Demo and tutorials

Live Demo | Tutorial article | Tutorial video

1. Introduction

DAPR is a portable, event-driven runtime that makes it easy for any developer to build resilient, stateless and stateful applications that run on the cloud and edge and embraces the diversity of languages and developer frameworks. It's a Microsoft-incubated open-source project.

WasmEdge is a open-source, high-performance, extensible, and hardware optimized WebAssembly Virtual Machine for automotive, cloud, AI, and blockchain applications.

In this demonstration App, we create two image processing web services, integrated with Dapr. This project is built to demonstrate how to use Dapr to integrate Web applications in any programming language, and how WasmEdge can be embed in Go and Rust applications.

2. Architecture

This project contains 4 Dapr sidecar services:

• The Web port service

It is a simple Go Web application which is exposed as an endpoint of the whole application. It will render a static HTML page for the user to upload an image, and receive the image from the user, redirect request to internal image APIs.

• The image service in WasmEdge

This Dapr service is written in Rust and compiled to WebAssembly. Running inside WasmEdge Runtime, the WebAssembly bytecode program creates a HTTP service that listens for RPC requests from other Dapr applications, including the web port.

• The image service in Golang

This Dapr service is written in Golang. It uses WASI to call a prebuild wasm file to classify an image using a Tensorflow model.

• The image service in Rust

This Dapr service is written in Rust. It simply starts a new process for the WasmEdge VM to run and perform grayscale on a image.

3. Prerequisites

• Install Golang Note Package managers like apt will only install older versions of go i.e. go 1.13.8, so please use link above to install go version 1.17.1 or higher.
• install Rust
• Install Dapr
• Install WasmEdge

4. Build

make pre-install  ## Install WasmEdge dependences
make build        ## Will build all the components

## If you modify the wasm functions project,
## Use the commands in ./functions/grayscale/build.sh 
## and ./functions/classify/build.sh to generate new compiled files
make build-wasm

5. Run

To simplify the deployment, we provide a script to run the services:

make run-api-wasi-socket-rs ## Run the WasmEdge microservice
make run-api-go ## Run the image-api-go microservice
make run-api-rs ## Run the image-api-rs microservice
make run-web ## Run the Web port service

For each component, you can also run it individually:

Start the web-port service

cd web-port
dapr run --app-id go-web-port \
         --app-protocol http \
         --app-port 8080 \
         --dapr-http-port 3500 \
         --components-path ../config \
         --log-level debug \
         ./web-port

Start the WasmEdge microservice for image processing

cd image-api-wasi-socket-rs
dapr run --app-id image-api-wasi-socket-rs \
         --app-protocol http \
         --app-port 9005 \
         --dapr-http-port 3503 \
         --components-path ../config \
         --log-level debug \
	 wasmedge ./target/wasm32-wasi/debug/image-api-wasi-socket-rs.wasm

cd image-api-go
dapr run --app-id image-api-go \
         --app-protocol http \
         --app-port 9003 \
         --dapr-http-port 3501 \
         --log-level debug \
         --components-path ../config \
         ./image-api-go

Start the image-api-rust service

cd image-api-rs
dapr run --app-id image-api-rs \
         --app-protocol http \
         --app-port 9004 \
         --dapr-http-port 3502 \
         --components-path ../config \
         --log-level debug \
         ./target/debug/image-api-rs

After all the services started, we can use this command to verify:

dapr list

  APP ID                     HTTP PORT  GRPC PORT  APP PORT  COMMAND               AGE  CREATED              PID
  go-web-port                3500       44483      8080      ./web-port            15m  2021-10-23 12:19.59  270961
  image-api-wasi-socket-rs   3503       41775      9005      wasmedge              9m   2021-10-23 12:25:27  294758
  image-api-rs               3502       41661      9004      ./target/release/...  9m   2021-10-23 12:25.27  285749
  image-api-go               3501       34291      9003      ./image-api-go        9m   2021-10-23 12:25.27  285852

6. Online Demo: Dapr-WasmEdge

Access the demo here