@feitas/node-red-ssh-dynamic 0.1.2

A Node-RED SSH node that accepts all connection parameters (host, port, username, password) dynamically from msg object

npm install @feitas/node-red-ssh-dynamic

@feitas/node-red-ssh-dynamic

A dynamic SSH client node for Node-RED. All connection parameters are read from msg — nothing is hardcoded in the node configuration. This makes it easy to connect to different servers at runtime without redeploying.

Features

• 🔄 Fully dynamic — host, port, username, and password all come from msg at runtime
• 🔌 Persistent connections — interactive SSH shell sessions stay open between messages, preserving shell state (working directory, environment variables)
• 🏊 Connection pooling — automatically reuses existing connections based on host:port:username
• 🌐 WebSocket session mode — each WebSocket client (msg._client) gets its own isolated SSH session; ideal for web-based terminal UIs
• 📦 Zero static config — only an optional name field in the node editor; everything else flows through messages
• ⚡ Auto-reconnect — sending a message to a closed session automatically reopens the connection
• 📤 Dual output — msg.payload for stdout and msg.stderr flag for stderr data

Installation

Via Node-RED Palette Manager

1. Open Node-RED
2. Go to Manage Palette → Install
3. Search for @feitas/node-red-ssh-dynamic
4. Click Install

Via npm

cd ~/.node-red
npm install @feitas/node-red-ssh-dynamic

Or from the Node-RED data directory:

npm install @feitas/node-red-ssh-dynamic

Then restart Node-RED.

Usage

Node Configuration

Drag the ssh-dynamic node from the palette (category: network) onto your flow. The only configurable field is an optional Name.

All SSH parameters come from incoming messages — no static host/port/username/password needed.

Input (msg) Properties

Output (msg) Properties

Connection Management

Host-Based Mode (Default)

When msg._client is not present, connections are keyed by host:port:username:

• Same credentials → connection is reused (shell state preserved)
• Different host/port/username → old connection closes, new one opens
• Changed password → password is updated on the cached connection entry

WebSocket Session Mode

When msg._client is present (automatically set by websocket-in nodes), each client gets its own dedicated SSH session:

1. First message from a client must include msg.host, msg.username, and msg.password
2. All subsequent messages from that client only need msg.payload — credentials are cached
3. Multiple browser tabs each get their own msg._client, connecting to different hosts through a single node instance

If credentials are missing on the first message and only one connection exists in the pool, the node auto-binds the new session to that existing connection.

Examples

Example 1: Basic Command via Inject Node

// In a Function node before ssh-dynamic
msg.host = "192.168.1.100";
msg.port = 22;
msg.username = "admin";
msg.password = "secret";
msg.payload = "uname -a\n";
return msg;

Flow: inject → function → ssh-dynamic → debug

Example 2: Interactive Shell Session

Send multiple commands that share state:

// First message
msg.host = "192.168.1.100";
msg.username = "admin";
msg.password = "secret";
msg.payload = "cd /var/log\n";
return msg;

// Second message (connection reused, working directory preserved)
// Only payload needed — host/username/password cached
msg.payload = "ls -la\n";
return msg;

Example 3: Web-Based Terminal

// Function node between websocket-in and ssh-dynamic
const clientId = msg._client;
const credsKey = "ssh:" + clientId;
let creds = flow.get(credsKey);

if (!creds) {
    // First message — set credentials
    creds = {
        host: msg.host || "192.168.1.100",
        port: msg.port || 22,
        username: msg.username || "admin",
        password: msg.password || "secret"
    };
    flow.set(credsKey, creds);
}

msg.host = creds.host;
msg.port = creds.port;
msg.username = creds.username;
msg.password = creds.password;
// msg.payload and msg._client pass through
return msg;

Flow: websocket-in → function → ssh-dynamic → websocket-out

Example 4: Connecting to Multiple Hosts

// Dynamic routing based on topic
if (msg.topic === "server-a") {
    msg.host = "10.0.0.1";
    msg.username = "admin";
    msg.password = "pass-a";
} else if (msg.topic === "server-b") {
    msg.host = "10.0.0.2";
    msg.username = "root";
    msg.password = "pass-b";
}
msg.payload = "uptime\n";
return msg;

Each host gets its own pooled connection.

License

MIT — see package.json for details.

Dependencies

• ssh2 — SSH2 client library for Node.js

Author

@feitas