events

Documentation

Index

• Constants
• type CloudEvent
  • func NewCloudEventWithDefaults(eventType string) CloudEvent
  • func (e *CloudEvent) DefaultTopic() string
  • func (e *CloudEvent) ExtractSpan() (opentracing.SpanContext, error)
  • func (e *CloudEvent) InjectSpan(span opentracing.Span) error
• type CloudEventExtensions
  • func (ex CloudEventExtensions) ForeachKey(handler func(key, val string) error) error
  • func (ex CloudEventExtensions) Set(key, val string)
• type Handler
• type StreamParser
• type Subscription
• type Transport
• type Validator

Constants

const (
	// CloudEventsVersion defines version of CloudEvent specification used in Dispatch
	CloudEventsVersion = "0.1"
)

Types

type CloudEvent

type CloudEvent struct {
	// Mandatory, e.g. "user.created"
	EventType string `json:"eventType" validate:"required,max=128,eventtype"`
	// Optional, e.g. "VMODL6.5"
	EventTypeVersion string `json:"eventTypeVersion,omitempty" validate:"omitempty,min=1"`
	// Mandatory, fixed to "0.1"
	CloudEventsVersion string `json:"cloudEventsVersion" validate:"eq=0.1"`
	// Mandatory, e.g. "vcenter1.corp.local"
	Source string `json:"source" validate:"required"`
	// Mandatory, e.g. UUID or "43252363". Must be unique for this Source
	EventID string `json:"eventID" validate:"required"`
	// Optional, Timestamp in RFC 3339 format, e.g. "1985-04-12T23:20:50.52Z"
	EventTime time.Time `json:"eventTime,omitempty" validate:"-"`
	// Optional, if specified must be a valid URI
	SchemaURL string `json:"schemaURL,omitempty" validate:"omitempty,uri"`
	// Optional, if specified must be a valid mime type, e.g. "application/json"
	ContentType string `json:"contentType,omitempty" validate:"omitempty,min=1"`
	// Optional, key-value dictionary for use by Dispatch
	Extensions CloudEventExtensions `json:"extensions,omitempty" validate:"omitempty,min=1"`

	// Event payload
	Data json.RawMessage `json:"data" validate:"omitempty"`
}

CloudEvent structure implements CloudEvent spec: https://github.com/cloudevents/spec/blob/b0124528486d3f6b9a247cadd68d91b44b3d3ef4/spec.md

func NewCloudEventWithDefaults

func NewCloudEventWithDefaults(eventType string) CloudEvent

NewCloudEventWithDefaults creates new copy of CloudEvent struct, using reasonable defaults for all mandatory attributes, requiring only eventType to be explicitly specified.

func (*CloudEvent) DefaultTopic

func (e *CloudEvent) DefaultTopic() string

DefaultTopic returns a default representation of topic for messaging purposes.

func (*CloudEvent) ExtractSpan

func (e *CloudEvent) ExtractSpan() (opentracing.SpanContext, error)

ExtractSpan extracts OpenTracing Span from a CloudEvent.

func (*CloudEvent) InjectSpan

func (e *CloudEvent) InjectSpan(span opentracing.Span) error

InjectSpan injects OpenTracing Span into a CloudEvent.

type CloudEventExtensions

type CloudEventExtensions map[string]interface{}

CloudEventExtensions holds attributes for CloudEvent that are not part of the standard.

func (CloudEventExtensions) ForeachKey

func (ex CloudEventExtensions) ForeachKey(handler func(key, val string) error) error

ForeachKey conforms to the opentracing TextMapReader interface.

func (CloudEventExtensions) Set

func (ex CloudEventExtensions) Set(key, val string)

Set implements Set() of opentracing.TextMapWriter.

type Handler

type Handler func(context.Context, *CloudEvent)

Handler is a callback function used to handle received event

type StreamParser

type StreamParser interface {
	Parse(io.Reader) ([]CloudEvent, error)
}

StreamParser takes io.Reader and returns slice of CloudEvents. It is up to the implementation whether incorrect CloudEvent should be omitted from slice, or error should be returned. If error is returned, events slice is expected to be nil.

type Subscription

type Subscription interface {
	GetTopic() string
	Unsubscribe() error
	GetOrganization() string
}

Subscription represents an active subscription within Transport. Subscription can be stopped by calling Unsubscribe()

type Transport

type Transport interface {

	// Publish publishes the event using the underlying transport
	Publish(ctx context.Context, event *CloudEvent, topic string, organization string) error

	// Subscribe takes a handler to run on every event received on topic. Returns a cancelable Subscription
	Subscribe(ctx context.Context, topic string, organization string, handler Handler) (Subscription, error)
	Close()
}

Transport is an abstraction over possible implementation of messaging

type Validator

type Validator interface {
	Validate(event *CloudEvent) error
}

Validator takes a CloudEvent and validates it. Although CloudEvent struct includes tags following go-playground/validator convention, validation schema is up to the implementation.