Creating and Configuring Your First FX Service

Creating and Configuring Your First FX Service in a Local Environment

This guide provides a clear walkthrough of the process for creating and simulating services, all within the comfort of your desktop IDE. By following these steps, you’ll be able to seamlessly generate and define services, and then simulate their behavior before taking them live.

Step 1: Create a Virtual Environment

Before you start working on your FX service, it’s a good practice to create a virtual environment to isolate your project’s dependencies. A virtual environment ensures that the packages you install for this project won’t conflict with packages from other projects. You can create a virtual environment using a tool like virtualenv:

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# Replace "my_fx_project" with your desired project name
virtualenv my_fx_project-env

Activate the virtual environment:

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source my_fx_project-env/bin/activate

Step 2: Set Environment Variable

Set the EF_ENV environment variable to “local” to indicate that you’re working in a local development environment:

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export EF_ENV=local

Step 3: Project Directory Setup

Create a directory that will serve as the main project directory. Inside this directory, you will organize multiple services. For example:

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mkdir my_fx_project
cd my_fx_project

Step 4: Create Service Directory

Within the project directory, create a subdirectory for your specific service. This directory should have a name that consists of alphanumeric characters in lowercase, along with underscores (_) and hyphens (-), no spaces allowed:

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mkdir my-service-name
cd my-service-name

Step 5: Create app.py

Inside the service directory, create an app.py file. This file will serve as the entry point for your FX service. In this file, import the necessary context from the fx_ef (core library) for your service:

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# app.py
from fx_ef import context

# Your service code starts here

Step 6: Run app.py

Run the app.py file. This step generates two JSON files:

• ef_env.json: Simulates the parameters, secrets, and configurations of the service.
• ef_package_state.json: Holds the execution state of the service.

The above two files are used to simulate the service environment and are not used at runtime. They should not be checked in to git. A sample .gitignore for FX projects is provided here The GitIgnore File

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python app.py

Step 7: Expand Your Service

With the initial setup done, you can now expand the app.py file with your actual service logic. Build and implement your FX service within this file.

Step 8: Module Placement

It’s important to note that any modules (additional Python files) your service relies on should be placed within the same directory as the app.py file. FX does not support nested directories for modules.

By following these steps, you’ll be able to create your first FX service in a local environment, set up the necessary configurations, and start building your service logic. Remember to activate your virtual environment whenever you work on this project and customize the app.py file to match the functionality you want your FX service to provide.

Adding a manifest.json file to describe your FX service to the platform is an essential step for proper integration and communication. Here’s how you can create and structure the manifest.json file:

Step 9: Create manifest.json

Inside your service directory, create a manifest.json file. This JSON file will contain metadata about your service, allowing the FX platform to understand and interact with it.

The manifest.json file provides vital information about your FX service, making it easier for the platform to understand and manage your service’s behavior and dependencies.

By including this file and its necessary attributes, your service can be properly registered, tracked, and executed within the FX platform. This manifest file essentially acts as a contract between your service and the platform, enabling seamless integration.

Understanding manifest.json: Defining Your Service

The manifest.json file plays a critical role in describing your application to the FX Platform, as well as to fellow users and developers. Below is a sample manifest.json file along with an explanation of its parameters:

manifest.json Example:

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{
  "description": "Service with manifest file",
  "entrypoint": "app.py",
  "execution_order": ["app_1.py", "app.py"],
  "tags": ["devops"],
  "trigger_events": ["ferris.apps.minio.file_uploaded"],
  "schedule": "54 * * * *",
  "allow_manual_triggering": true,
  "active": true,
  "output_events": ["test_type_101", "test_type_112"]
}

Parameters and Descriptions:

This manifest.json file provides essential metadata about your service, making it easier for both the platform and other users to understand its purpose, behavior, and triggers. By customizing these parameters, you tailor the service’s behavior to your specific requirements.

The output_events attribute has no impact on the service at run time. But it helps display on the UI the downstream services that are connected to this service and thereby helps other developers who wish to connect to this service.

Step 10: Expand ef_env.json

The ef_env.json file plays a critical role in simulating your service’s environment during development. While on the FX platform, parameters, configs, and secrets are managed differently, in the local environment, you can define these elements within this JSON file for simulation purposes.

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{
  "parameters": {
    "param1": "value1",
    "param2": "value2"
  },
  "secrets": {
    "secret_key1": "secret_value1",
    "secret_key2": "secret_value2"
  },
  "configs": {
    "config_key1": "config_value1",
    "config_key2": "config_value2"
  }
}

• "parameters": In the local environment, you can define parameters directly within this dictionary. These parameters are typically accessed within your service code using the fx_ef library.

• "secrets": Similarly, you can define secret values in this section. While on the platform, secrets will be managed through the UI and loaded into your service securely. During local simulation, you can include sample secret values for testing.

• "configs": For configuration values, you can specify them in this dictionary. However, on the FX platform, configuration values are usually managed through an external config.json file. This is done to keep sensitive configuration data separate from your codebase.

Keep in mind that the ef_env.json file is only for simulation purposes. On the FX platform, parameters are passed through trigger event payloads, configurations come from the config.json file, and secrets are managed through the platform’s UI.

By expanding your ef_env.json file with the appropriate parameters, secrets, and sample configuration values, you’ll be able to effectively simulate your service’s behavior in a local environment. This allows you to test and refine your service logic before deploying it on the FX platform, where parameters, secrets, and configurations are handled differently.

Step 11: Exploring the fx_ef Library

In the following section, we’ll delve into the capabilities of the fx_ef library. This library serves as a bridge between your FX service and the platform, allowing you to seamlessly implement various platform features within your service’s logic.

The fx_ef library encapsulates essential functionalities that enable your service to interact with the FX platform, handling triggers, events, and more. By leveraging these features, you can create robust and responsive FX services that seamlessly integrate with the platform’s ecosystem.

Here’s a sneak peek at some of the functionalities offered by the fx_ef library:

1. Event Handling: The library facilitates event-driven architecture, allowing your service to react to various triggers from the platform. Whether it’s an incoming data event or an external signal, the library provides the tools to manage and respond to events effectively.

2. Parameter Access: While on the FX platform, parameters are passed through trigger event payloads. The library offers methods to access these parameters effortlessly, enabling your service to make decisions and take actions based on the provided inputs.

3. Configuration Management: Although configuration values are typically managed through a separate config.json file on the platform, the fx_ef library simplifies the process of accessing these configurations from within your service code.

4. Secrets Handling: On the platform, secrets are managed securely through the UI. The library ensures that your service can access these secrets securely when running on the platform.

5. Service State Tracking: The library also assists in managing your service’s execution state, tracking its progress and ensuring smooth operation.

By tapping into the capabilities of the fx_ef library, you can build powerful and versatile FX services that seamlessly integrate with the FX platform’s functionalities. In the next section, we’ll dive deeper into the specifics of how to utilize these features in your service logic.

Stay tuned as we explore the fx_ef library in depth, unraveling the tools at your disposal for creating impactful and responsive FX services.