SSH

Rust SDK - SSH API reference

Reach a running sandbox over SSH: open a native in-process SSH client, run exec requests, attach an interactive shell, transfer files over SFTP, or stand up a reusable SSH server endpoint. Requires the ssh feature. See SSH for usage flows.

microsandbox = { version = "0.5.8", features = ["ssh"] }

Sandbox

sb.ssh()

fn ssh(&self) -> SandboxSshOps

Example

let client = sb.ssh().connect().await?;

Return the SSH namespace for this sandbox. The namespace holds the SSH client and server helpers; nothing connects until you call connect or server.

Returns

SandboxSshOps

SSH namespace for this sandbox.

SandboxSshOps

Returned by sb.ssh()

SSH operations for a sandbox.

ssh.connect()

async fn connect(&self) -> MicrosandboxResult<SshClient>

Example

let client = sb.ssh().connect().await?;
let out = client.exec("uname -a").await?;

Connect a native in-process SSH client to this sandbox. Generates an ephemeral Ed25519 client and host key pair, stands up an internal server bound to a duplex stream, and authenticates over public key. Uses default client options (user root, terminal from $TERM, SFTP enabled).

Returns

SshClient

Connected SSH client session.

ssh.open_client()

async fn open_client(&self) -> MicrosandboxResult<SshClient>

Alias for connect.

Returns

SshClient

Connected SSH client session.

ssh.connect_with()

async fn connect_with(
    &self,
    f: impl FnOnce(SshClientOptionsBuilder) -> SshClientOptionsBuilder,
) -> MicrosandboxResult<SshClient>

Example

let client = sb.ssh().connect_with(|opts| opts
    .user("app")
    .term("xterm-256color")).await?;

Connect a native in-process SSH client with custom options. The closure configures the login user, terminal name, whether SFTP is enabled on the internal server, and the SSH inactivity timeout.

Parameters

fFnOnce(SshClientOptionsBuilder)

Configure user, terminal, SFTP support, and the inactivity timeout.

Returns

SshClient

Connected SSH client session.

ssh.open_client_with()

async fn open_client_with(
    &self,
    f: impl FnOnce(SshClientOptionsBuilder) -> SshClientOptionsBuilder,
) -> MicrosandboxResult<SshClient>

Alias for connect_with.

Parameters

fFnOnce(SshClientOptionsBuilder)

Configure user, terminal, SFTP support, and the inactivity timeout.

Returns

SshClient

Connected SSH client session.

ssh.server()

Local-only

async fn server(&self) -> MicrosandboxResult<SshServer>

Example

let server = sb.ssh().server().await?;
let (client_io, server_io) = tokio::io::duplex(64 * 1024);
server.serve(server_io).await?;

Prepare a reusable SSH server endpoint for this sandbox. Loads or creates the host key and resolves authorized keys from the default authorized-keys file. The returned SshServer is cloneable and can serve many connections.

Returns

SshServer

Reusable SSH server endpoint.

ssh.prepare_server()

Local-only

async fn prepare_server(&self) -> MicrosandboxResult<SshServer>

Alias for server.

Returns

SshServer

Reusable SSH server endpoint.

ssh.server_with()

Limited on cloud

async fn server_with(
    &self,
    f: impl FnOnce(SshServerOptionsBuilder) -> SshServerOptionsBuilder,
) -> MicrosandboxResult<SshServer>

Example

let server = sb.ssh().server_with(|opts| opts
    .authorized_key("ssh-ed25519 AAAAC3Nza...")
    .user("app")
    .sftp(false)).await?;

Prepare a server endpoint with custom host-key, authorization, guest-user, SFTP, or inactivity-timeout options. If no authorized keys are configured, the default authorized-keys file is loaded; an empty key set is an error.

Parameters

fFnOnce(SshServerOptionsBuilder)

Configure host key, authorized keys, guest user, SFTP, and the inactivity timeout.

Returns

SshServer

Reusable SSH server endpoint.

ssh.prepare_server_with()

Limited on cloud

async fn prepare_server_with(
    &self,
    f: impl FnOnce(SshServerOptionsBuilder) -> SshServerOptionsBuilder,
) -> MicrosandboxResult<SshServer>

Alias for server_with.

Parameters

fFnOnce(SshServerOptionsBuilder)

Configure host key, authorized keys, guest user, and SFTP.

Returns

SshServer

Reusable SSH server endpoint.

SshClient

Returned by ssh.connect(), ssh.connect_with()

Native in-process SSH client session.

client.exec()

async fn exec(&self, command: impl Into<String>) -> MicrosandboxResult<SshOutput>

Example

let out = client.exec("echo hello").await?;
println!("exit {}: {}", out.status, String::from_utf8_lossy(&out.stdout));

Run an SSH exec request and collect stdout, stderr, and the exit status. The command is run through the sandbox’s configured shell (default /bin/sh -c). No PTY is requested.

Parameters

commandimpl Into<String>

Command string sent through SSH.

Returns

SshOutput

Captured output and exit status.

client.exec_with()

async fn exec_with(
    &self,
    command: impl Into<String>,
    f: impl FnOnce(SshExecOptionsBuilder) -> SshExecOptionsBuilder,
) -> MicrosandboxResult<SshOutput>

Example

let out = client.exec_with("top -bn1", |opts| opts.tty(true)).await?;

Run an SSH exec request with options. The closure can request a PTY via tty; when a PTY is allocated, stderr is folded into stdout.

Parameters

commandimpl Into<String>

Command string sent through SSH.

fFnOnce(SshExecOptionsBuilder)

Configure exec options.

Returns

SshOutput

Captured output and exit status.

client.attach()

async fn attach(&self) -> MicrosandboxResult<i32>

Example

let code = client.attach().await?;
println!("shell exited with {code}");

Attach the local terminal to an interactive SSH shell. Requests a PTY sized to the current terminal, puts the terminal into raw mode, forwards keystrokes, relays window-resize events, and returns when the shell exits or the default detach key sequence is typed.

Returns

i32

Shell exit code (128 if terminated by signal).

client.attach_with()

async fn attach_with(
    &self,
    f: impl FnOnce(SshAttachOptionsBuilder) -> SshAttachOptionsBuilder,
) -> MicrosandboxResult<i32>

Example

let code = client.attach_with(|opts| opts
    .term("xterm-256color")
    .detach_keys("ctrl-p,ctrl-q")).await?;

Attach an interactive shell with custom terminal and detach-key options.

Parameters

fFnOnce(SshAttachOptionsBuilder)

Configure terminal name and detach keys.

Returns

i32

Shell exit code (128 if terminated by signal).

client.sftp()

async fn sftp(&self) -> MicrosandboxResult<SftpClient>

Example

let sftp = client.sftp().await?;
let mut file = sftp.create("/tmp/hello.txt").await?;

Open an SFTP client session over this SSH connection. Requests the sftp subsystem and returns a high-level SFTP session for reading, writing, and listing files inside the guest.

Returns

SftpClient

SFTP client session.

client.close()

async fn close(self) -> MicrosandboxResult<()>

Example

client.close().await?;

Close this native SSH client session. Sends a disconnect and aborts the internal server task. Consumes the client.

SshServer

Returned by ssh.server(), ssh.server_with()

Reusable SSH server endpoint for a sandbox.

server.serve()

async fn serve<S>(&self, stream: S) -> MicrosandboxResult<()>
where
    S: AsyncRead + AsyncWrite + Unpin + Send + 'static,

Example

let server = sb.ssh().server().await?;
let (client_io, server_io) = tokio::io::duplex(64 * 1024);
tokio::spawn(async move { server.serve(server_io).await });

Serve one SSH connection over an ordered duplex stream. Runs the SSH handshake and session loop to completion. Returns when the connection closes.

Parameters

streamS: AsyncRead + AsyncWrite

Ordered duplex SSH transport.

server.serve_connection()

async fn serve_connection<S>(&self, stream: S) -> MicrosandboxResult<()>
where
    S: AsyncRead + AsyncWrite + Unpin + Send + 'static,

Alias for serve.

Parameters

streamS: AsyncRead + AsyncWrite

Ordered duplex SSH transport.

SshStdioStream

Used by server.serve()

Ordered duplex stream backed by this process’s stdin and stdout. Implements AsyncRead and AsyncWrite.

SshStdioStream::new()

fn new() -> Self

Example

use microsandbox::SshStdioStream;

let server = sb.ssh().server().await?;
server.serve(SshStdioStream::new()).await?;

Create a stdio SSH transport stream backed by this process’s stdin and stdout. Implements AsyncRead and AsyncWrite, so it can be passed straight to serve to bridge an SSH connection over the parent process’s standard streams. Also available via Default.

Returns

SshStdioStream

Duplex stream over stdin/stdout.

Constants

DEFAULT_SSH_HOST

pub const DEFAULT_SSH_HOST: &str = "127.0.0.1";

Default SSH listener host used by the CLI adapter when binding a sandbox SSH endpoint.

DEFAULT_SSH_PORT

pub const DEFAULT_SSH_PORT: u16 = 2222;

Default SSH listener port used by the CLI adapter when binding a sandbox SSH endpoint.

SshClientOptionsBuilder

Used by ssh.connect_with()

Builder for SSH client options. Defaults: user root, terminal from $TERM (falling back to xterm), SFTP enabled, and the global SSH inactivity timeout.

client_options.user()

user()

SSH login user. Default root.

client_options.term()

term()

Terminal name for interactive sessions.

client_options.sftp()

sftp()

Enable or disable SFTP on the internal server. Default true.

client_options.inactivity_timeout()

inactivity_timeout(timeout: Duration)

Override the internal server inactivity timeout. Duration::ZERO disables it.

client_options.disable_inactivity_timeout()

disable_inactivity_timeout()

Disable the internal server inactivity timeout.

client_options.build()

build()

Finalize the options.

SshExecOptionsBuilder

Used by client.exec_with()

Builder for SSH exec options.

exec_options.tty()

tty()

Request a PTY for the exec channel. Default false.

exec_options.build()

build()

Finalize the options.

SshAttachOptionsBuilder

Used by client.attach_with()

Builder for interactive SSH attach options. Default terminal comes from $TERM (falling back to xterm); detach keys default to the standard sequence.

attach_options.term()

term()

Terminal name for the shell.

attach_options.detach_keys()

detach_keys()

Detach key sequence.

attach_options.build()

build()

Finalize the options.

SshServerOptionsBuilder

Used by ssh.server_with()

Builder for SSH server options. SFTP is enabled by default; the inactivity timeout inherits the global SSH setting; when no authorized keys are provided, the default authorized-keys file is loaded.

server_options.host_key_path()

host_key_path()

Override the host private key path.

server_options.host_key()

host_key()

Use an in-memory host private key.

server_options.authorized_keys_path()

authorized_keys_path()

Override the authorized-keys path.

server_options.authorized_key()

authorized_key()

Add one in-memory authorized public key.

server_options.user()

user()

Override the guest user used for exec requests.

server_options.sftp()

sftp()

Enable or disable SFTP. Default true.

server_options.inactivity_timeout()

inactivity_timeout(timeout: Duration)

Override the SSH inactivity timeout. Duration::ZERO disables it.

server_options.disable_inactivity_timeout()

disable_inactivity_timeout()

Disable the SSH inactivity timeout.

server_options.build()

build()

Finalize the options.

SftpClient

Returned by client.sftp()

High-level SFTP client session.

pub type SftpClient = russh_sftp::client::SftpSession;

Types

SshOutput

Returned by client.exec(), client.exec_with()

Output from an SSH exec request.

Field	Type	Description
status	i32	Exit status code.
stdout	Bytes	Captured stdout bytes.
stderr	Bytes	Captured stderr bytes (folded into stdout when a PTY is allocated).