Reimage Your Server for Langflow Installation

Use our one-click installer to quickly set up Langflow on your Self-Managed VPS and Virtual Dedicated Server (VDS). This guide shows you how to clear your current server and deploy Langflow from your dashboard.

System Requirements

Before deploying, ensure your server meets the following minimum hardware requirements. For a stable production deployment, we recommend using higher specifications than the minimum requirements.

How to Reimage Your Server for Langflow Installation

This guide walks you through installing and setting up Langflow using the Bluehost Portal.

1. Log in to your Bluehost Portal.
2. In the left-hand menu, click the Hosting tab.

   
    

3. Click the Manage button on the hosting package you want to reimage.

   
    

4. Click the Reimage button.

   
    

5. Select the Applications tab.

   
    

6. From the list, locate Langflow and click Select.

   
    

7. To confirm, type "reimage" and then click Proceed to start the process.

   
    

8. Wait a few minutes while the installation completes.

   
    

9. Once completed, you will see Langflow listed in the Server Image section.

   
    

How to Set Up and Manage a Langflow Server

Langflow is an open-source low-code platform for building and deploying AI-powered applications and multi-agent workflows. It provides a visual drag-and-drop interface for composing LLM pipelines and integrating with OpenAI, Anthropic, Ollama, vector stores, and dozens of other data sources.

This guide outlines how the server operates out of the box and the steps required to start building your AI pipelines securely.

Phase 1: The Automatic First Boot (Behind the Scenes)

Note: Initial startup takes 2-5 minutes while Langflow initializes its SQLite database and serves frontend assets. A background cloud-init script handles all initial provisioning and self-deletes to prevent re-running.

1. Security Generation
   The system generates a random superuser password and a secret key (LANGFLOW_SECRET_KEY) to encrypt your API keys. It writes these credentials securely to /root/.app_secrets.
2. HTTPS / SSL Setup
   The server detects its public IP and requests a Let's Encrypt TLS certificate via Certbot so your browser shows a secure connection. If on a private network, it falls back to a self-signed certificate. Nginx is configured automatically to reverse-proxy traffic to the backend.
3. Application Launch
   A program called Supervisor starts the Langflow backend (safely bound to 127.0.0.1:7860, so it isn't directly exposed to the internet).

Phase 2: Reset Your Root Password

1. Log in to your Bluehost Portal.
2. In the left-hand menu, click the Hosting tab.

   
    

3. Locate the server you want to manage, then click View Details in the bottom-left corner to expand the section and access additional server information.

   
    

4. Click the Reset Password.

   
    

5. In the pop-up window, type your new root password, then click Reset Password again to confirm and save the changes.

   
    

Phase 3: Connect To Your Server Through SSH

Now that the automated setup is complete, you can retrieve your generated credentials and log in.

1. Connect to your server via SSH.
   Open your computer's terminal (or an SSH client like PuTTY) and run the following command to log into your server as the administrator, using your server's public IP address:
   Replace your_server_ip with your actual server IP address.

   ssh root@your_server_ip
   

   Follow the prompts and enter the new root password you created in the step above.
2. The login credentials are shown in the MOTD (Message of the Day) each time you connect, or you can print them out by running:
   Copy

   cat /root/.app_secrets

   Example Output:

   root@server-646882:~# cat /root/.app_secrets
   LANGFLOW_SUPERUSER=admin
   LANGFLOW_SUPERUSER_PASSWORD=abc1234e47e30fe7
   LANGFLOW_SECRET_KEY=T3abc1234ea300d130fa00f408bfa86af22aef9be6a6
   SITE_URL=https://12.3.456.789
   
   

Phase 4: Access the Web Panel

Now, you will leave the terminal for a moment and move to your web browser. 

1. Navigate to the panel:  Open your web browser and go to https://<server-ip>. HTTP (port 80) redirects to HTTPS automatically. Note: If using a private IP with a self-signed certificate, you will need to accept your browser's security warning to proceed.

   Example: [http://12.3.456.789] (http://12.3.456.789)

2. Log in: Use the admin username and the password you retrieved in Phase 3, Step 2, to access your dashboard.

   
    

Phase 5: Building Flows and Connecting LLMs

1. Create your first flow
   Click Create first flow to start from a blank canvas, or choose a starter template from the gallery to explore the interface. Drag components from the left sidebar onto the canvas and connect their inputs and outputs.

   
    

2. Connect an LLM provider
   Add an OpenAI, Anthropic, Ollama, or other model component to your flow by clicking the Configure Model Providers.

   
    

3. Enter your API keys
   Paste your API key into the api_key field.

   Example formats:

   OpenAI key: sk-...
   Anthropic key: sk-ant-...
   Ollama base URL: http://localhost:11434  (if installed on the same host)
   
   

Phase 6: Post-Deployment Configurations

While the automated setup handles the basics, you may eventually want to update your password or manually refresh your SSL certificate.

1. Change your superuser password
   1. Log in to your server via SSH and edit the environment file:
      Copy

      nano /etc/default/langflow
   2. Update the password value:
      Copy

      LANGFLOW_SUPERUSER_PASSWORD=yournewpassword
   3. Save the file ( Ctrl + O, Enter, Ctrl + X) and restart the service:
      Copy

      supervisorctl restart langflow
2. Manually Re-request an SSL Certificate
   If you ever need to manually re-request an SSL certificate tied to a public IP after the initial deployment, run:
   Copy

   /opt/certbot/bin/certbot certonly \ --webroot --webroot-path /var/www/letsencrypt \ -m [email protected] --agree-tos --non-interactive \ --ip-address nginx -t && systemctl reload nginx

Phase 7: Day-to-Day Management

The image also sets up tools to help you manage the server going forward. The firewall (UFW) is already configured to only allow essential traffic (Ports 22, 80, and 443), and weekly log rotations are enabled. Note: Minimum system resources recommended 4 vCPUs and 8 GB RAM for a comfortable experience.

If you ever need to troubleshoot, update, or back up the system, you can use these core commands:

• Check health status:
  Copy

  supervisorctl status langflow
• Reboot the application:
  Copy

  supervisorctl restart langflow
• View live application logs:
  Copy

  tail -f /var/log/langflow/langflow.log
• Upgrade Langflow to the newest version:
  Copy

  sudo -u langflow /opt/langflow/venv/bin/pip install --upgrade langflow supervisorctl restart langflow
• Backup your persistent data:
  Copy

  supervisorctl stop langflow tar -czf langflow-backup.tar.gz /opt/langflow/data /root/.app_secrets supervisorctl start langflow

Additional Information and Example Documentation Output

You can run cat /root/README.md to see more information and useful commands:

Example Output:

root@server-123456:~# cat /root/README.md
# Langflow

## Description

Langflow is an open-source low-code platform for building and deploying AI-powered applications and multi-agent workflows. It provides a visual drag-and-drop interface for composing LLM pipelines and integrating with OpenAI, Anthropic, Ollama, vector stores, and dozens of other data sources and tools.

This image ships Langflow on Ubuntu 24.04, installed in a Python virtual environment and managed by Supervisord. Nginx sits in front as a reverse proxy with automatic TLS termination. On first boot, a Let's Encrypt certificate is provisioned (or a self-signed fallback for private networks).


## Services

| Service    | Port     | Purpose                                                   |
|------------|----------|-----------------------------------------------------------|
| Langflow   | 7860     | Langflow FastAPI backend (internal only, bound to 127.0.0.1) |
| Nginx      | 80, 443  | Reverse proxy, TLS termination, WebSocket upgrade         |
| Supervisor | n/a      | Process supervisor managing the Langflow backend          |
| OpenSSH    | 22       | Remote access (UFW rate-limited)                          |


## How to Use

### 1. Access Langflow

Wait 3-5 minutes after first boot while Langflow initialises its database and serves frontend assets. Then open your browser to:

```
https://
```

HTTP (port 80) redirects to HTTPS automatically. If the server has a public IP, a Let's Encrypt certificate is issued. On private networks a self-signed certificate is used; accept the browser warning to proceed.

### 2. Log in

A superuser account is created automatically at first boot. Retrieve your credentials with:

```bash
cat /root/.app_secrets
```

The credentials are also shown in the MOTD each time you SSH in. Log in with the `admin` username and the generated password.

### 3. Create your first flow

Click **New Flow** to start from a blank canvas, or choose a starter template from the gallery to explore the interface. Drag components from the left sidebar onto the canvas and connect their inputs and outputs.

### 4. Connect an LLM provider

Add an **OpenAI**, **Anthropic**, **Ollama**, or other model component to your flow and paste your API key into the `api_key` field. Keys are encrypted at rest using `LANGFLOW_SECRET_KEY`.

```
OpenAI key     : sk-...
Anthropic key  : sk-ant-...
Ollama base URL: http://localhost:11434  (if Ollama is installed on the same host)
```

### 5. Change your password

To update the superuser password, edit `/etc/default/langflow` and set a new value:

```
LANGFLOW_SUPERUSER_PASSWORD=yournewpassword
```

Then restart the service:

```bash
supervisorctl restart langflow
```

### 6. SSL / HTTPS certificate behaviour

On first boot, TLS is provisioned automatically:

- **Public IP** - certbot requests a Let's Encrypt certificate tied to the server's public IP. No browser warning.
- **Private IP** - a self-signed certificate is generated as a fallback. HTTPS still works but browsers will warn.

To manually re-request a certificate after deployment:

```bash
/opt/certbot/bin/certbot certonly \
  --webroot --webroot-path /var/www/letsencrypt \
  -m [email protected] --agree-tos --non-interactive \
  --ip-address 

nginx -t && systemctl reload nginx
```

## Useful Commands

```bash
# Service management
supervisorctl status langflow           # Check Langflow status
supervisorctl restart langflow          # Restart Langflow
supervisorctl stop langflow             # Stop Langflow
supervisorctl start langflow            # Start Langflow
systemctl restart nginx                 # Restart nginx

# Logs
tail -f /var/log/langflow/langflow.log        # Live application log
tail -f /var/log/langflow/langflow-error.log  # Live error log
tail -f /var/log/nginx/access.log             # Nginx access log
tail -f /var/log/nginx/error.log              # Nginx error log

# Health check
curl http://127.0.0.1:7860/health       # Backend health endpoint

# Upgrade Langflow
sudo -u langflow /opt/langflow/venv/bin/pip install --upgrade langflow
supervisorctl restart langflow

# Backup persistent data
supervisorctl stop langflow
tar -czf langflow-backup.tar.gz /opt/langflow/data /root/.app_secrets
supervisorctl start langflow

# Check UFW firewall rules
ufw status
```

## First Boot Behaviour

On first boot the cloud-init per-instance script `/var/lib/cloud/scripts/per-instance/001_onboot`:

1. Generates a random superuser password and secret key
2. Writes credentials to `/root/.app_secrets` (mode 0600)
3. Patches `/etc/default/langflow` with the generated values
4. Detects the server's public IP address
5. Requests a Let's Encrypt TLS certificate via certbot (falls back to self-signed if unreachable)
6. Rewrites the nginx config with the full HTTPS reverse-proxy block and reloads nginx
7. Writes the site URL to `/root/.app_secrets`
8. Starts Supervisor and brings up the Langflow backend
9. Self-deletes to prevent re-running on cloud-init reset

Initial startup takes 2-5 minutes while Langflow initialises its SQLite database and generates a secret key.


## Configuration Files Reference

| File                                           | Purpose                                         |
|------------------------------------------------|-------------------------------------------------|
| `/etc/default/langflow`                        | Environment variables (port, auth, DB, secrets) |
| `/opt/langflow/run.sh`                         | Wrapper script that loads env file and starts Langflow |
| `/etc/supervisor/conf.d/langflow.conf`         | Supervisor program definition                   |
| `/etc/nginx/sites-available/langflow`          | Nginx site config (rewritten at first boot)     |
| `/etc/logrotate.d/langflow`                    | Log rotation config (weekly, 5 backups)         |
| `/opt/langflow/data/`                          | SQLite database, flow exports, cache, secret key |
| `/root/.app_secrets`                           | Site URL written at first boot                  |
| `/var/log/langflow/langflow.log`               | Application stdout log                          |
| `/var/log/langflow/langflow-error.log`         | Application stderr log                          |


## Security Hardening

| Hardening       | Detail                                                          |
|-----------------|-----------------------------------------------------------------|
| UFW firewall    | Only ports 22, 80, 443 open - default deny inbound             |
| SSH             | Password authentication disabled, key-only access              |
| Langflow        | Bound to 127.0.0.1:7860 - not reachable directly from outside  |
| Secret key      | `LANGFLOW_SECRET_KEY` encrypts API keys stored in flows        |
| Auth            | Login required by default; superuser credentials generated at first boot |
| TLS             | HTTPS enforced; HTTP redirects to HTTPS                        |


## Image Contents

This image installs and configures:

- Langflow (latest) in a Python virtual environment at `/opt/langflow/venv`
- Supervisord managing the Langflow process as the `langflow` system user
- Nginx as a reverse proxy with HTTP -> HTTPS redirect and WebSocket support
- Certbot (via pip) for automatic Let's Encrypt TLS certificates
- UFW firewall with ports 22, 80, and 443 open
- Log rotation at `/etc/logrotate.d/langflow`
- This README at `/root/README.md`


## Minimum Resources

| Resource | Minimum  | Recommended |
|----------|----------|-------------|
| CPU      | 2 vCPUs  | 4 vCPUs     |
| RAM      | 4 GB     | 8 GB        |
| Disk     | 20 GB    | 30 GB       |

> Langflow loads a significant number of ML-related Python packages at startup. 4 GB RAM is the practical minimum for a stable instance; 8 GB is comfortable for running larger flows or multiple concurrent users.


## Links

- Manage: [https://SERVER_IP/](https://SERVER_IP/)
- Documentation: [https://docs.langflow.org](https://docs.langflow.org)
- Quickstart guide: [https://docs.langflow.org/get-started-quickstart](https://docs.langflow.org/get-started-quickstart)
- Components reference: [https://docs.langflow.org/components-overview](https://docs.langflow.org/components-overview)
- Integrations (LLM providers): [https://docs.langflow.org/integrations-langchain](https://docs.langflow.org/integrations-langchain)
- GitHub: [https://github.com/langflow-ai/langflow](https://github.com/langflow-ai/langflow)

Summary

Reimaging your Self-Managed VPS and Virtual Dedicated Server (VDS) allows you to quickly deploy pre-configured environments like Langflow via a one-click installer. However, because this process completely overwrites your current server disk, it is vital to back up any critical data before proceeding. If you need to run multiple environments or preserve existing data, opt for a manual installation via SSH instead.