LoadForge allows you to upload, create, and manage files for your load tests. You can upload CSV, JSON, or TXT files (maximum 5MB) to use in your test scripts.
File management

A file being managed in LoadForge

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How Files Work in LoadForge

Files are automatically uploaded to your load generators and stored in the files/{file_name} directory. This makes it easy to access your data files from within your load test scripts. This feature is particularly useful for:
  • Large user lists for authentication testing
  • Test datasets for API or form submissions
  • Configuration files for complex test scenarios
  • CSV data for data-driven testing

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Uploading Files

You can upload files through the LoadForge interface:
  1. Navigate to the File Management section
  2. Click Upload File or Create Blank File
  3. Select your file or create a new one
  4. The file will be available in the files/ directory on all load generators
Name the file correctly to get better editing capabilities. For example, .csv files load a CSV editor.

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Using Files in Locust Tests

Here are some examples of how to use uploaded files in your Locust test scripts:

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Loading a JSON User List

import json
import random
from locust import HttpUser, task, between

class UserBehavior(HttpUser):
    wait_time = between(1, 5)
    
    def on_start(self):
        # Load the user credentials from the uploaded JSON file
        with open('files/userlist.json', 'r') as f:
            self.users = json.load(f)
        
        # Select a random user from the list
        user_data = random.choice(self.users)
        self.username = user_data['username']
        self.password = user_data['password']
        
        # Log in with the selected user
        self.client.post("/login", {
            "username": self.username,
            "password": self.password
        })
    
    @task
    def view_dashboard(self):
        self.client.get("/dashboard")
Example userlist.json file: 
[
  {"username": "user1", "password": "pass1"},
  {"username": "user2", "password": "pass2"},
  {"username": "user3", "password": "pass3"}
]

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Reading CSV Data for Test Scenarios

import csv
import random
from locust import HttpUser, task, between

class DataDrivenUser(HttpUser):
    wait_time = between(1, 3)
    
    def on_start(self):
        # Load test data from CSV file
        self.test_data = []
        with open('files/test_data.csv', 'r') as f:
            reader = csv.DictReader(f)
            for row in reader:
                self.test_data.append(row)
    
    @task
    def submit_form(self):
        # Pick a random data row for this request
        data = random.choice(self.test_data)
        
        # Use the data in a POST request
        self.client.post("/api/submit", {
            "name": data['name'],
            "email": data['email'],
            "message": data['message']
        })

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Using a Configuration File

import json
from locust import HttpUser, task, between

class ConfigDrivenUser(HttpUser):
    wait_time = between(1, 5)
    
    def on_start(self):
        # Load configuration from JSON file
        with open('files/config.json', 'r') as f:
            self.config = json.load(f)
        
        # Set up the test based on configuration
        self.api_endpoints = self.config['endpoints']
        self.headers = self.config['headers']
    
    @task
    def call_api(self):
        for endpoint in self.api_endpoints:
            self.client.get(
                endpoint['url'],
                headers=self.headers,
                name=endpoint['name']
            )

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Best Practices

  • File Size: Keep files under 5MB for optimal performance
  • File Format: Use structured formats like JSON or CSV for easy parsing
  • Error Handling: Always include error handling when reading files
  • Caching: Load files once during startup rather than for each request
  • Random Selection: For user credentials, randomly select from a large pool to simulate realistic behavior

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Need Further Assistance?

If you have questions about using files in your load tests or need help with a specific implementation, don’t hesitate to contact us. We’re here to help you get the most out of LoadForge.