In this section:

Overview

The Parasoft gRPC Listener Extension adds support for the Google Remote Procedure Call message format so that Virtualize assets can read a single message from a topic and respond with a single message on another topic.

Requirements

gRPC 1.0.0 or later
Parasoft Virtualize 2020.2 or later

Installation

This artifact can be installed from the UI or the command line.

UI Installation

Choose Parasoft > Preferences.
In the System Properties preferences page, click Add JARs.
In the file chooser that opens, select com.parasoft.virtualize.listener.grpc-<version>.jar.
Click Apply and restart Virtualize.

Command Line Installation

Add the com.parasoft.soavirt.listener.grpc-<version>.jar file to the system.properties.classpath property in your settings properties file. For example:

system.properties.classpath=<path to jar>/com.parasoft.soavirt.transport.grpc-1.0.jar

Usage

After installation, the gRPC Listener option will appear in the Virtual Asset Deployment Settings. The gRPC implementation can be used for all responders except SQL Responders.

Open the virtual asset settings and click the Transport tab.
Click the Custom tab and configure the listener settings (see Configuration). If your system has more than one custom extension, choose gRPC Lister from the Select Implementation drop-down menu.

SOAtest 2022.1 > gRPC Listener > virt-grpc-listener-format-pva-20221.png

Configuration

There are four groups of settings to configure: Connection, Injected Headers, Transport Layer Security, and Logging. Each group is described below.

Connection Settings

Listen Port	Specify the port Virtualize should open for receiving incoming gRPC calls. Virtualize will select an open port automatically when set to `0`. Value must be between `0` and `65535`. If this field is left blank, this virtual asset will not listen for gRPC calls.
Service Name	Specify the gRPC service name that corresponds with this virtual asset.
Method Names	Specify the gRPC methods for the above service to be handled by this virtual asset. Separate multiple entries with commas.
Method Types	Specify the method type or types, for example `unary` or `stream`. Separate multiple entries with commas. The default is `unary`.

Injected Headers Settings

Method Header	Specify the method header. The default is `gRPC-Method`.
Call ID Header	Specify the call ID header. The default is `gRPC-Call-ID`.
Notification Header	Specify the notification header. The default is `gRPC-Notification`.

Transport Layer Security Settings

Auth Mechanism Specify the authorization mechanism you want to use to connect to the gRPC server. Options are SSL and insecure. The default is insecure.

Certificate Chain File

Specify the path to the certificate chain file in PEM format.

This field is ignored when the Auth Mechanism is set to insecure.

Private Key File

Specify the path to the private key file in PEM format.

This field is ignored when the Auth Mechanism is set to insecure.

Logging Settings

Log Level	Specify how much information you want logged to the console. The default is `2` (warn).

Virtualizing Different gRPC Services

Each virtual asset represents one gRPC service with one or more methods. Deploy multiple virtual assets on the same gRPC port to represent multiple gRPC services on the same gRPC server.

Virtualizing Different gRPC Methods

A gRPC method may operate as one of four types:

Unary
Server streaming
Client streaming
Bidirectional streaming

Unary Method

Virtualize uses a single message responder to emulate one call to a unary gRPC method. This is the default mode for methods in the gRPC custom listener. The client request is handled by the responder if the correlation criteria matches, then the responder returns the response to the gRPC client. Set a transport header correlation of gRPC-Method to match the message responder to the gRPC method name.

SOAtest 2022.1 > gRPC Listener > unary-method-example.png

Streaming Methods

Multiple message responders are needed to emulate the streaming gRPC method types. In each case the client requests and server responses can be decoupled. Set a transport header correlation of gRPC-Notification to trigger the responder at the appropriate point in the stream. Supported values are: next, completed, and error.

SOAtest 2022.1 > gRPC Listener > streaming-method-example-1.png

Set the message responder options for Message Exchange Pattern to Notification Only if the responder for this point in the stream should not send any response message back.

SOAtest 2022.1 > gRPC Listener > streaming-method-example-2.png

In order to send multiple response messages together on the steam, or send an error or completed notification, you will need to chain a messaging client to the request payload output of the message responder and map it to the same Call ID that is being handled by the responder. To do so:

Right-click the responder and go to Add Output... > Incoming Request > Transport Header, then select Header Data Bank.
Click Add Header, then select the header that's added and click Modify to add a header extraction for gRPC-Call-ID to a custom column. Click OK when you're done.
Right-click the responder again and go to Add Output... > Incoming Request > Payload, then select Messaging Client. Configure the transport of the messaging client to use gRPC with the parameterized CALL_ID in the streaming section.

The chained messaging client will send on the response stream for the virtualized gRPC call back to the client.

SOAtest 2022.1 > gRPC Listener > sample-tree.png

Third-party Content

This extension includes items that have been sourced from third parties as outlined below.

Additional license details are available in this plugin's licenses folder.