api/types/volume/cluster_volume.go
package volume
import (
"github.com/docker/docker/api/types/swarm"
)
// ClusterVolume contains options and information specific to, and only present
// on, Swarm CSI cluster volumes.
type ClusterVolume struct {
// ID is the Swarm ID of the volume. Because cluster volumes are Swarm
// objects, they have an ID, unlike non-cluster volumes, which only have a
// Name. This ID can be used to refer to the cluster volume.
ID string
// Meta is the swarm metadata about this volume.
swarm.Meta
// Spec is the cluster-specific options from which this volume is derived.
Spec ClusterVolumeSpec
// PublishStatus contains the status of the volume as it pertains to its
// publishing on Nodes.
PublishStatus []*PublishStatus `json:",omitempty"`
// Info is information about the global status of the volume.
Info *Info `json:",omitempty"`
}
// ClusterVolumeSpec contains the spec used to create this volume.
type ClusterVolumeSpec struct {
// Group defines the volume group of this volume. Volumes belonging to the
// same group can be referred to by group name when creating Services.
// Referring to a volume by group instructs swarm to treat volumes in that
// group interchangeably for the purpose of scheduling. Volumes with an
// empty string for a group technically all belong to the same, emptystring
// group.
Group string `json:",omitempty"`
// AccessMode defines how the volume is used by tasks.
AccessMode *AccessMode `json:",omitempty"`
// AccessibilityRequirements specifies where in the cluster a volume must
// be accessible from.
//
// This field must be empty if the plugin does not support
// VOLUME_ACCESSIBILITY_CONSTRAINTS capabilities. If it is present but the
// plugin does not support it, volume will not be created.
//
// If AccessibilityRequirements is empty, but the plugin does support
// VOLUME_ACCESSIBILITY_CONSTRAINTS, then Swarmkit will assume the entire
// cluster is a valid target for the volume.
AccessibilityRequirements *TopologyRequirement `json:",omitempty"`
// CapacityRange defines the desired capacity that the volume should be
// created with. If nil, the plugin will decide the capacity.
CapacityRange *CapacityRange `json:",omitempty"`
// Secrets defines Swarm Secrets that are passed to the CSI storage plugin
// when operating on this volume.
Secrets []Secret `json:",omitempty"`
// Availability is the Volume's desired availability. Analogous to Node
// Availability, this allows the user to take volumes offline in order to
// update or delete them.
Availability Availability `json:",omitempty"`
}
// Availability specifies the availability of the volume.
type Availability string
const (
// AvailabilityActive indicates that the volume is active and fully
// schedulable on the cluster.
AvailabilityActive Availability = "active"
// AvailabilityPause indicates that no new workloads should use the
// volume, but existing workloads can continue to use it.
AvailabilityPause Availability = "pause"
// AvailabilityDrain indicates that all workloads using this volume
// should be rescheduled, and the volume unpublished from all nodes.
AvailabilityDrain Availability = "drain"
)
// AccessMode defines the access mode of a volume.
type AccessMode struct {
// Scope defines the set of nodes this volume can be used on at one time.
Scope Scope `json:",omitempty"`
// Sharing defines the number and way that different tasks can use this
// volume at one time.
Sharing SharingMode `json:",omitempty"`
// MountVolume defines options for using this volume as a Mount-type
// volume.
//
// Either BlockVolume or MountVolume, but not both, must be present.
MountVolume *TypeMount `json:",omitempty"`
// BlockVolume defines options for using this volume as a Block-type
// volume.
//
// Either BlockVolume or MountVolume, but not both, must be present.
BlockVolume *TypeBlock `json:",omitempty"`
}
// Scope defines the Scope of a Cluster Volume. This is how many nodes a
// Volume can be accessed simultaneously on.
type Scope string
const (
// ScopeSingleNode indicates the volume can be used on one node at a
// time.
ScopeSingleNode Scope = "single"
// ScopeMultiNode indicates the volume can be used on many nodes at
// the same time.
ScopeMultiNode Scope = "multi"
)
// SharingMode defines the Sharing of a Cluster Volume. This is how Tasks using a
// Volume at the same time can use it.
type SharingMode string
const (
// SharingNone indicates that only one Task may use the Volume at a
// time.
SharingNone SharingMode = "none"
// SharingReadOnly indicates that the Volume may be shared by any
// number of Tasks, but they must be read-only.
SharingReadOnly SharingMode = "readonly"
// SharingOneWriter indicates that the Volume may be shared by any
// number of Tasks, but all after the first must be read-only.
SharingOneWriter SharingMode = "onewriter"
// SharingAll means that the Volume may be shared by any number of
// Tasks, as readers or writers.
SharingAll SharingMode = "all"
)
// TypeBlock defines options for using a volume as a block-type volume.
//
// Intentionally empty.
type TypeBlock struct{}
// TypeMount contains options for using a volume as a Mount-type
// volume.
type TypeMount struct {
// FsType specifies the filesystem type for the mount volume. Optional.
FsType string `json:",omitempty"`
// MountFlags defines flags to pass when mounting the volume. Optional.
MountFlags []string `json:",omitempty"`
}
// TopologyRequirement expresses the user's requirements for a volume's
// accessible topology.
type TopologyRequirement struct {
// Requisite specifies a list of Topologies, at least one of which the
// volume must be accessible from.
//
// Taken verbatim from the CSI Spec:
//
// Specifies the list of topologies the provisioned volume MUST be
// accessible from.
// This field is OPTIONAL. If TopologyRequirement is specified either
// requisite or preferred or both MUST be specified.
//
// If requisite is specified, the provisioned volume MUST be
// accessible from at least one of the requisite topologies.
//
// Given
// x = number of topologies provisioned volume is accessible from
// n = number of requisite topologies
// The CO MUST ensure n >= 1. The SP MUST ensure x >= 1
// If x==n, then the SP MUST make the provisioned volume available to
// all topologies from the list of requisite topologies. If it is
// unable to do so, the SP MUST fail the CreateVolume call.
// For example, if a volume should be accessible from a single zone,
// and requisite =
// {"region": "R1", "zone": "Z2"}
// then the provisioned volume MUST be accessible from the "region"
// "R1" and the "zone" "Z2".
// Similarly, if a volume should be accessible from two zones, and
// requisite =
// {"region": "R1", "zone": "Z2"},
// {"region": "R1", "zone": "Z3"}
// then the provisioned volume MUST be accessible from the "region"
// "R1" and both "zone" "Z2" and "zone" "Z3".
//
// If x<n, then the SP SHALL choose x unique topologies from the list
// of requisite topologies. If it is unable to do so, the SP MUST fail
// the CreateVolume call.
// For example, if a volume should be accessible from a single zone,
// and requisite =
// {"region": "R1", "zone": "Z2"},
// {"region": "R1", "zone": "Z3"}
// then the SP may choose to make the provisioned volume available in
// either the "zone" "Z2" or the "zone" "Z3" in the "region" "R1".
// Similarly, if a volume should be accessible from two zones, and
// requisite =
// {"region": "R1", "zone": "Z2"},
// {"region": "R1", "zone": "Z3"},
// {"region": "R1", "zone": "Z4"}
// then the provisioned volume MUST be accessible from any combination
// of two unique topologies: e.g. "R1/Z2" and "R1/Z3", or "R1/Z2" and
// "R1/Z4", or "R1/Z3" and "R1/Z4".
//
// If x>n, then the SP MUST make the provisioned volume available from
// all topologies from the list of requisite topologies and MAY choose
// the remaining x-n unique topologies from the list of all possible
// topologies. If it is unable to do so, the SP MUST fail the
// CreateVolume call.
// For example, if a volume should be accessible from two zones, and
// requisite =
// {"region": "R1", "zone": "Z2"}
// then the provisioned volume MUST be accessible from the "region"
// "R1" and the "zone" "Z2" and the SP may select the second zone
// independently, e.g. "R1/Z4".
Requisite []Topology `json:",omitempty"`
// Preferred is a list of Topologies that the volume should attempt to be
// provisioned in.
//
// Taken from the CSI spec:
//
// Specifies the list of topologies the CO would prefer the volume to
// be provisioned in.
//
// This field is OPTIONAL. If TopologyRequirement is specified either
// requisite or preferred or both MUST be specified.
//
// An SP MUST attempt to make the provisioned volume available using
// the preferred topologies in order from first to last.
//
// If requisite is specified, all topologies in preferred list MUST
// also be present in the list of requisite topologies.
//
// If the SP is unable to make the provisioned volume available
// from any of the preferred topologies, the SP MAY choose a topology
// from the list of requisite topologies.
// If the list of requisite topologies is not specified, then the SP
// MAY choose from the list of all possible topologies.
// If the list of requisite topologies is specified and the SP is
// unable to make the provisioned volume available from any of the
// requisite topologies it MUST fail the CreateVolume call.
//
// Example 1:
// Given a volume should be accessible from a single zone, and
// requisite =
// {"region": "R1", "zone": "Z2"},
// {"region": "R1", "zone": "Z3"}
// preferred =
// {"region": "R1", "zone": "Z3"}
// then the SP SHOULD first attempt to make the provisioned volume
// available from "zone" "Z3" in the "region" "R1" and fall back to
// "zone" "Z2" in the "region" "R1" if that is not possible.
//
// Example 2:
// Given a volume should be accessible from a single zone, and
// requisite =
// {"region": "R1", "zone": "Z2"},
// {"region": "R1", "zone": "Z3"},
// {"region": "R1", "zone": "Z4"},
// {"region": "R1", "zone": "Z5"}
// preferred =
// {"region": "R1", "zone": "Z4"},
// {"region": "R1", "zone": "Z2"}
// then the SP SHOULD first attempt to make the provisioned volume
// accessible from "zone" "Z4" in the "region" "R1" and fall back to
// "zone" "Z2" in the "region" "R1" if that is not possible. If that
// is not possible, the SP may choose between either the "zone"
// "Z3" or "Z5" in the "region" "R1".
//
// Example 3:
// Given a volume should be accessible from TWO zones (because an
// opaque parameter in CreateVolumeRequest, for example, specifies
// the volume is accessible from two zones, aka synchronously
// replicated), and
// requisite =
// {"region": "R1", "zone": "Z2"},
// {"region": "R1", "zone": "Z3"},
// {"region": "R1", "zone": "Z4"},
// {"region": "R1", "zone": "Z5"}
// preferred =
// {"region": "R1", "zone": "Z5"},
// {"region": "R1", "zone": "Z3"}
// then the SP SHOULD first attempt to make the provisioned volume
// accessible from the combination of the two "zones" "Z5" and "Z3" in
// the "region" "R1". If that's not possible, it should fall back to
// a combination of "Z5" and other possibilities from the list of
// requisite. If that's not possible, it should fall back to a
// combination of "Z3" and other possibilities from the list of
// requisite. If that's not possible, it should fall back to a
// combination of other possibilities from the list of requisite.
Preferred []Topology `json:",omitempty"`
}
// Topology is a map of topological domains to topological segments.
//
// This description is taken verbatim from the CSI Spec:
//
// A topological domain is a sub-division of a cluster, like "region",
// "zone", "rack", etc.
// A topological segment is a specific instance of a topological domain,
// like "zone3", "rack3", etc.
// For example {"com.company/zone": "Z1", "com.company/rack": "R3"}
// Valid keys have two segments: an OPTIONAL prefix and name, separated
// by a slash (/), for example: "com.company.example/zone".
// The key name segment is REQUIRED. The prefix is OPTIONAL.
// The key name MUST be 63 characters or less, begin and end with an
// alphanumeric character ([a-z0-9A-Z]), and contain only dashes (-),
// underscores (_), dots (.), or alphanumerics in between, for example
// "zone".
// The key prefix MUST be 63 characters or less, begin and end with a
// lower-case alphanumeric character ([a-z0-9]), contain only
// dashes (-), dots (.), or lower-case alphanumerics in between, and
// follow domain name notation format
// (https://tools.ietf.org/html/rfc1035#section-2.3.1).
// The key prefix SHOULD include the plugin's host company name and/or
// the plugin name, to minimize the possibility of collisions with keys
// from other plugins.
// If a key prefix is specified, it MUST be identical across all
// topology keys returned by the SP (across all RPCs).
// Keys MUST be case-insensitive. Meaning the keys "Zone" and "zone"
// MUST not both exist.
// Each value (topological segment) MUST contain 1 or more strings.
// Each string MUST be 63 characters or less and begin and end with an
// alphanumeric character with '-', '_', '.', or alphanumerics in
// between.
type Topology struct {
Segments map[string]string `json:",omitempty"`
}
// CapacityRange describes the minimum and maximum capacity a volume should be
// created with
type CapacityRange struct {
// RequiredBytes specifies that a volume must be at least this big. The
// value of 0 indicates an unspecified minimum.
RequiredBytes int64
// LimitBytes specifies that a volume must not be bigger than this. The
// value of 0 indicates an unspecified maximum
LimitBytes int64
}
// Secret represents a Swarm Secret value that must be passed to the CSI
// storage plugin when operating on this Volume. It represents one key-value
// pair of possibly many.
type Secret struct {
// Key is the name of the key of the key-value pair passed to the plugin.
Key string
// Secret is the swarm Secret object from which to read data. This can be a
// Secret name or ID. The Secret data is retrieved by Swarm and used as the
// value of the key-value pair passed to the plugin.
Secret string
}
// PublishState represents the state of a Volume as it pertains to its
// use on a particular Node.
type PublishState string
const (
// StatePending indicates that the volume should be published on
// this node, but the call to ControllerPublishVolume has not been
// successfully completed yet and the result recorded by swarmkit.
StatePending PublishState = "pending-publish"
// StatePublished means the volume is published successfully to the node.
StatePublished PublishState = "published"
// StatePendingNodeUnpublish indicates that the Volume should be
// unpublished on the Node, and we're waiting for confirmation that it has
// done so. After the Node has confirmed that the Volume has been
// unpublished, the state will move to StatePendingUnpublish.
StatePendingNodeUnpublish PublishState = "pending-node-unpublish"
// StatePendingUnpublish means the volume is still published to the node
// by the controller, awaiting the operation to unpublish it.
StatePendingUnpublish PublishState = "pending-controller-unpublish"
)
// PublishStatus represents the status of the volume as published to an
// individual node
type PublishStatus struct {
// NodeID is the ID of the swarm node this Volume is published to.
NodeID string `json:",omitempty"`
// State is the publish state of the volume.
State PublishState `json:",omitempty"`
// PublishContext is the PublishContext returned by the CSI plugin when
// a volume is published.
PublishContext map[string]string `json:",omitempty"`
}
// Info contains information about the Volume as a whole as provided by
// the CSI storage plugin.
type Info struct {
// CapacityBytes is the capacity of the volume in bytes. A value of 0
// indicates that the capacity is unknown.
CapacityBytes int64 `json:",omitempty"`
// VolumeContext is the context originating from the CSI storage plugin
// when the Volume is created.
VolumeContext map[string]string `json:",omitempty"`
// VolumeID is the ID of the Volume as seen by the CSI storage plugin. This
// is distinct from the Volume's Swarm ID, which is the ID used by all of
// the Docker Engine to refer to the Volume. If this field is blank, then
// the Volume has not been successfully created yet.
VolumeID string `json:",omitempty"`
// AccessibleTopolgoy is the topology this volume is actually accessible
// from.
AccessibleTopology []Topology `json:",omitempty"`
}