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SSH commands

@jalsoedesign/dockline-ssh-client provides scoped SSH command execution and SFTP transfers. It is independently installable; core, FTP and SFTP consumers do not need to install it.

npm install @jalsoedesign/dockline-ssh-client

This new workspace must be published before that registry command is available. Repository users can build it with npm run build --workspace @jalsoedesign/dockline-ssh-client.

import {SshClient} from '@jalsoedesign/dockline-ssh-client';

const client = new SshClient({
    host: 'server.example.com',
    port: 22,
    username: 'deployer',
    privateKeyPath: '/home/me/.ssh/deployer',
    hostFingerprint: process.env.SSH_HOST_FINGERPRINT,
});

await client.withConnection(async server => {
    const result = await server.exec('uptime');

    console.log(result.stdout);

    await server.download({
        sourceFile: '/var/backups/export.sql',
        destinationFile: './backups/export.sql',
    });

    await server.exec('systemctl', ['restart', 'website'], {
        sudo: true,
        timeout: '1m',
    });
});

Without an explicit fingerprint or a supplied trust(host, port, fingerprint) callback, connections reject unknown hosts. The application owns trust persistence and any prompt UI. Supply optional ask, log, signal and directory callbacks/settings as the constructor's second argument. ask receives an input/password challenge and returns its answer. No CLI prompt implementation is bundled.

withConnection authenticates and closes its connection in finally. Passwords, private-key passphrases, explicit SSH agents and keyboard-interactive authentication are supported. Agent forwarding is not enabled. An SFTP account does not necessarily have command-execution permission.

Command API

• exec(program, args?, options?) quotes each argument for a POSIX remote shell.
• shell(command, options?) explicitly executes sh -c for shell expressions.
• asUser(username, callback) runs scoped commands through sudo -u.
• download({sourceFile, destinationFile, timeout?, maxBytes?}) uses a temporary local file before replacement.
• upload({sourceFile, destinationFile, timeout?, maxBytes?}) streams a local file using Dockline SFTP.

Exec options include timeout, sudo (boolean or target username) and allowFailure. Results include code, stdout and stderr; returned output retains the last 1 MiB per stream while log receives streamed output. Nonzero exit codes reject by default. Timeouts accept positive milliseconds or strings such as 30s, 5m and 1h; the default command/transfer deadline is one hour. Commands are never automatically retried.

The transfer helpers open separate SFTP connections with the same resolved credentials and host verifier. They have no default byte cap. A transfer does not inherit sudo privileges: files created by privileged commands must be readable by the SFTP user.

Sudo defaults to noninteractive mode. Set sudo.password: 'prompt' with an ask callback, or sudo.passwordEnv, when a password is required. Passwords travel through stdin when the sudo prompt appears, not command arguments. Servers requiring an interactive TTY are outside this API's initial scope.

Cancellation requests command termination and closes channels. The remote server may ignore a signal; inspect remote state before retrying. Remote Windows shell syntax and persistent interactive sudo su sessions are not supported.

See the SSH package source.

PuTTY key files

privateKeyPath accepts PPK v3 keys directly, including encrypted keys when passphrase is supplied. SSH commands and SFTP transfers share the same in-memory reader. See key formats and resource limits.