sshlife

Documentation

Overview

Package sshlife provides a thin SSH client used by xpc bootstrap and the agent-lifecycle subcommands. We deliberately use a minimal feature set:

Dial(addr, user, password)
Run(cmd) (stdout, stderr, exitStatus, err)
PutFile(localPath, remotePath) -- via `cat > <remote>` over stdin pipe
PutBytes(data, remotePath)     -- same, from an in-memory buffer

The remote shell is the Cygwin bash sshd that xpctl bootstraps on the VM. Paths are POSIX-style (/cygdrive/c/...) for the upload helpers; the PutFile/PutBytes wrappers convert from C:\... automatically.

Host-key trust uses TOFU (trust on first use): the first connection to a new host writes its key to ~/.xpc/known_hosts; subsequent connections require a byte-for-byte match. A changed key short-circuits the dial with an error.

Index

• func TOFUHostKey(path string) ssh.HostKeyCallback
• type Client
  • func Dial(addr string, opt DialOptions) (*Client, error)
  • func (c *Client) Close() error
  • func (c *Client) PutBytes(data []byte, remotePath string, timeout time.Duration) error
  • func (c *Client) PutFile(localPath, remotePath string, timeout time.Duration) error
  • func (c *Client) Run(cmd string, timeout time.Duration) (stdout, stderr string, exitStatus int, err error)
• type DialOptions

Functions

func TOFUHostKey

func TOFUHostKey(path string) ssh.HostKeyCallback

TOFUHostKey returns an ssh.HostKeyCallback that:

• accepts and records the host key on first contact (writes to path)
• rejects subsequent connections whose key differs from the recorded one

The known_hosts file uses the standard OpenSSH-ish line format "<host> <key-type> <base64-key>". Multiple entries per host are tolerated; the callback succeeds if any line matches the presented key exactly.

Types

type Client

type Client struct {
	// contains filtered or unexported fields
}

Client is a thin wrapper around an *ssh.Client that opens a fresh session for each Run/PutFile/PutBytes call.

func Dial

func Dial(addr string, opt DialOptions) (*Client, error)

Dial opens an SSH connection. addr is "host:port"; if no port, 22 is used.

func (*Client) Close

func (c *Client) Close() error

Close releases the SSH connection.

func (*Client) PutBytes

func (c *Client) PutBytes(data []byte, remotePath string, timeout time.Duration) error

PutBytes is PutFile from an in-memory byte slice.

func (*Client) PutFile

func (c *Client) PutFile(localPath, remotePath string, timeout time.Duration) error

PutFile uploads a local file to remotePath. remotePath is a Windows-style path (e.g. C:\xpc\agent.py); it's translated to /cygdrive/c/xpc/agent.py for the bash `cat > ...` invocation.

func (*Client) Run

func (c *Client) Run(cmd string, timeout time.Duration) (stdout, stderr string, exitStatus int, err error)

Run executes cmd in a remote shell, returning combined stdout, stderr, and the exit status. A non-zero exit status is returned in the int but does NOT produce an error; callers decide whether to treat it as failure.

type DialOptions

type DialOptions struct {
	User     string
	Password string
	Timeout  time.Duration
	// HostKeyCallback overrides the default TOFU callback. Leave nil to
	// trust on first use against ~/.xpc/known_hosts.
	HostKeyCallback ssh.HostKeyCallback
	// KnownHostsPath overrides the default ~/.xpc/known_hosts location.
	KnownHostsPath string
}

DialOptions configures Dial.