SSH NexusInstall

Overview

The Execute Multiple Commands operation of this SSH Nexus node enables users to run multiple shell commands sequentially on a remote system over SSH. It supports flexible input formats for commands, including plain text lists and JSON arrays, and allows customization of execution parameters such as wait time between commands and output parsing style.

This operation is beneficial in scenarios where complex automation or configuration tasks require running several commands in order, for example:

• Network device configuration or status checks by sending multiple show or config commands.
• Batch maintenance scripts on Linux servers.
• Collecting various system information outputs in one go.

Practical examples include:

• Running a list of diagnostic commands on a router: show version, show interfaces, show ip route.
• Executing a sequence of Linux commands to update software, clean caches, and restart services.
• Sending multiple commands with custom delays to avoid overwhelming the remote device.

Properties

Output

The output JSON contains a commands array with an entry per executed command. Each command result includes:

• command: The executed command string.
• exitCode: Numeric exit code returned by the command.
• stderr: Standard error output text.
• stdout or parsed output fields depending on parsing option:
  • If parsing is enabled (smart, json, table, raw), structured data or formatted text is provided.
  • If parsing is disabled (none), raw output and basic stats like line count and word count are included.
• parseOutput: The parsing mode used.
• commandIndex: Position of the command in the sequence (1-based).
• totalCommands: Total number of commands executed.
• Optional cwd: Working directory if specified.
• Optional hasError: Boolean indicating if output parsing detected errors.

If binary data were involved (not applicable here), it would be included in the binary property.

Example snippet of output JSON structure:

{
  "commands": [
    {
      "command": "show version",
      "exitCode": 0,
      "stderr": "",
      "stdout": "...",
      "parseOutput": "smart",
      "commandIndex": 1,
      "totalCommands": 3
    },
    {
      "command": "show interfaces",
      "exitCode": 0,
      "stderr": "",
      "stdout": "...",
      "parseOutput": "smart",
      "commandIndex": 2,
      "totalCommands": 3
    }
  ]
}

Dependencies

• Requires an active SSH server accessible via network.
• Needs either stored SSH credentials configured in n8n or dynamic SSH connection parameters supplied at runtime.
• Uses the node-ssh library internally for SSH connections.
• Supports private key or password authentication.
• For network devices, device-specific command sets and prompt handling are built-in.
• No additional external services required beyond SSH access.

Troubleshooting

• Invalid host format error: When using dynamic parameters, the host must only contain letters, numbers, dots, and hyphens. Avoid spaces or special characters.
• Port number out of range: Ensure the SSH port is between 1 and 65535.
• Empty commands list: The node throws an error if no valid commands are found; ensure commands are not empty or commented out entirely.
• Potentially dangerous commands blocked: Commands containing destructive patterns like rm -rf /, dd if=/dev/zero, mkfs, shutdown, or reboot are rejected to prevent accidental damage.
• SSH connection failures: Check credentials, network connectivity, and cipher compatibility. Enabling verbose logging can help diagnose handshake or authentication issues.
• Command timeout: Increase the command timeout if commands take longer than default 30 seconds.
• Continue on error: Enable this option to allow subsequent commands to run even if some fail.
• Parsing errors: If output parsing fails, try switching to raw or none parsing modes.

Links and References

• SSH Nexus Node Documentation (hypothetical)
• node-ssh GitHub Repository
• SSH Protocol Overview
• Common SSH Ciphers
• Network Device CLI Automation Best Practices