Documentation ¶
Overview ¶
Package wsclient wraps the generated aws-sdk-go client to provide marshalling and unmarshalling of data over a websocket connection in the format expected by backend. It allows for bidirectional communication and acts as both a client-and-server in terms of requests, but only as a client in terms of connecting.
Package wsclient wraps the generated aws-sdk-go client to provide marshalling and unmarshalling of data over a websocket connection in the format expected by backend. It allows for bidirectional communication and acts as both a client-and-server in terms of requests, but only as a client in terms of connecting.
Index ¶
- Constants
- func DecodeConnectionError(data []byte, dec TypeDecoder) (interface{}, string, error)
- func DecodeData(data []byte, dec TypeDecoder) (interface{}, string, error)
- type ClientServer
- type ClientServerImpl
- func (cs *ClientServerImpl) AddRequestHandler(f RequestHandler)
- func (cs *ClientServerImpl) Connect() error
- func (cs *ClientServerImpl) ConsumeMessages() error
- func (cs *ClientServerImpl) CreateRequestMessage(input interface{}) ([]byte, error)
- func (cs *ClientServerImpl) Disconnect(...interface{}) error
- func (cs *ClientServerImpl) IsReady() bool
- func (cs *ClientServerImpl) MakeRequest(input interface{}) error
- func (cs *ClientServerImpl) SetAnyRequestHandler(f RequestHandler)
- func (cs *ClientServerImpl) SetConnection(conn wsconn.WebsocketConn)
- func (cs *ClientServerImpl) SetReadDeadline(t time.Time) error
- func (cs *ClientServerImpl) WriteMessage(send []byte) error
- type MakeRequestHookFunc
- type NotMarshallableWSRequest
- type ReceivedMessage
- type RequestHandler
- type RequestMessage
- type ServiceError
- type TypeDecoder
- type TypeDecoderImpl
- type UndecodableMessage
- type UnrecognizedWSRequestType
- type WSError
- type WSUnretriableErrors
Constants ¶
const ( // ServiceName defines the service name for the agent. This is used to sign messages // that are sent to the backend. ServiceName = "ecs" )
Variables ¶
This section is empty.
Functions ¶
func DecodeConnectionError ¶
func DecodeConnectionError(data []byte, dec TypeDecoder) (interface{}, string, error)
DecodeConnectionError decodes some of the connection errors returned by the backend. Some differ from the usual ones in that they do not have a 'type' and 'message' field, but rather are of the form {"ErrorType":"ErrorMessage"}
func DecodeData ¶
func DecodeData(data []byte, dec TypeDecoder) (interface{}, string, error)
DecodeData decodes a raw message into its type. E.g. An ACS message of the form {"type":"FooMessage","message":{"foo":1}} will be decoded into the corresponding *ecsacs.FooMessage type. The type string, "FooMessage", will also be returned as a convenience.
Types ¶
type ClientServer ¶
type ClientServer interface { AddRequestHandler(RequestHandler) // SetAnyRequestHandler takes a function with the signature 'func(i // interface{})' and calls it with every message the server passes down. // Only a single 'AnyRequestHandler' will be active at a given time for a // ClientServer SetAnyRequestHandler(RequestHandler) MakeRequest(input interface{}) error WriteMessage(input []byte) error Connect() error IsConnected() bool SetConnection(conn wsconn.WebsocketConn) Disconnect(...interface{}) error Serve() error SetReadDeadline(t time.Time) error io.Closer }
ClientServer is a combined client and server for the backend websocket connection
type ClientServerImpl ¶
type ClientServerImpl struct { // AgentConfig is the user-specified runtime configuration AgentConfig *config.Config // CredentialProvider is used to retrieve AWS credentials CredentialProvider *credentials.Credentials // RequestHandlers is a map from message types to handler functions of the // form: // "FooMessage": func(message *ecsacs.FooMessage) RequestHandlers map[string]RequestHandler // AnyRequestHandler is a request handler that, if set, is called on every // message with said message. It will be called before a RequestHandler is // called. It must take a single interface{} argument. AnyRequestHandler RequestHandler // MakeRequestHook is an optional callback that, if set, is called on every // generated request with the raw request body. MakeRequestHook MakeRequestHookFunc // URL is the full url to the backend, including path, querystring, and so on. URL string // RWTimeout is the duration used for setting read and write deadlines // for the websocket connection RWTimeout time.Duration ClientServer ServiceError TypeDecoder // contains filtered or unexported fields }
ClientServerImpl wraps commonly used methods defined in ClientServer interface.
func (*ClientServerImpl) AddRequestHandler ¶
func (cs *ClientServerImpl) AddRequestHandler(f RequestHandler)
AddRequestHandler adds a request handler to this client. A request handler *must* be a function taking a single argument, and that argument *must* be a pointer to a recognized 'ecsacs' struct. E.g. if you desired to handle messages from acs of type 'FooMessage', you would pass the following handler in:
func(message *ecsacs.FooMessage)
This function will panic if the passed in function does not have one pointer argument or the argument is not a recognized type. Additionally, the request handler will block processing of further messages on this connection so it's important that it return quickly.
func (*ClientServerImpl) Connect ¶
func (cs *ClientServerImpl) Connect() error
Connect opens a connection to the backend and upgrades it to a websocket. Calls to 'MakeRequest' can be made after calling this, but responses will not be receivable until 'Serve' is also called.
func (*ClientServerImpl) ConsumeMessages ¶
func (cs *ClientServerImpl) ConsumeMessages() error
ConsumeMessages reads messages from the websocket connection and handles read messages from an active connection.
func (*ClientServerImpl) CreateRequestMessage ¶
func (cs *ClientServerImpl) CreateRequestMessage(input interface{}) ([]byte, error)
CreateRequestMessage creates the request json message using the given input. Note, the input *MUST* be a pointer to a valid backend type that this client recognises.
func (*ClientServerImpl) Disconnect ¶ added in v1.11.1
func (cs *ClientServerImpl) Disconnect(...interface{}) error
Disconnect disconnects the connection
func (*ClientServerImpl) IsReady ¶ added in v1.14.1
func (cs *ClientServerImpl) IsReady() bool
IsReady gives a boolean response that informs the caller if the websocket connection is fully established.
func (*ClientServerImpl) MakeRequest ¶
func (cs *ClientServerImpl) MakeRequest(input interface{}) error
MakeRequest makes a request using the given input. Note, the input *MUST* be a pointer to a valid backend type that this client recognises
func (*ClientServerImpl) SetAnyRequestHandler ¶ added in v1.3.1
func (cs *ClientServerImpl) SetAnyRequestHandler(f RequestHandler)
SetAnyRequestHandler passes a RequestHandler object into the client.
func (*ClientServerImpl) SetConnection ¶ added in v1.14.1
func (cs *ClientServerImpl) SetConnection(conn wsconn.WebsocketConn)
SetConnection passes a websocket connection object into the client. This is used only in testing and should be avoided in non-test code.
func (*ClientServerImpl) SetReadDeadline ¶ added in v1.14.5
func (cs *ClientServerImpl) SetReadDeadline(t time.Time) error
SetReadDeadline sets the read deadline for the websocket connection A read timeout results in an io error if there are any outstanding reads that exceed the deadline
func (*ClientServerImpl) WriteMessage ¶ added in v1.14.1
func (cs *ClientServerImpl) WriteMessage(send []byte) error
WriteMessage wraps the low level websocket write method with a lock
type MakeRequestHookFunc ¶
MakeRequestHookFunc is a function that is invoked on every generated request with the raw request body. MakeRequestHookFunc must return either the body to send or an error.
type NotMarshallableWSRequest ¶
NotMarshallableWSRequest represents that the given request input could not be marshalled
func (*NotMarshallableWSRequest) Error ¶
func (u *NotMarshallableWSRequest) Error() string
Error implements error
func (*NotMarshallableWSRequest) Retry ¶
func (u *NotMarshallableWSRequest) Retry() bool
Retry implements Retriable
type ReceivedMessage ¶
type ReceivedMessage struct { Type string `json:"type"` Message json.RawMessage `json:"message"` }
ReceivedMessage is the intermediate message used to unmarshal a message from backend
type RequestHandler ¶
type RequestHandler interface{}
RequestHandler would be func(*ecsacs.T for T in ecsacs.*) to be more proper, but it needs to be interface{} to properly capture that
type RequestMessage ¶
type RequestMessage struct { Type string `json:"type"` Message json.RawMessage `json:"message"` }
RequestMessage is the intermediate message marshalled to send to backend.
type ServiceError ¶
type ServiceError interface {
NewError(err interface{}) *WSError
}
ServiceError defines methods to return new backend specific error objects.
type TypeDecoder ¶
type TypeDecoder interface { // NewOfType returns an object of a recognized type for a given type name. // It additionally returns a boolean value which is set to false for an // unrecognized type. NewOfType(string) (interface{}, bool) // GetRecognizedTypes returns a map of type-strings (as passed in acs/tcs messages as // the 'type' field) to a pointer to the corresponding struct type this type should // be marshalled/unmarshalled to/from. GetRecognizedTypes() map[string]reflect.Type }
TypeDecoder interface defines methods to decode ecs types.
func BuildTypeDecoder ¶ added in v1.14.1
func BuildTypeDecoder(recognizedTypes []interface{}) TypeDecoder
BuildTypeDecoder takes a list of interfaces and stores them internally as a list of typeMappings in the format below. "MyMessage": TypeOf(ecstcs.MyMessage)
type TypeDecoderImpl ¶ added in v1.14.1
type TypeDecoderImpl struct {
// contains filtered or unexported fields
}
TypeDecoderImpl is an implementation for general use between ACS and TCS clients
func (*TypeDecoderImpl) GetRecognizedTypes ¶ added in v1.14.1
func (d *TypeDecoderImpl) GetRecognizedTypes() map[string]reflect.Type
func (*TypeDecoderImpl) NewOfType ¶ added in v1.14.1
func (d *TypeDecoderImpl) NewOfType(typeString string) (interface{}, bool)
type UndecodableMessage ¶
type UndecodableMessage struct {
Msg string
}
UndecodableMessage indicates that a message from the backend could not be decoded
func (*UndecodableMessage) Error ¶
func (u *UndecodableMessage) Error() string
type UnrecognizedWSRequestType ¶
type UnrecognizedWSRequestType struct {
Type string
}
UnrecognizedWSRequestType specifies that a given type is not recognized. This error is not retriable.
func (*UnrecognizedWSRequestType) Error ¶
func (u *UnrecognizedWSRequestType) Error() string
Error implements error
func (*UnrecognizedWSRequestType) Retry ¶
func (u *UnrecognizedWSRequestType) Retry() bool
Retry implements Retriable
type WSError ¶
type WSError struct { ErrObj interface{} Type string WSUnretriableErrors }
WSError wraps all the typed errors that the backend may return This will not be needed once the aws-sdk-go generation handles error types more cleanly
type WSUnretriableErrors ¶
type WSUnretriableErrors interface {
Get() []interface{}
}
WSUnretriableErrors defines methods to retrieve the list of unretriable errors.