quota

Documentation

Overview

Package quota defines state structures for resource quota groups for snaps.

Index

• func ResolveCrossReferences(grps map[string]*Group) error
• type Group
  • func NewGroup(name string, memLimit quantity.Size) (*Group, error)
  • func (grp *Group) CurrentMemoryUsage() (quantity.Size, error)
  • func (grp *Group) NewSubGroup(name string, memLimit quantity.Size) (*Group, error)
  • func (grp *Group) SliceFileName() string
• type QuotaGroupSet
  • func (s *QuotaGroupSet) AddAllNecessaryGroups(grp *Group) error
  • func (s *QuotaGroupSet) AllQuotaGroups() []*Group

Functions

func ResolveCrossReferences

func ResolveCrossReferences(grps map[string]*Group) error

ResolveCrossReferences takes a set of deserialized groups and sets all cross references amongst them using the unexported fields which are not serialized.

Types

type Group

type Group struct {
	// Name is the name of the quota group. This name is used the
	// name of the systemd slice underlying the quota group.
	// Certain names are reserved for future use: system, snapd, root, user.
	// Otherwise names following the same rules as snap names can be used.
	Name string `json:"name,omitempty"`

	// SubGroups is the set of sub-groups that are subject to this quota.
	// Sub-groups have their own limits, subject to the requirement that the
	// highest quota for a sub-group is that of the parent group.
	SubGroups []string `json:"sub-groups,omitempty"`

	// MemoryLimit is the limit of memory available to the processes in the
	// group where if the total used memory of all the processes exceeds the
	// limit, oom-killer is invoked which will start killing processes. The
	// specific behavior of which processes are killed is subject to the
	// ExhaustionBehavior. MemoryLimit is expressed in bytes.
	MemoryLimit quantity.Size `json:"memory-limit,omitempty"`

	// ParentGroup is the the parent group that this group is a child of. If it
	// is empty, then this is a "root" quota group.
	ParentGroup string `json:"parent-group,omitempty"`

	// Snaps is the set of snaps that is part of this quota group. If this is
	// empty then the underlying slice may not exist on the system.
	Snaps []string `json:"snaps,omitempty"`
	// contains filtered or unexported fields
}

Group is a quota group of snaps, services or sub-groups that are all subject to specific resource quotas. The only quota resource types currently supported is memory, but this can be expanded in the future.

func NewGroup

func NewGroup(name string, memLimit quantity.Size) (*Group, error)

NewGroup creates a new top quota group with the given name and memory limit.

func (*Group) CurrentMemoryUsage

func (grp *Group) CurrentMemoryUsage() (quantity.Size, error)

CurrentMemoryUsage returns the current memory usage of the quota group. For quota groups which do not yet have a backing systemd slice on the system ( i.e. quota groups without any snaps in them), the memory usage is reported as 0.

func (*Group) NewSubGroup

func (grp *Group) NewSubGroup(name string, memLimit quantity.Size) (*Group, error)

NewSubGroup creates a new sub group under the current group.

func (*Group) SliceFileName

func (grp *Group) SliceFileName() string

SliceFileName returns the name of the slice file that should be used for this quota group. This name will include all of the group's parents in the name. For example, a group named "bar" that is a child of the "foo" group will have a systemd slice name as "snap.foo-bar.slice". Note that the slice name may differ from the snapd friendly group name, mainly in the case that the group is a sub group.

type QuotaGroupSet

type QuotaGroupSet struct {
	// contains filtered or unexported fields
}

QuotaGroupSet is a set of quota groups, it is used for tracking a set of necessary quota groups using AddAllNecessaryGroups to add groups (and their implicit dependencies), and AllQuotaGroups to enumerate all the quota groups in the set.

func (*QuotaGroupSet) AddAllNecessaryGroups

func (s *QuotaGroupSet) AddAllNecessaryGroups(grp *Group) error

AddAllNecessaryGroups adds all groups that are required for the specified group to be effective to the set. This means all sub-groups of this group, all parent groups of this group, and all sub-trees of any parent groups. This set is the set of quota groups that must exist for this quota group to be fully realized on a system, since all sub-branches of the full tree must exist since this group may share some quota resources with the other branches. There is no support for manipulating group trees while accumulating to a QuotaGroupSet using this.

func (*QuotaGroupSet) AllQuotaGroups

func (s *QuotaGroupSet) AllQuotaGroups() []*Group

AllQuotaGroups returns a flattend list of all quota groups and necessary quota groups that have been added to the set.