allocwatcher

Documentation

Overview

Package allocwatcher allows blocking until another allocation - whether running locally or remotely - completes and migrates the allocation directory if necessary.

Index

• func NewAllocWatcher(c Config) (PrevAllocWatcher, PrevAllocMigrator)
• type AllocRunnerMeta
• type Config
• type NoopPrevAlloc
  • func (NoopPrevAlloc) IsMigrating() bool
  • func (NoopPrevAlloc) IsWaiting() bool
  • func (NoopPrevAlloc) Migrate(context.Context, *allocdir.AllocDir) error
  • func (NoopPrevAlloc) Wait(context.Context) error
• type PrevAllocMigrator
• type PrevAllocWatcher
  • func NewGroupAllocWatcher(watchers ...PrevAllocWatcher) PrevAllocWatcher
• type RPCer

Functions

func NewAllocWatcher

func NewAllocWatcher(c Config) (PrevAllocWatcher, PrevAllocMigrator)

NewAllocWatcher creates a PrevAllocWatcher appropriate for whether this alloc's previous allocation was local or remote. If this alloc has no previous alloc then a noop implementation is returned.

Types

type AllocRunnerMeta

type AllocRunnerMeta interface {
	GetAllocDir() *allocdir.AllocDir
	Listener() *cstructs.AllocListener
	Alloc() *structs.Allocation
}

AllocRunnerMeta provides metadata about an AllocRunner such as its alloc and alloc dir.

type Config

type Config struct {
	// Alloc is the current allocation which may need to block on its
	// previous allocation stopping.
	Alloc *structs.Allocation

	// PreviousRunner is non-nil if Alloc has a PreviousAllocation and it is
	// running locally.
	PreviousRunner AllocRunnerMeta

	// PreemptedRunners is non-nil if Alloc has one or more PreemptedAllocations.
	PreemptedRunners map[string]AllocRunnerMeta

	// RPC allows the alloc watcher to monitor remote allocations.
	RPC RPCer

	// Config is necessary for using the RPC.
	Config *config.Config

	// MigrateToken is used to migrate remote alloc dirs when ACLs are
	// enabled.
	MigrateToken string

	Logger hclog.Logger
}

type NoopPrevAlloc

type NoopPrevAlloc struct{}

NoopPrevAlloc does not block or migrate on a previous allocation and never returns an error.

func (NoopPrevAlloc) IsMigrating

func (NoopPrevAlloc) IsMigrating() bool

func (NoopPrevAlloc) IsWaiting

func (NoopPrevAlloc) IsWaiting() bool

func (NoopPrevAlloc) Migrate

func (NoopPrevAlloc) Migrate(context.Context, *allocdir.AllocDir) error

Migrate returns nil immediately.

func (NoopPrevAlloc) Wait

func (NoopPrevAlloc) Wait(context.Context) error

Wait returns nil immediately.

type PrevAllocMigrator

type PrevAllocMigrator interface {
	PrevAllocWatcher

	// IsMigrating returns true if a concurrent caller is in Migrate
	IsMigrating() bool

	// Migrate data from previous alloc
	Migrate(ctx context.Context, dest *allocdir.AllocDir) error
}

PrevAllocMigrator allows AllocRunners to migrate a previous allocation whether or not the previous allocation is local or remote.

type PrevAllocWatcher

type PrevAllocWatcher interface {
	// Wait for previous alloc to terminate
	Wait(context.Context) error

	// IsWaiting returns true if a concurrent caller is blocked in Wait
	IsWaiting() bool
}

PrevAllocWatcher allows AllocRunners to wait for a previous allocation to terminate whether or not the previous allocation is local or remote. See `PrevAllocMigrator` for migrating workloads.

func NewGroupAllocWatcher

func NewGroupAllocWatcher(watchers ...PrevAllocWatcher) PrevAllocWatcher

type RPCer

type RPCer interface {
	// RPC allows retrieving remote allocs.
	RPC(method string, args interface{}, reply interface{}) error
}

RPCer is the interface needed by a prevAllocWatcher to make RPC calls.