butler

Documentation

Overview

Package butler is the main engine for the Butler executable. It is an internal package to support github.com/luci/luci-go/logdog/client/cmd/logdog_butler.

Index

• Constants
• type Butler
  • func New(ctx context.Context, config Config) (*Butler, error)
  • func (b *Butler) Activate()
  • func (b *Butler) AddStream(rc io.ReadCloser, p *streamproto.Properties) error
  • func (b *Butler) AddStreamServer(streamServer streamserver.StreamServer)
  • func (b *Butler) Streams() []types.StreamName
  • func (b *Butler) Wait() error
• type Config
  • func (c *Config) Validate() error

Constants

const (
	// DefaultMaxBufferAge is the default amount of time that a log entry may
	// be buffered before being dispatched.
	DefaultMaxBufferAge = time.Duration(5 * time.Second)

	// DefaultOutputWorkers is the default number of output workers to use.
	DefaultOutputWorkers = 16
)

Types

type Butler

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

Butler is the Butler application structure. The Butler runs until closed. During operation, it acts as a service manager and data router, routing: - Messages from Streams to the attached Output. - Streams from a StreamServer to the Stream list (AddStream).

func New

func New(ctx context.Context, config Config) (*Butler, error)

New instantiates a new Butler instance and starts its processing.

func (*Butler) Activate

func (b *Butler) Activate()

Activate notifies the Butler that its current stream load is sufficient. This enables it to exit Run when it reaches a stream count of zero. Prior to activation, the Butler would block in Run regardless of stream count.

func (*Butler) AddStream

func (b *Butler) AddStream(rc io.ReadCloser, p *streamproto.Properties) error

AddStream adds a Stream to the Butler. This is goroutine-safe.

If no error is returned, the Butler assumes ownership of the supplied stream. The stream will be closed when processing is finished.

If an error is occurred, the caller is still the owner of the stream and is responsible for closing it.

func (*Butler) AddStreamServer

func (b *Butler) AddStreamServer(streamServer streamserver.StreamServer)

AddStreamServer adds a StreamServer to the Butler. This is goroutine-safe and may be called anytime before or during Butler execution.

After this call completes, the Butler assumes ownership of the StreamServer.

func (*Butler) Streams

func (b *Butler) Streams() []types.StreamName

Streams returns a sorted list of stream names that have been registered to the Butler.

func (*Butler) Wait

func (b *Butler) Wait() error

Wait blocks until the Butler instance has completed, returning with the Butler's return code.

type Config

type Config struct {
	// Output is the output instance to use for log dispatch.
	Output output.Output
	// OutputWorkers is the number of simultaneous goroutines that will be used
	// to output Butler log data. If zero, DefaultOutputWorkers will be used.
	OutputWorkers int

	// Project is the project that the log stream will be bound to.
	Project cfgtypes.ProjectName
	// Prefix is the log stream common prefix value.
	Prefix types.StreamName

	// GlobalTags are a set of global log stream tags to apply to individual
	// streams on registration. Individual stream tags will override tags with
	// the same key.
	GlobalTags streamproto.TagMap

	// BufferLogs, if true, instructs the butler to buffer collected log data
	// before sending it to Output.
	BufferLogs bool
	// If buffering logs, this is the maximum amount of time that a log will
	// be buffered before being marked for dispatch. If this is zero,
	// DefaultMaxBufferAge will be used.
	MaxBufferAge time.Duration

	// TeeStdout, if not nil, is the Writer that will be used for streams
	// requesting STDOUT tee.
	TeeStdout io.Writer
	// TeeStderr, if not nil, is the Writer that will be used for streams
	// requesting STDERR tee.
	TeeStderr io.Writer

	// IOKeepAliveInterval configures the Butler to perform I/O pings.
	//
	// The Butler will monitor I/O events on all of its subordinate streams. If
	// a stream receives I/O, and no streams marked "IOKeepAlive" have written
	// I/O in this period, an I/O keep-alive event will be written to all
	// "IOKeepAlive" streams.
	IOKeepAliveInterval time.Duration
	// IOKeepAliveWriter is an io.Writer to send keep-alive updates through. This
	// must be set for I/O keep-alive to be active.
	IOKeepAliveWriter io.Writer
}

Config is the set of Butler configuration parameters.

func (*Config) Validate

func (c *Config) Validate() error

Validate validates that the configuration is sufficient to instantiate a Butler instance.