distribution/notifications/event.go
Stephen J Day 26b7fe4a91 Use "Size" field to describe blobs over "Length"
After consideration, we've changed the main descriptor field name to for number
of bytes to "size" to match convention. While this may be a subjective
argument, commonly we refer to files by their "size" rather than their
"length". This will match other conventions, like `(FileInfo).Size()` and
methods on `io.SizeReaderAt`. Under more broad analysis, this argument doesn't
necessarily hold up. If anything, "size" is shorter than "length".

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2015-07-17 17:07:11 -07:00

152 lines
5.3 KiB
Go

package notifications
import (
"fmt"
"time"
"github.com/docker/distribution"
)
// EventAction constants used in action field of Event.
const (
EventActionPull = "pull"
EventActionPush = "push"
EventActionDelete = "delete"
)
const (
// EventsMediaType is the mediatype for the json event envelope. If the
// Event, ActorRecord, SourceRecord or Envelope structs change, the version
// number should be incremented.
EventsMediaType = "application/vnd.docker.distribution.events.v1+json"
// LayerMediaType is the media type for image rootfs diffs (aka "layers")
// used by Docker. We don't expect this to change for quite a while.
layerMediaType = "application/vnd.docker.container.image.rootfs.diff+x-gtar"
)
// Envelope defines the fields of a json event envelope message that can hold
// one or more events.
type Envelope struct {
// Events make up the contents of the envelope. Events present in a single
// envelope are not necessarily related.
Events []Event `json:"events,omitempty"`
}
// TODO(stevvooe): The event type should be separate from the json format. It
// should be defined as an interface. Leaving as is for now since we don't
// need that at this time. If we make this change, the struct below would be
// called "EventRecord".
// Event provides the fields required to describe a registry event.
type Event struct {
// ID provides a unique identifier for the event.
ID string `json:"id,omitempty"`
// Timestamp is the time at which the event occurred.
Timestamp time.Time `json:"timestamp,omitempty"`
// Action indicates what action encompasses the provided event.
Action string `json:"action,omitempty"`
// Target uniquely describes the target of the event.
Target struct {
// TODO(stevvooe): Use http.DetectContentType for layers, maybe.
distribution.Descriptor
// Length in bytes of content. Same as Size field in Descriptor.
// Provided for backwards compatibility.
Length int64 `json:"length,omitempty"`
// Repository identifies the named repository.
Repository string `json:"repository,omitempty"`
// URL provides a direct link to the content.
URL string `json:"url,omitempty"`
} `json:"target,omitempty"`
// Request covers the request that generated the event.
Request RequestRecord `json:"request,omitempty"`
// Actor specifies the agent that initiated the event. For most
// situations, this could be from the authorizaton context of the request.
Actor ActorRecord `json:"actor,omitempty"`
// Source identifies the registry node that generated the event. Put
// differently, while the actor "initiates" the event, the source
// "generates" it.
Source SourceRecord `json:"source,omitempty"`
}
// ActorRecord specifies the agent that initiated the event. For most
// situations, this could be from the authorizaton context of the request.
// Data in this record can refer to both the initiating client and the
// generating request.
type ActorRecord struct {
// Name corresponds to the subject or username associated with the
// request context that generated the event.
Name string `json:"name,omitempty"`
// TODO(stevvooe): Look into setting a session cookie to get this
// without docker daemon.
// SessionID
// TODO(stevvooe): Push the "Docker-Command" header to replace cookie and
// get the actual command.
// Command
}
// RequestRecord covers the request that generated the event.
type RequestRecord struct {
// ID uniquely identifies the request that initiated the event.
ID string `json:"id"`
// Addr contains the ip or hostname and possibly port of the client
// connection that initiated the event. This is the RemoteAddr from
// the standard http request.
Addr string `json:"addr,omitempty"`
// Host is the externally accessible host name of the registry instance,
// as specified by the http host header on incoming requests.
Host string `json:"host,omitempty"`
// Method has the request method that generated the event.
Method string `json:"method"`
// UserAgent contains the user agent header of the request.
UserAgent string `json:"useragent"`
}
// SourceRecord identifies the registry node that generated the event. Put
// differently, while the actor "initiates" the event, the source "generates"
// it.
type SourceRecord struct {
// Addr contains the ip or hostname and the port of the registry node
// that generated the event. Generally, this will be resolved by
// os.Hostname() along with the running port.
Addr string `json:"addr,omitempty"`
// InstanceID identifies a running instance of an application. Changes
// after each restart.
InstanceID string `json:"instanceID,omitempty"`
}
var (
// ErrSinkClosed is returned if a write is issued to a sink that has been
// closed. If encountered, the error should be considered terminal and
// retries will not be successful.
ErrSinkClosed = fmt.Errorf("sink: closed")
)
// Sink accepts and sends events.
type Sink interface {
// Write writes one or more events to the sink. If no error is returned,
// the caller will assume that all events have been committed and will not
// try to send them again. If an error is received, the caller may retry
// sending the event. The caller should cede the slice of memory to the
// sink and not modify it after calling this method.
Write(events ...Event) error
// Close the sink, possibly waiting for pending events to flush.
Close() error
}