rclone/backend/sftp/ssh.go

74 lines
2.3 KiB
Go

//go:build !plan9
// +build !plan9
package sftp
import "io"
// Interfaces for ssh client and session implemented in ssh_internal.go and ssh_external.go
// An interface for an ssh client to abstract over internal ssh library and external binary
type sshClient interface {
// Wait blocks until the connection has shut down, and returns the
// error causing the shutdown.
Wait() error
// SendKeepAlive sends a keepalive message to keep the connection open
SendKeepAlive()
// Close the connection
Close() error
// NewSession opens a new sshSession for this sshClient. (A
// session is a remote execution of a program.)
NewSession() (sshSession, error)
// CanReuse indicates if this client can be reused
CanReuse() bool
}
// An interface for an ssh session to abstract over internal ssh library and external binary
type sshSession interface {
// Setenv sets an environment variable that will be applied to any
// command executed by Shell or Run.
Setenv(name, value string) error
// Start runs cmd on the remote host. Typically, the remote
// server passes cmd to the shell for interpretation.
// A Session only accepts one call to Run, Start or Shell.
Start(cmd string) error
// StdinPipe returns a pipe that will be connected to the
// remote command's standard input when the command starts.
StdinPipe() (io.WriteCloser, error)
// StdoutPipe returns a pipe that will be connected to the
// remote command's standard output when the command starts.
// There is a fixed amount of buffering that is shared between
// stdout and stderr streams. If the StdoutPipe reader is
// not serviced fast enough it may eventually cause the
// remote command to block.
StdoutPipe() (io.Reader, error)
// RequestSubsystem requests the association of a subsystem
// with the session on the remote host. A subsystem is a
// predefined command that runs in the background when the ssh
// session is initiated
RequestSubsystem(subsystem string) error
// Run runs cmd on the remote host. Typically, the remote
// server passes cmd to the shell for interpretation.
// A Session only accepts one call to Run, Start, Shell, Output,
// or CombinedOutput.
Run(cmd string) error
// Close the session
Close() error
// Set the stdout
SetStdout(io.Writer)
// Set the stderr
SetStderr(io.Writer)
}