Generate and start the VDK Service

Overview

This guide empowers you to create and manage voice applications using VDK Service, an extension of the Voice Development Kit (VDK). VDK Service simplifies the development and deployment process for voice-driven experiences.

Create and export a project with the VDK Service interaction mode

To generate the vdk-service we need to follow these steps:

Create a project:
Initiate a new custom project and specify the 'VDK Service' interaction mode during project setup.
Integrate technologies:
Integrate the desired technologies into your project and configure them accordingly.
Export your project:
Export your project to the designated target folder. This will generate three directories: 'config,' 'data,' and 'vdk-service'.
BASH
```
$ tree -d -L 1
.
|-- config
|-- data
`-- vdk-service
3 directories
```

Starting the VDK Service

Windows/Linux

Use the command below to start the service:

BASH

$ ./vdk-service/bin/vdk-service.exe -f config/vsdk.json

Where the parameter -f is used to specify the configuration file location. If you want to load the configuration file later, start by launching the service without specifying the configuration file and later use the route localhost:39806/v1/configuration-path to load the configuration file.

BASH

$ ./vdk-service/bin/vdk-service.exe &
$ curl --header "Content-Type: application/json" \
  --request POST \
  --data '{"path":"config/vsdk.json"}' \
  http://localhost:39806/v1/configuration-path

Android

First of all, move the data exported from the VDK Studio into your Android project:

assets and jniLibs to app/src/main/

Then, you will need to configure the network access into your Android Manifest.

First, add the permission below to AndroidManifest.xml:

<uses-permission android:name="android.permission.INTERNET" />

Then, we will need to configure the network security. Create a file into res/xml named network_security_config.xml and paste the content below in it:

CODE

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">127.0.0.1</domain>
    </domain-config>
</network-security-config>

Finally, add to tag <application> into the Manifest: `

CODE

android:networkSecurityConfig="@xml/network_security_config"

It will allow the vdk-service to use spawn a HTTP webserver.

Now that everything is configured, create the VdkServiceNative class that you can use it to start and stop the vdk-service (Make sure to keep the same package name and class name):

Kotlin:

KOTLIN

package com.vivoka.vdk

class Service {
    init {
        System.loadLibrary("vdk-service-jni")
    }

    external fun start(configPath: String, port: Int): Int
    external fun stop()
}

Java:

JAVA

package com.vivoka.vdk;

class Service {
    static {
        System.loadLibrary("vsdk-service-jni");
    }

    public native int start(String configPath, int port);
    public native void stop();
}

Call start to Start your service:

JAVA

final String configPath = getFilesDir().getAbsolutePath() + "/vsdk/config/vsdk.json";
com.vivoka.vdk.Service.start(configPath, 39666);

The vdk-service should now run and start a webserver listening on 127.0.0.1:39666.

For more details you can refer to vdk-android-samples-service-application sample.

The configuration path can be loaded just once either with terminal argument or with REST api route.

Different starting options:

Option	Value range	Default value	Description
`-h`, `--help`	-	-	Prints usage then exits
`-p`, `--port`	[1-65535]	`39806`	Port the web server will listen to (HTTP & WebSocket).
`-c`, `--cpu-count`	[0, 2-255]	`0`	Number of logical cores used (0 means hardware count).
`-d`, `--websocket-close-delay`	[0-65535]	`0`	Amount of milliseconds spent before closing a websocket.
`-f`, `--config-path`	-	`""`	Path to a VSDK configuration file to starts with.
`-L`, `--plugin-path`	-	`../plugins/`	Path to the dynamic libraries.
`-v`, `--verbosity`	[off, trace, debug, info, warning, error, critical]	`debug`	Minimum log level that can be printed.
`-V`, `--version`	-	-	Output version information and exit.

Stopping the VDK Service (Safely)

Two methods are available for safe termination of the VDK service:

Using quit route

BASH

$ curl --header "Content-Type: application/json" \
  --request POST \
  --data '{}' \
  http://localhost:39806/v1/quit

Sending SIGINT or SIGTERM to the application.
This method involves sending the appropriate signal to the application process.