Documentation
¶
Overview ¶
Package bootstrap is the exchange between `upterm host` and the daemon it spawns, over the connection the daemon inherits. The child reports and asks; the parent shows, answers and, once the command has started, leaves.
Index ¶
- Variables
- type Child
- func (c *Child) Claimed(m *api.Claimed) error
- func (c *Child) Close() error
- func (c *Child) Disarm()
- func (c *Child) Failed(msg string, nameInUse, abandoned bool)
- func (c *Child) Listening(socket string, hostKeys []string) error
- func (c *Child) Print(text string)
- func (c *Child) ReadSecret(prompt string) ([]byte, error)
- func (c *Child) Reader() io.Reader
- func (c *Child) SessionCreated(sess *api.GetSessionResponse) (api.Accept_Decision, error)
- func (c *Child) Started(sessionID, status string) error
- func (c *Child) Writer() io.Writer
- type Conn
- type Handlers
- type NoAnswerError
- type Outcome
- type Parent
Constants ¶
This section is empty.
Variables ¶
var ErrDaemonGone = errors.New("the session daemon exited before reporting whether it started")
ErrDaemonGone: the daemon closed the channel before saying whether it started. Its log says why.
var ErrParentGone = errors.New("the process that started this session went away")
ErrParentGone: the process that started this session closed its end of the channel, or never answered.
Functions ¶
This section is empty.
Types ¶
type Child ¶
type Child struct {
// contains filtered or unexported fields
}
Child is the daemon's half of the exchange.
One goroutine reads the parent's messages for the Child's life. Replies go to whoever is waiting for one; the protocol is strictly request/reply, so at most one is ever outstanding. A read error — the parent closing its end, or dying — while the Child is armed calls onParentGone, once: that is parent-lifetime cancellation, and Disarm is what ends it.
func NewChild ¶
func NewChild(rw io.ReadWriteCloser, onParentGone func()) *Child
NewChild starts reading rw. It is armed: the parent leaving is abandonment until Disarm is called.
func (*Child) Close ¶
Close disarms and closes the connection. Disarming first: the close makes the reader return, and a return after Disarm is not abandonment.
func (*Child) Disarm ¶
func (c *Child) Disarm()
Disarm stops treating the parent's departure as abandonment. Call it the instant the command has started, before Started: a parent that exits the moment it is told the session is up must not be read as leaving it.
func (*Child) Failed ¶
Failed reports that the session did not start. Nothing is sent after Started: the parent has gone by then, and a session that started and then ended is an outcome the record carries, not a startup failure.
func (*Child) Print ¶
Print sends text for the parent's stderr. Best-effort: a parent that is gone will be noticed by the next thing that needs an answer.
func (*Child) ReadSecret ¶
ReadSecret asks the parent's terminal for a line that must not echo.
func (*Child) SessionCreated ¶
func (c *Child) SessionCreated(sess *api.GetSessionResponse) (api.Accept_Decision, error)
SessionCreated is gate 1 and 2 in one round trip: the parent shows the session and answers with the operator's decision.
type Conn ¶
type Conn struct {
// contains filtered or unexported fields
}
Conn frames Startup messages over a byte stream, one varint-delimited protobuf per message. Send is safe for concurrent use; Recv is for one goroutine.
func NewConn ¶
func NewConn(rw io.ReadWriteCloser) *Conn
type Handlers ¶
type Handlers struct {
Claimed func(*api.Claimed)
SessionCreated func(*api.GetSessionResponse) api.Accept_Decision
Listening func(*api.Listening)
}
Handlers receives the child's reports. Each is called on Run's goroutine, between messages; SessionCreated blocks the exchange for as long as the operator takes, which is the point.
type NoAnswerError ¶
type NoAnswerError struct{ Reason string }
NoAnswerError: the parent could not answer a read, and says why — no terminal for a secret, EOF on its stdin. Callers that wrap it in their own message (the host-key callback does) keep the reason.
func (*NoAnswerError) Error ¶
func (e *NoAnswerError) Error() string
type Parent ¶
type Parent struct {
// contains filtered or unexported fields
}
Parent is `upterm host`'s half of the exchange.
Source Files