How to…¶

This section contains practical, step-by-step guides for deploying applications with Fujin.

Guides

Prerequisites¶

Linux Box¶

fujin has no strict requirements on the virtual private server (VPS) you choose, apart from the fact that it must be running a recent version of Ubuntu or a Debian-based system. I’ve mainly run my tests with various versions of Ubuntu: 20.04, 22.04, and 24.04. Other than that, use the best option for your app or the cheapest option you can find.

SSH Access: You must have root access to the server via SSH. - If you are using a cloud provider (DigitalOcean, Hetzner, AWS, etc.), you usually add your public SSH key during the server creation process. - Alternatively, you might be given a root password. Fujin can work with password-based authentication, but SSH keys are recommended for security and convenience.

Domain name¶

You can get one from popular registrars like namecheap or godaddy. If you just need something to test this tutorial, you can use sslip, which is what I’ll be using here.

If you’ve bought a new domain, create an A record to point to the server IP address.

Server Setup¶

It is highly recommended to create a dedicated user for deployment instead of using root. This improves security by limiting the privileges of the application.

The process involves three steps:

Configure Fujin to use root: Initially, Fujin needs to connect as root to create the new user. Ensure your fujin.toml has the root user configured:
```
[[hosts]]
user = "root"
address = "your-domain.com"
```
Create the user: Run the following command to create a new user (e.g., fujin) on the server. This command creates the user, grants passwordless sudo access, and copies your SSH keys from the root user to the new user.
```
fujin server create-user fujin
```
Switch to the new user: Update your fujin.toml to use the newly created user for all future operations.
```
[[hosts]]
user = "fujin"
address = "your-domain.com"
```

Now you are ready to deploy your application using this dedicated user.

Common Operations¶

fujin up: Provisions the server (installs dependencies) and deploys the app. Use this for the first deploy.
fujin deploy: Updates configuration files (Systemd, Caddy) and the application code. Use this if you changed fujin.toml or templates.

FAQ¶

What about my database?¶

Fujin currently focuses on application deployment. For databases, you can:

Manually install PostgreSQL/MySQL on your server.
Use a managed database service.
Wait for upcoming container support (see Issue #17).