This library implements a backend that connects to a Docker socket and launches a new container for each connection, then runs executes a separate command per channel using docker exec. It replaces the legacy dockerrun backend.
⚠⚠⚠ Warning: This is a developer documentation. ⚠⚠⚠
The user documentation for ContainerSSH is located at containerssh.io.
This library implements a NetworkConnectionHandler from the sshserver library. This can be embedded into a connection handler.
The network connection handler can be created with the New() method:
var client net.TCPAddr
connectionID := "0123456789ABCDEF"
config := docker.Config{
//...
}
collector := metrics.New()
dr, err := docker.New(
client,
connectionID,
config,
logger,
collector.MustCreateCounter("backend_requests", "", ""),
collector.MustCreateCounter("backend_failures", "", ""),
)
if err != nil {
// Handle error
}The logger parameter is a logger from the ContainerSSH logger library.
The dr variable can then be used to create a container on finished handshake:
ssh, err := dr.OnHandshakeSuccess("provided-connection-username")Conversely, on disconnect you must call dr.OnDisconnect(). The ssh variable can then be used to create session channels:
var channelID uint64 = 0
extraData := []byte{}
session, err := ssh.OnSessionChannel(channelID, extraData)Finally, the session can be used to launch programs:
var requestID uint64 = 0
err = session.OnEnvRequest(requestID, "foo", "bar")
// ...
requestID = 1
var stdin io.Reader
var stdout, stderr io.Writer
err = session.OnShell(
requestID,
stdin,
stdout,
stderr,
func(exitStatus ExitStatus) {
// ...
},
)This library supports several operating modes:
connectioncreates a container per connection and uses thedocker execmechanism to launch SSH programs inside the container. This mode ignores theCMDof the container image and uses theidleProgramsetting to launch inside the container.sessioncreates a container per session and potentially results in multiple containers for a single SSH connection. This mode uses theCMDof the container image or from the configuration.