engine

README

Engine Design Doc

Engine is primarily a for loop that takes inputs from a variety of sources, updates state, and makes a decision based off of that state. The rough shape of the for loop is as follows:

state := &state{}
for {
    select {
        // sources like local filesystem, kubernetes, ui, etc
        case ev := <- fsCh:
            e.handleFsEvent(ev)
        case ev := <- k8sCh:
            e.handleK8sEvent(ev)
    }
    // decide what to do: start a pipeline, stop a pipeline
    actions := handle(state)
    // tell subscribers what we took
    updateSubscribers(actions, state.copy())
}

When state changes, and only when state changes, can we make decisions about what to do. Only after actions have been taken do we tell subscribers.

Rules

• No blocking I/O in the for loop
• No long operations in the for loop
• Actions taken in handle shouldn’t directly send to channels that this for selects on.

Documentation

Index

• Constants
• Variables
• func NewErrorAction(err error) store.ErrorAction
• func ProvideSubscribers(hudsc *server.HeadsUpServerController, ...) []store.Subscriber
• func ProvideSubscribersAPIOnly(hudsc *server.HeadsUpServerController, ...) []store.Subscriber
• func SpanIDForBuildLog(buildCount int) logstore.SpanID
• type BuildController
  • func NewBuildController(b buildcontrol.BuildAndDeployer) *BuildController
  • func (c *BuildController) DisableForTesting()
  • func (c *BuildController) OnChange(ctx context.Context, st store.RStore, summary store.ChangeSummary) error
• type BuildOrder
  • func DefaultBuildOrder(ibad *buildcontrol.ImageBuildAndDeployer, ...) BuildOrder
  • func (bo BuildOrder) String() string
• type CompositeBuildAndDeployer
  • func NewCompositeBuildAndDeployer(builders BuildOrder, tracer trace.Tracer) *CompositeBuildAndDeployer
  • func (composite *CompositeBuildAndDeployer) BuildAndDeploy(ctx context.Context, st store.RStore, specs []model.TargetSpec, ...) (store.BuildResultSet, error)
• type FallbackTester
• type HudStoppedAction
  • func NewHudStoppedAction(err error) HudStoppedAction
  • func (HudStoppedAction) Action()
• type InitAction
  • func (InitAction) Action()
• type ManifestReloadedAction
  • func (ManifestReloadedAction) Action()
• type PodWatcherMaker
• type ServiceWatcherMaker
• type TelemetryScriptRanAction
  • func (TelemetryScriptRanAction) Action()
• type UIDUpdateAction
  • func (UIDUpdateAction) Action()
• type Upper
  • func NewUpper(ctx context.Context, st *store.Store, subs []store.Subscriber) (Upper, error)
  • func (u Upper) Dispatch(action store.Action)
  • func (u Upper) Init(ctx context.Context, action InitAction) error
  • func (u Upper) Start(ctx context.Context, args []string, b model.TiltBuild, fileName string, ...) error

Constants

const BuildControlSource = "buildcontrol"

Variables

var DeployerBaseWireSet = wire.NewSet(buildcontrol.BaseWireSet, wire.Value(UpperReducer), DefaultBuildOrder, wire.Bind(new(buildcontrol.BuildAndDeployer), new(*CompositeBuildAndDeployer)), NewCompositeBuildAndDeployer)

var DeployerWireSet = wire.NewSet(
	DeployerBaseWireSet,
)

var DeployerWireSetTest = wire.NewSet(
	DeployerBaseWireSet, wire.InterfaceValue(new(trace.SpanExporter), (trace.SpanExporter)(nil)),
)

var UpperReducer = store.Reducer(upperReducerFn)

Functions

func NewErrorAction

func NewErrorAction(err error) store.ErrorAction

func ProvideSubscribers

func ProvideSubscribers(
	hudsc *server.HeadsUpServerController,
	tscm *controllers.TiltServerControllerManager,
	cb *controllers.ControllerBuilder,
	hud hud.HeadsUpDisplay,
	ts *hud.TerminalStream,
	tp *prompt.TerminalPrompt,
	sw *k8swatch.ServiceWatcher,
	bc *BuildController,
	cc *configs.ConfigsController,
	tqs *configs.TriggerQueueSubscriber,
	ar *analytics.AnalyticsReporter,
	au *analytics.AnalyticsUpdater,
	ewm *k8swatch.EventWatchManager,
	tcum *cloud.CloudStatusManager,
	dp *dockerprune.DockerPruner,
	tc *telemetry.Controller,
	lsc *local.ServerController,
	podm *k8srollout.PodMonitor,
	sc *session.Controller,
	uss *uisession.Subscriber,
	urs *uiresource.Subscriber,
) []store.Subscriber

func ProvideSubscribersAPIOnly

func ProvideSubscribersAPIOnly(
	hudsc *server.HeadsUpServerController,
	tscm *controllers.TiltServerControllerManager,
	cb *controllers.ControllerBuilder,
	ts *hud.TerminalStream,
) []store.Subscriber

Subscribers that only read from the new Tilt API, and run the API server.

func SpanIDForBuildLog

func SpanIDForBuildLog(buildCount int) logstore.SpanID

Types

type BuildController

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

func NewBuildController

func NewBuildController(b buildcontrol.BuildAndDeployer) *BuildController

func (*BuildController) DisableForTesting

func (c *BuildController) DisableForTesting()

func (*BuildController) OnChange

func (c *BuildController) OnChange(ctx context.Context, st store.RStore, summary store.ChangeSummary) error

type BuildOrder

type BuildOrder []buildcontrol.BuildAndDeployer

func DefaultBuildOrder

func DefaultBuildOrder(ibad *buildcontrol.ImageBuildAndDeployer, dcbad *buildcontrol.DockerComposeBuildAndDeployer,
	ltbad *buildcontrol.LocalTargetBuildAndDeployer, updMode liveupdates.UpdateMode) BuildOrder

func (BuildOrder) String

func (bo BuildOrder) String() string

type CompositeBuildAndDeployer

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

CompositeBuildAndDeployer tries to run each builder in order. If a builder emits an error, it uses the FallbackTester to determine whether the error is critical enough to stop the whole pipeline, or to fallback to the next builder.

func NewCompositeBuildAndDeployer

func NewCompositeBuildAndDeployer(builders BuildOrder, tracer trace.Tracer) *CompositeBuildAndDeployer

func (*CompositeBuildAndDeployer) BuildAndDeploy

func (composite *CompositeBuildAndDeployer) BuildAndDeploy(ctx context.Context, st store.RStore, specs []model.TargetSpec, currentState store.BuildStateSet) (store.BuildResultSet, error)

type FallbackTester

type FallbackTester func(error) bool

type HudStoppedAction

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

func NewHudStoppedAction

func NewHudStoppedAction(err error) HudStoppedAction

func (HudStoppedAction) Action

func (HudStoppedAction) Action()

type InitAction

type InitAction struct {
	TiltfilePath string
	ConfigFiles  []string
	UserArgs     []string

	TiltBuild model.TiltBuild
	StartTime time.Time

	AnalyticsUserOpt analytics.Opt

	CloudAddress string
	Token        token.Token
	TerminalMode store.TerminalMode
}

func (InitAction) Action

func (InitAction) Action()

type ManifestReloadedAction

type ManifestReloadedAction struct {
	OldManifest model.Manifest
	NewManifest model.Manifest
	Error       error
}

func (ManifestReloadedAction) Action

func (ManifestReloadedAction) Action()

type PodWatcherMaker

type PodWatcherMaker func(context.Context, *store.Store) error

type ServiceWatcherMaker

type ServiceWatcherMaker func(context.Context, *store.Store) error

type TelemetryScriptRanAction

type TelemetryScriptRanAction struct {
	At time.Time
}

func (TelemetryScriptRanAction) Action

func (TelemetryScriptRanAction) Action()

type UIDUpdateAction

type UIDUpdateAction struct {
	UID          types.UID
	EventType    watch.EventType
	ManifestName model.ManifestName
	Entity       k8s.K8sEntity
}

func (UIDUpdateAction) Action

func (UIDUpdateAction) Action()

type Upper

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

TODO(nick): maybe this should be called 'BuildEngine' or something? Upper seems like a poor and undescriptive name.

func NewUpper

func NewUpper(ctx context.Context, st *store.Store, subs []store.Subscriber) (Upper, error)

func (Upper) Dispatch

func (u Upper) Dispatch(action store.Action)

func (Upper) Init

func (u Upper) Init(ctx context.Context, action InitAction) error

func (Upper) Start

func (u Upper) Start(
	ctx context.Context,
	args []string,
	b model.TiltBuild,
	fileName string,
	initTerminalMode store.TerminalMode,
	analyticsUserOpt analytics.Opt,
	token token.Token,
	cloudAddress string,
) error