SSH Nexus

Advanced SSH automation hub with intelligent connection management and network device support. Built with ❤️ by Sarryaz
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Overview

This node connects to remote systems via SSH to retrieve system information, specifically including memory details when the "Memory Info" operation under the "System Information" resource is selected. It executes the free -h command on the target system to obtain human-readable memory usage statistics.

Common scenarios for this node include:

  • Monitoring server memory usage in automated workflows.
  • Collecting system metrics for reporting or alerting.
  • Integrating with infrastructure management tools to gather real-time system stats.

Example use case: Automatically fetch memory info from multiple Linux servers to track available RAM and swap usage, then trigger alerts if free memory falls below a threshold.

Properties

Name Meaning
Configuration Mode Choose how to configure the SSH connection:
- Use Credentials: Use stored SSH credentials (recommended for security).
- Dynamic Parameters: Use dynamic parameters from previous nodes or environment variables.
Dynamic Host Hostname or IP address of the target system (required if using Dynamic Parameters mode). Supports expressions and environment variables.
Dynamic Port SSH port number (default 22) for the connection (used in Dynamic Parameters mode).
Dynamic Username Username for SSH login (required if using Dynamic Parameters mode). Supports expressions and environment variables.
Dynamic Password Password for SSH login (optional, supports expressions and environment variables; used in Dynamic Parameters mode).
Dynamic Private Key Private key content for SSH authentication (optional, supports expressions and environment variables; used in Dynamic Parameters mode).
Advanced Options Collection of advanced settings:
- Command Timeout (ms): Max wait time for command execution.
- Output Parsing: How to parse command output (smart, JSON, table, raw, none).
- Continue on Error: Whether to proceed on errors.
- Cipher Override: Select cipher algorithms.
- Try Fallback Ciphers: Enable fallback ciphers.
- Retry Delay (ms): Delay between retries.
- Verbose Logging: Enable detailed debug logs.
- Line Ending Style: CRLF or LF.
- Device Type: Select device type for optimized handling (generic, Cisco IOS, Aruba OS, etc.).

Output

The node outputs an array of items, each containing a json object with the following structure for the Memory Info operation:

  • raw: Raw command output as a string.
  • lines: Array of non-empty lines from the output.
  • wordCount: Number of words in the output.
  • hasError: Boolean indicating if parsing detected an error (usually false).
  • stderr: Standard error output from the command (if any).
  • exitCode: Exit code of the executed command.
  • parseOutput: The parsing mode used (e.g., smart, json, raw).
  • Additional fields may be present depending on parsing mode.

The output represents the memory usage information retrieved by running free -h on the remote system, typically showing total, used, free, shared, buff/cache, and available memory in a human-readable format.

No binary data output is produced by this operation.

Dependencies

  • Requires an SSH server accessible on the target host.
  • Needs either stored SSH credentials or dynamic SSH connection parameters.
  • Uses the node-ssh library internally for SSH connections.
  • No additional external services are required.
  • For secure operation, an API key credential or private key must be configured in n8n for SSH authentication.

Troubleshooting

  • Connection failures: Ensure the SSH server is reachable, credentials are correct, and network/firewall rules allow SSH traffic.
  • Invalid host format: Hostnames must only contain letters, numbers, dots, and hyphens.
  • Port out of range: SSH port must be between 1 and 65535.
  • Command timeout: If commands take longer than the specified timeout, increase the "Command Timeout" setting.
  • Parsing issues: If output parsing fails or returns unexpected results, try changing the "Output Parsing" option to "Raw Text" or "No Parsing".
  • Permission denied: Verify that the SSH user has permission to execute the free -h command.
  • Legacy cipher errors: If connection fails due to cipher mismatches, enable fallback ciphers or override cipher selection in advanced options.

Links and References

Discussion