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FastAPI Deployment

Deploy Python FastAPI applications in a production-ready environment on KloudBean.

Overview​

On KloudBean, you get a complete production-ready stack to build and host high-performance FastAPI applications.

You get:

  • Git integration to pull your code on the server
  • SSH access to the server to run commands manually and using ADM tool for quick deployment
  • File Manager access to add, update and manage files with ease
  • Optimized and configured Uvicorn for serving your FastAPI application

Launching New FastAPI Application​

note

If you already have a server and want to launch an app on it, go to Applications → Add Application and add a FastAPI app on an existing server.

In this example, we will create a brand new server.

In order to launch your first FastAPI app on a new server, navigate to the server provision page:

  1. Select Cloud Provider (your choice)
  2. Select Application (FastAPI)
  3. Select Datacenter with nearest location
  4. Add Application Name
  5. Add Server Name
  6. Select Server size depending on needs (for FastAPI build minimum recommended size is 2-4GB)

Launch FastAPI Application

Click on Launch button and proceed with the payment process (trial or payment).

Once payment is completed, server with FastAPI app provisioning will be initiated.

Wait for a while; it will take 5-7 minutes to create your server, configure and deploy a high-performance web stack.

By default, on a new server you will get the following stack versions:

  • Python > 3.11
  • FastAPI (latest)
  • Uvicorn
  • MariaDB > 10.6 (optional)

Accessing Application Administration​

Once your server is ready, in order to access your FastAPI app, select "Apps" from the header menu to go to the Applications page.

On this page, you will see your application in active status.

Application Status

Click on it to navigate to "Application Administration" > "Access" section.

On this section, you will see:

  1. Application default access URL
  2. Server public address to point your custom domain to it

Application Access

Deploying Your Code​

The next step is to deploy your code.

In order to deploy your code, navigate to the "Code Delivery" tab.

Here, on the first tab → "Git deployment":

  1. Click on "Enable Git Integration"
  2. Copy SSH public key and add it to your SCM provider (GitHub, GitLab)

Enable Git Integration

  1. Copy your repo URL and add it here in "Git Repository URL", select branch and "Clone Repository"

Clone Repository

In this example, we're going to deploy an example FastAPI app:

https://github.com/pixegami/fastapi-tutorial.git

Read the detailed guide on connecting Git.

Once the repo is cloned, the next step is to run the deployment. Click on "Pull & Deploy".

Pull & Deploy

Once you click, it will initiate the build process automatically by doing the following at the backend:

Build Process

  • Take latest repo pull
  • Adding bean.conf to add FastAPI basic configuration
  • Installing packages
  • Updating Uvicorn configs
  • Starting workers

Updating bean.conf Script​

Application basic info is mentioned in a file named bean.conf.

It is important to give the app name with this convention: <your-app-folder>:app

Also specify:

  • App directory (mostly /)
  • Number of workers

In order to create this file, go to the fastapi-src directory and create this file. If the file already exists, update the content.

Add File Using File Manager​

Add the bean.conf file using File Manager:

File Manager

Or Using Command Through Shell​

nano /home/admin/hosted-sites/<app_system_user>/fastapi-src/bean.conf

And add the following content. In this example, we're adding basic configuration:

APP_NAME=<your-app-folder>:app
APP_DIR=/
WORKERS=8

Bean Config

Updating/Adding Environment (.env) File​

If you need to add or update the .env file, you can access it using File Manager or optionally using shell.

Navigate to the third tab "FileManager" and click "Launch FileManager" button to open it in a new tab.

Once you are in File Manager, in the fastapi-src directory, you can create a new file .env by clicking on "New file" from the left sidebar.

Give the file name and click "Create".

Create .env File

It will open a new file in the editor. Add your required environment variables. For example:

APP_URL=https://fastapi-232200305.kloudbeansite.com
DB_HOST=localhost
DB_NAME=kb_aro6c30zoz
DB_USERNAME=kb_aro6c30zoz
DB_PASSWORD=31vYF9Dc65gHbV742m

In order to get database access credentials, read the detailed guide on Viewing Database Credentials.

Environment Variables

Once updated, click on the "Save" icon on the top right corner of the editor, and it will be saved.

Viewing Build Logs​

If you see your build failed or you need to see build and installation logs, click on your current build and a prompt will open to view the logs.

View Build Logs

Once your application is started, you can access it from the access URL:

"Application Administration" → Access → Access URL

If you are seeing 503, that means your application is not up and has some errors.

In order to view application logs:

  • You can view logs using File Manager
  • Or by SSH into the server

Go to directory: /home/admin/hosted-sites/<app_system_user>/app-logs

note

Important: It is important to check your application logs if your site is responding with a 503 gateway error. It shows that the application is not running.

In this directory, application logs are being added in the following log files:

  • app.info.log → information logs
  • app.error.log → error logs

You can open these files using File Manager to view the errors.

Deployment Using ADM Tool (Application Deployment Manager)​

Application Deployment Manager (ADM) is one of KloudBean's features that enables you to deploy your app quickly by just executing one command. It supports all FastAPI and Python-based applications.

In order to perform deployment using the ADM tool, you have to access your server using shell.

Read the detailed guide on how to SSH server on KloudBean.

Optionally Enable Python Virtual Environment​

When you launch any Python-based framework on KloudBean, you get automatically configured a virtual Python environment with each app. You don't have to manually create one.

In order to enable the virtual environment, run this command:

source /home/admin/hosted-sites/<app_system_user>/venv_<app_system_user>/bin/activate

And your virtual environment will be activated.

Activate Virtual Environment

Once you are connected to the server, run the following ADM command:

sudo adm

or

sudo adm <app_system_user>

→ to directly execute for the required application.

ADM Command

If you run this command without app_system_user, then you will have to select the app by providing its number in the prompt and click hit enter.

It will start the deployment process with the logs and progress details on the shell screen.

ADM Deployment

note

Information: While executing deployment through ADM, you will see the port as well to get to know on which port the app is running.

Handling Build Errors​

If you are seeing the build has failed, you can see build logs.

While executing ADM, you might see the app failed. Carefully watch the error and try to fix it.

Here are some common FastAPI build errors and how to fix them:

1. Import Errors​

Error: ModuleNotFoundError: No module named 'xxx'

Solution:

  • Ensure all dependencies are listed in your requirements.txt
  • Check that package names are spelled correctly
  • Verify Python version compatibility with the packages

2. ASGI Application Not Found​

Error: Could not import application 'app:app'

Solution:

  • Verify your bean.conf has the correct APP_NAME format: <module>:<variable>
  • Ensure your FastAPI app instance is named app (e.g., app = FastAPI())
  • Check that the file structure matches the APP_DIR in bean.conf

3. Port Already in Use​

Error: Address already in use

Solution:

  • This usually resolves automatically on redeployment
  • If persistent, check if another process is using the port
  • Restart the application using ADM tool

4. Database Connection Errors​

Error: Database connection failures

Solution:

  • Verify database credentials in .env file
  • Check that database server is running and accessible
  • Ensure database name, user, and password are correct
  • Verify network connectivity between app and database

5. Dependency Version Conflicts​

Error: Package version conflicts during installation

Solution:

  • Pin specific versions in requirements.txt (e.g., fastapi==0.104.1)
  • Remove conflicting packages and use compatible alternatives
  • Update packages to latest compatible versions

Once the error is fixed, then run the build again using "Pull & Deploy" or using the ADM tool from shell.

Next Steps​