scheduler

Documentation

Overview

Package scheduler provides the core interface that Empire uses when interacting with a cluster of machines to run tasks.

Index

• Variables
• func Env(app *App, process *Process) map[string]string
• func Labels(app *App, process *Process) map[string]string
• func Publish(ctx context.Context, stream StatusStream, msg string)
• type App
• type CRONSchedule
• type Exposure
• type ExposureType
• type FakeScheduler
  • func NewFakeScheduler() *FakeScheduler
  • func (m *FakeScheduler) Instances(ctx context.Context, appID string) ([]*Instance, error)
  • func (m *FakeScheduler) Remove(ctx context.Context, appID string) error
  • func (m *FakeScheduler) Restart(ctx context.Context, app *App, ss StatusStream) error
  • func (m *FakeScheduler) Run(ctx context.Context, app *App, p *Process, in io.Reader, out io.Writer) error
  • func (m *FakeScheduler) Scale(ctx context.Context, app string, ptype string, instances uint) error
  • func (m *FakeScheduler) Stop(ctx context.Context, instanceID string) error
  • func (m *FakeScheduler) Submit(ctx context.Context, app *App, ss StatusStream) error
• type HTTPExposure
  • func (e *HTTPExposure) Protocol() string
• type HTTPSExposure
  • func (e *HTTPSExposure) Protocol() string
• type Instance
• type Process
• type Runner
• type Schedule
• type Scheduler
• type Status
  • func (s *Status) String() string
• type StatusStream
• type StatusStreamFunc
  • func (fn StatusStreamFunc) Publish(status Status) error

Variables

var NullStatusStream = StatusStreamFunc(func(status Status) error {
	return nil
})

NullStatusStream a status stream that does nothing.

Functions

func Env

func Env(app *App, process *Process) map[string]string

Env merges the App environment with any environment variables provided in the process.

func Labels

func Labels(app *App, process *Process) map[string]string

Labels merges the App labels with any labels provided in the process.

func Publish

func Publish(ctx context.Context, stream StatusStream, msg string)

Types

type App

type App struct {
	// The id of the app.
	ID string

	// An identifier that represents the version of this release.
	Release string

	// The name of the app.
	Name string

	// The application environment.
	Env map[string]string

	// The application labels.
	Labels map[string]string

	// Process that belong to this app.
	Processes []*Process
}

type CRONSchedule

type CRONSchedule string

CRONSchedule is a Schedule implementation that represents a CRON expression.

type Exposure

type Exposure struct {
	// External means that this process will be exposed to internet facing
	// traffic, as opposed to being internal. How this is used is
	// implementation specific. For ECS, this means that the attached ELB
	// will be "internet-facing".
	External bool

	// The exposure type (e.g. HTTPExposure, HTTPSExposure, TCPExposure).
	Type ExposureType
}

Exposure controls the exposure settings for a process.

type ExposureType

type ExposureType interface {
	Protocol() string
}

Exposure represents a service that a process exposes, like HTTP/HTTPS/TCP or SSL.

type FakeScheduler

type FakeScheduler struct {
	sync.Mutex
	// contains filtered or unexported fields
}

func NewFakeScheduler

func NewFakeScheduler() *FakeScheduler

func (*FakeScheduler) Instances

func (m *FakeScheduler) Instances(ctx context.Context, appID string) ([]*Instance, error)

func (*FakeScheduler) Remove

func (m *FakeScheduler) Remove(ctx context.Context, appID string) error

func (*FakeScheduler) Restart

func (m *FakeScheduler) Restart(ctx context.Context, app *App, ss StatusStream) error

func (*FakeScheduler) Run

func (m *FakeScheduler) Run(ctx context.Context, app *App, p *Process, in io.Reader, out io.Writer) error

func (*FakeScheduler) Scale

func (m *FakeScheduler) Scale(ctx context.Context, app string, ptype string, instances uint) error

func (*FakeScheduler) Stop

func (m *FakeScheduler) Stop(ctx context.Context, instanceID string) error

func (*FakeScheduler) Submit

func (m *FakeScheduler) Submit(ctx context.Context, app *App, ss StatusStream) error

type HTTPExposure

type HTTPExposure struct{}

HTTPExposure represents an HTTP exposure.

func (*HTTPExposure) Protocol

func (e *HTTPExposure) Protocol() string

type HTTPSExposure

type HTTPSExposure struct {
	// The certificate to attach to the process.
	Cert string
}

HTTPSExposure represents an HTTPS exposure

func (*HTTPSExposure) Protocol

func (e *HTTPSExposure) Protocol() string

type Instance

type Instance struct {
	Process *Process

	// The instance ID.
	ID string

	// The State that this Instance is in.
	State string

	// The time that this instance was last updated.
	UpdatedAt time.Time
}

Instance represents an Instance of a Process.

type Process

type Process struct {
	// The type of process.
	Type string

	// The Image to run.
	Image image.Image

	// The Command to run.
	Command []string

	// Environment variables to set.
	Env map[string]string

	// Labels to set on the container.
	Labels map[string]string

	// The amount of RAM to allocate to this process in bytes.
	MemoryLimit uint

	// The amount of CPU to allocate to this process, out of 1024. Maps to
	// the --cpu-shares flag for docker.
	CPUShares uint

	// ulimit -u
	Nproc uint

	// Instances is the desired instances of this service to run.
	Instances uint

	// Exposure is the level of exposure for this process.
	Exposure *Exposure

	// Can be used to setup a CRON schedule to run this task periodically.
	Schedule Schedule
}

type Runner

type Runner interface {
	// Run runs a process.
	Run(ctx context.Context, app *App, process *Process, in io.Reader, out io.Writer) error
}

type Schedule

type Schedule interface{}

Schedule represents a Schedule for scheduled tasks that run periodically.

type Scheduler

type Scheduler interface {
	Runner

	// Submit submits an app, creating it or updating it as necessary.
	// When StatusStream is nil, Submit should return as quickly as possible,
	// usually when the new version has been received, and validated. If
	// StatusStream is not nil, it's recommended that the method not return until
	// the deployment has fully completed.
	Submit(context.Context, *App, StatusStream) error

	// Remove removes the App.
	Remove(ctx context.Context, app string) error

	// Instance lists the instances of a Process for an app.
	Instances(ctx context.Context, app string) ([]*Instance, error)

	// Stop stops an instance. The scheduler will automatically start a new
	// instance.
	Stop(ctx context.Context, instanceID string) error

	// Restart restarts the processes within the App.
	Restart(context.Context, *App, StatusStream) error
}

Scheduler is an interface for interfacing with Services.

type Status

type Status struct {
	// A friendly human readable message about the status change.
	Message string
}

func (*Status) String

func (s *Status) String() string

String implements the fmt.Stringer interface.

type StatusStream

type StatusStream interface {
	// Publish publishes an update to the status stream
	Publish(Status) error
}

StatusStream is an interface for publishing status updates while a scheduler is executing.

type StatusStreamFunc

type StatusStreamFunc func(Status) error

StatusStreamFunc is a function that implements the Statusstream interface

func (StatusStreamFunc) Publish

func (fn StatusStreamFunc) Publish(status Status) error