When the DRAListTypeAttributes feature gate is enabled, the includes() helper is available and it can work for both scalar and list-type attributes. It was introduced to support smooth migration from scalar attributes to list-type attributes while keeping CEL expressions simple. For example:device.attributes["dra.example.com"].models.includes("some-model")The length of the expression must be smaller or equal to 10 Ki. The cost of evaluating it is also limited based on the estimated number of logical steps.
tolerations[]DeviceTolerationIf specified, the request's tolerations.Tolerations for NoSchedule are required to allocate a device which has a taint with that effect. The same applies to NoExecute.In addition, should any of the allocated devices get tainted with NoExecute after allocation and that effect is not tolerated, then all pods consuming the ResourceClaim get deleted to evict them. The scheduler will not let new pods reserve the claim while it has these tainted devices. Once all pods are evicted, the claim will get deallocated.The maximum number of tolerations is 16.This is a beta field and requires enabling the DRADeviceTaints feature gate.
effectstringEffect indicates the taint effect to match. Empty means match all taint effects. When specified, allowed values are NoSchedule and NoExecute.
keystringKey is the taint key that the toleration applies to. Empty means match all taint keys. If the key is empty, operator must be Exists; this combination means to match all values and all keys. Must be a label name.
operatorstringOperator represents a key's relationship to the value. Valid operators are Exists and Equal. Defaults to Equal. Exists is equivalent to wildcard for value, so that a ResourceClaim can tolerate all taints of a particular category.
tolerationSecondsinteger (int64)TolerationSeconds represents the period of time the toleration (which must be of effect NoExecute, otherwise this field is ignored) tolerates the taint. By default, it is not set, which means tolerate the taint forever (do not evict). Zero and negative values will be treated as 0 (evict immediately) by the system. If larger than zero, the time when the pod needs to be evicted is calculated as <time when taint was adedd> + <toleration seconds>.
valuestringValue is the taint value the toleration matches to. If the operator is Exists, the value must be empty, otherwise just a regular string. Must be a label value.
firstAvailable[]DeviceSubRequestFirstAvailable contains subrequests, of which exactly one will be selected by the scheduler. It tries to satisfy them in the order in which they are listed here. So if there are two entries in the list, the scheduler will only check the second one if it determines that the first one can not be used.DRA does not yet implement scoring, so the scheduler will select the first set of devices that satisfies all the requests in the claim. And if the requirements can be satisfied on more than one node, other scheduling features will determine which node is chosen. This means that the set of devices allocated to a claim might not be the optimal set available to the cluster. Scoring will be implemented later.
allocationModestringAllocationMode and its related fields define how devices are allocated to satisfy this subrequest. Supported values are:
  • ExactCount: This request is for a specific number of devices.
This is the default. The exact number is provided in the count field.
  • All: This subrequest is for all of the matching devices in a pool.
Allocation will fail if some devices are already allocated, unless adminAccess is requested.If AllocationMode is not specified, the default mode is ExactCount. If the mode is ExactCount and count is not specified, the default count is one. Any other subrequests must specify this field.More modes may get added in the future. Clients must refuse to handle requests with unknown modes.
capacityCapacityRequirementsCapacity define resource requirements against each capacity.If this field is unset and the device supports multiple allocations, the default value will be applied to each capacity according to requestPolicy. For the capacity that has no requestPolicy, default is the full capacity value.Applies to each device allocation. If Count > 1, the request fails if there aren't enough devices that meet the requirements. If AllocationMode is set to All, the request fails if there are devices that otherwise match the request, and have this capacity, with a value >= the requested amount, but which cannot be allocated to this request.
requestsmap[string]QuantityRequests represent individual device resource requests for distinct resources, all of which must be provided by the device.This value is used as an additional filtering condition against the available capacity on the device. This is semantically equivalent to a CEL selector with `device.capacity[<domain>].<name>.compareTo(quantity(<request quantity>)) >= 0`. For example, device.capacity['test-driver.cdi.k8s.io'].counters.compareTo(quantity('2')) >= 0.When a requestPolicy is defined, the requested amount is adjusted upward to the nearest valid value based on the policy. If the requested amount cannot be adjusted to a valid value—because it exceeds what the requestPolicy allows— the device is considered ineligible for allocation.For any capacity that is not explicitly requested: - If no requestPolicy is set, the default consumed capacity is equal to the full device capacity (i.e., the whole device is claimed).
  • If a requestPolicy is set, the default consumed capacity is determined according to that policy.
If the device allows multiple allocation, the aggregated amount across all requests must not exceed the capacity value. The consumed capacity, which may be adjusted based on the requestPolicy if defined, is recorded in the resource claim’s status.devices[*].consumedCapacity field.
countinteger (int64)Count is used only when the count mode is "ExactCount". Must be greater than zero. If AllocationMode is ExactCount and this field is not specified, the default is one.
deviceClassNamestring requiredDeviceClassName references a specific DeviceClass, which can define additional configuration and selectors to be inherited by this subrequest.A class is required. Which classes are available depends on the cluster.Administrators may use this to restrict which devices may get requested by only installing classes with selectors for permitted devices. If users are free to request anything without restrictions, then administrators can create an empty DeviceClass for users to reference.
namestring requiredName can be used to reference this subrequest in the list of constraints or the list of configurations for the claim. References must use the format <main request>/<subrequest>.Must be a DNS label.
selectors[]DeviceSelectorSelectors define criteria which must be satisfied by a specific device in order for that device to be considered for this subrequest. All selectors must be satisfied for a device to be considered.
celCELDeviceSelectorCEL contains a CEL expression for selecting a device.
expressionstring requiredExpression is a CEL expression which evaluates a single device. It must evaluate to true when the device under consideration satisfies the desired criteria, and false when it does not. Any other result is an error and causes allocation of devices to abort.The expression's input is an object named "device", which carries the following properties:
  • driver (string): the name of the driver which defines this device.
  • attributes (map[string]object): the device's attributes, grouped by prefix
(e.g. device.attributes["dra.example.com"] evaluates to an object with all of the attributes which were prefixed by "dra.example.com".
  • capacity (map[string]object): the device's capacities, grouped by prefix.
  • allowMultipleAllocations (bool): the allowMultipleAllocations property of the device
(v1.34+ with the DRAConsumableCapacity feature enabled).Example: Consider a device with driver="dra.example.com", which exposes two attributes named "model" and "ext.example.com/family" and which exposes one capacity named "modules". This input to this expression would have the following fields:device.driver device.attributes["dra.example.com"].model device.attributes["ext.example.com"].family device.capacity["dra.example.com"].modulesThe device.driver field can be used to check for a specific driver, either as a high-level precondition (i.e. you only want to consider devices from this driver) or as part of a multi-clause expression that is meant to consider devices from different drivers.The value type of each attribute is defined by the device definition, and users who write these expressions must consult the documentation for their specific drivers. The value type of each capacity is Quantity.If an unknown prefix is used as a lookup in either device.attributes or device.capacity, an empty map will be returned. Any reference to an unknown field will cause an evaluation error and allocation to abort.A robust expression should check for the existence of attributes before referencing them.For ease of use, the cel.bind() function is enabled, and can be used to simplify expressions that access multiple attributes with the same domain. For example:cel.bind(dra, device.attributes["dra.example.com"], dra.someBool && dra.anotherBool)When the DRAListTypeAttributes feature gate is enabled, the includes() helper is available and it can work for both scalar and list-type attributes. It was introduced to support smooth migration from scalar attributes to list-type attributes while keeping CEL expressions simple. For example:device.attributes["dra.example.com"].models.includes("some-model")The length of the expression must be smaller or equal to 10 Ki. The cost of evaluating it is also limited based on the estimated number of logical steps.
tolerations[]DeviceTolerationIf specified, the request's tolerations.Tolerations for NoSchedule are required to allocate a device which has a taint with that effect. The same applies to NoExecute.In addition, should any of the allocated devices get tainted with NoExecute after allocation and that effect is not tolerated, then all pods consuming the ResourceClaim get deleted to evict them. The scheduler will not let new pods reserve the claim while it has these tainted devices. Once all pods are evicted, the claim will get deallocated.The maximum number of tolerations is 16.This is a beta field and requires enabling the DRADeviceTaints feature gate.
effectstringEffect indicates the taint effect to match. Empty means match all taint effects. When specified, allowed values are NoSchedule and NoExecute.
keystringKey is the taint key that the toleration applies to. Empty means match all taint keys. If the key is empty, operator must be Exists; this combination means to match all values and all keys. Must be a label name.
operatorstringOperator represents a key's relationship to the value. Valid operators are Exists and Equal. Defaults to Equal. Exists is equivalent to wildcard for value, so that a ResourceClaim can tolerate all taints of a particular category.
tolerationSecondsinteger (int64)TolerationSeconds represents the period of time the toleration (which must be of effect NoExecute, otherwise this field is ignored) tolerates the taint. By default, it is not set, which means tolerate the taint forever (do not evict). Zero and negative values will be treated as 0 (evict immediately) by the system. If larger than zero, the time when the pod needs to be evicted is calculated as <time when taint was adedd> + <toleration seconds>.
valuestringValue is the taint value the toleration matches to. If the operator is Exists, the value must be empty, otherwise just a regular string. Must be a label value.
namestring requiredName can be used to reference this request in a pod.spec.containers[].resources.claims entry and in a constraint of the claim.References using the name in the DeviceRequest will uniquely identify a request when the Exactly field is set. When the FirstAvailable field is set, a reference to the name of the DeviceRequest will match whatever subrequest is chosen by the scheduler.Must be a DNS label.