registry/example

Services advertisement and discovery

Overview

This example shows how to use Registry to discover and call fluence services without having their exact peer and service ids.

Table of contents:

• Services advertisement and discovery
  • Overview
  • Table of contents:
  • Set up the environment
  • Deploy echo service written in Rust
  • Run echo service written in JS/TS
  • Register both services using Registry
  • Call both services using resourceId
  • Remove service record

Set up the environment

1. Install the latest version of Fluence CLI
2. Install Fluence project dependencies. It may take a while:

   fluence dep i
   

3. Install JS dependencies:

   npm i
   

You can also use VSCode with Aqua extension for Aqua language syntax highlighting and better developer experience.

Deploy echo service written in Rust

To deploy the Fluence application execute

fluence deploy

Press Enter when prompted ? Do you want to deploy all of these services? (Y/n)

This Fluence application, described in fluence.yaml, consists of just one echo service which has only one module written in Rust. The module code has only one function echo, which returns your msg along with peerId of the host:

To call echo aqua function execute:

fluence run -f 'echo("hi")'

The function uses peerId and serviceId, which Fluence CLI stored in ./.fluence/app.yaml when you deployed the Fluence application in the previous step.

You should see output similar to this:

"12D3KooWFEwNWcHqi9rtsmDhsYcDbRUCDXH84RC4FW6UfsFWaoHi: hi"

It means we successfully deployed our echo service, and anyone can call it if they have peerId and serviceId

Run echo service written in JS/TS

Execute

npm run start

First, aqua code in src/aqua/export.aqua will be compiled to typescript and you will see it in src/generated/export.ts.

Then you possibly will have to confirm ts-node installation and src/echo.ts will be executed. It registers local js service with serviceId "echo", so anyone who has relayId, peerId and serviceId ("echo") will be able to call it. Copy the command from the terminal, which will look similar to this:

fluence run -f 'echoJS("12D3KooWCmnhnGvKTqEXpVLzdrYu3TkQ3HcLyArGJpLPooJQ69dN", "12D3KooWSD5PToNiLQwKDXsu8JSysCwUt8BVUJEqCHcDe7P5h45e", "echo", "hi")'

This command executes echoJS aqua function with arguments: relayId, peerId, serviceId and msg

Open another terminal in the same directory, paste the command and run it.

You should see output similar to this:

"12D3KooWCmnhnGvKTqEXpVLzdrYu3TkQ3HcLyArGJpLPooJQ69dN: hi"

It means anyone can call our echo service, written in TS/JS, if they have relayId, peerId and serviceId.

Register both services using Registry

We can register our services in Registry if we want anyone to be able to call our services without specifying the exact relay, peer, and service IDs.

First, we need to create the Resource. The Resource represents a group of services and has a corresponding resourceId which we can use for service discovery.

To call createRes aqua function, execute

fluence run -f 'createRes()'

It uses createResource function from Resources API to register the Resource with the label echo. You should see output similar to this:

[
  "5pYpWB3ozi6fi1EjNs9X5kE156aA6iLECxTuVdJgUaLB"
]

It is resourceId, which we will use to register our services, and then we will be able to use the same resourceId to discover and call our services

To register the echo service written in Rust, replace RESOURCE_ID and execute

fluence run -f 'registerEchoService("RESOURCE_ID")'

This command calls registerEchoService aqua function, which uses registerService function from Resources API to register the rust service on this resourceId

You should see this output:

[
  [
    true
  ]
]

It means the service is registered in Registry and should be accessible by anyone who only has the resourceId of this service.

Then please stop fluence js peer in the previous terminal that you ran.

To register echo service written in JS/TS on the Resource, replace RESOURCE_ID and execute

npm run start -- 'RESOURCE_ID'

Call both services using resourceId

Go to a different terminal in the same directory, replace RESOURCE_ID and execute this command to call echoAll aqua function

fluence run -f 'echoAll("RESOURCE_ID", "hi")'

It uses resourceId to resolve a minimum of two records with peer and service ids and then uses them to call our services

You should see output similar to this:

[
  [
    "12D3KooWFEwNWcHqi9rtsmDhsYcDbRUCDXH84RC4FW6UfsFWaoHi: hi",
    "12D3KooWCmnhnGvKTqEXpVLzdrYu3TkQ3HcLyArGJpLPooJQ69dN: hi"
  ]
]

It means we successfully registered our services using Registry, and now anyone can call these services using only resourceId.

Remove service record

Replace RESOURCE_ID and execute

fluence run -f 'unregisterEchoService("RESOURCE_ID")'

to call unregisterEchoService function that uses unregisterService function from Resources API to unregister only our echo services written in Rust

The output should look like this:

[
  [
    true
  ]
]

Let's make sure we've removed the service record. Once again, replace RESOURCE_ID and execute

fluence run -f 'echoAll("RESOURCE_ID", "hi")'

You should see output similar to this:

[
  [
    "12D3KooWCmnhnGvKTqEXpVLzdrYu3TkQ3HcLyArGJpLPooJQ69dN: hi"
  ]
]

You can notice that only one result is left instead of two. It means we successfully removed the service record from our Resource