WasmCon NA 2024 - Choose your own adventure

Getting Started

This workshop will walkthrough building a WebAssembly component with WASIP2, how to assemble (compose) a declarative application, and finally deploy (run) across diverse environments.

Chapter 1: Build

WebAssembly (Wasm) components are a portable, language agnostic, and sandbox-able compilation target.

Many language toolchains support building WebAssembly component AKA a .wasm where the first bytes of the binary are (component), by setting wasm32-wasip2 as the target.

Some language toolchains benefit from an SDK geared towards producing components like componentize-py and componentize-dotnet. For this workshop, we will focus on Go with the TinyGo compiler and Rust.

Once you have built a Wasm component, it is portable to any runtime that supports components with wasip2. The WebAssembly runtime that we will use is wasmtime from the Bytecode Alliance foundation.

The application platform that we will use to run our Wasm applications is CNCF wasmCloud.

wasmCloud has a CLI called wash(wasmCloud shell) that simplifies the build, develop, and distribute loop of Wasm components. Install wash now. Note that all of the Wasm components that we will build can also be built with direct tooling. That will take more flags and commands than wash build.

Install wash

Follow the install instructions for installing wash for your system.

Now you must make your first major decision of this journey. What type of application will you create and for which language?

What language will you use?

export WASMCON_LANG="go"

export WASMCON_LANG="rust"

WASMCON_APP="password-checker"
wash new component --git ricochet/wasmcon-na-2024 --subfolder ${WASMCON_LANG}/${WASMCON_APP}

Decide which application to create:

WASMCON_APP="dog-fetcher"

Or

WASMCON_APP="password-checker"

Go with TinyGo

wash new component --git ricochet/wasmcon-na-2024 --subfolder go/dog-fetcher
cd component
wash dev

Checkout the cutest dogs on the planet by continuing to download random dogs. Who will get Fallout's dogmeat?

curl localhost:8000

or

wash new component --git ricochet/wasmcon-na-2024 --subfolder go/password-checker
cd component
./setup.sh # little pre-populate 
wash dev

For password-checker, check out the possible inputs:

curl localhost:8000/api/v1/check -d '{"value": "wasmconisawesome"}'
{"valid":true,"length":16}

curl localhost:8000/api/v1/check -d '{"value": "veryshort"}'
{"valid":false,"message":"insecure password, try including more special characters, using uppercase letters, using numbers or using a longer password"}

curl localhost:8000/api/v1/check -d '{"value": "1234"}'
{"valid":false,"message":"password is in the list of 500 worst passwords"}

For the curious, this is the equivalent command to build a go component:

go generate
tinygo build --target=wasip2 --wit-package ./wit --wit-world password-checker

Rust

wash new component --git ricochet/wasmcon-na-2024 --subfolder rust/dog-fetcher
cd component
wash dev

wash new component --git ricochet/wasmcon-na-2024 --subfolder rust/password-checker
cd component
wash dev

Test

Were you successful?

curl localhost:8000

How large is your binary?

du -h build/component.wasm

Let's get WIT-ty

wasm-tools component wit build/component.wasm

Extend

Let's see what it's like to add a new dependency.

Search for and uncomment the code for PART 2:

1. First uncomment blobstore in the world.wit
2. Then uncomment all of the PART 2: sources

# fetch new WIT deps
# both `wash dev` and `wash build` call `wash wit deps`
# to populate deps based on world.wit
wash build

# P.S. to manually do this with Bytecode Alliance tooling, run:
# wkg wit fetch

# regenerate bindings if necessary
# go generate
# rebuild

wash build detected a change in the world definition and automatically fetched WIT dependencies.

Chapter 2: Compose

Applications are composed of components and optionally stateful providers.

In cloud native nomenclature, an application is the combination of microservices and necessary services like stateful storage and hardware enabled capabilities to run your app. Components are equivalent to stateless 12-factor apps. A provider is a type of host plugin that is used to extend the host to stateful services. Providers can be builtin to the host or run remotely.

You might be wondering, why would I need an application platform if wasmtime (with plugins) should be able to run my component? For the same reason we need kubernetes to orchestrate containers at scale, we gain many benefits of Wasm native orchestration. WebAssembly components are a fundamentally new unit of compute whose benefits are best realized via native orchestration.

Components offer a fundamentally finer-grained abstraction than containers, like Kubernetes for WebAssembly, so wasmCloud provides a Wasm-native orchestrator to best take advantage of the unique properties that WebAssembly components can provide. Wasm-native works with cloud-native and runs seamlessly on Kubernetes or any other container execution engine like AWS Fargate, Microsoft AKS, or Google Cloud Run.

wasmtime is like the kubelet, and wasmCloud is the entire platform like kubernetes including a scheduler and runtime abstraction.

Unlike microservices where we need to layer on API Gateways and service meshes to understand the API provided by a microservice, with components, they are themselves declarative and introspectable.

Remember where we looked at and modified the WIT? Let's take that a step further by linking our component interface with other interfaces declaratively.

The declarative application manifest that is scheduled by wadm.

This is the stage where we most often operate. Writing applications has never been the problem. Maintaining them is the real challenge in software development today.

Today we have platform engineering teams that provide core platform services, think databases, authentication, observability services, etc. The tension between getting teams to upgrade their dependencies and being able to use the latest features of a platform, can now be decoupled from the component that contains only business logic, and the platform services who may now update at runtime.

We've been running with the filesystem. That's really convenient for local development but that's not what we should use for reliability, scalability, and distributability. Blob storage is great at this! Let's use it.

This compose step is the bridge between developer teams and platform engineering.

Let's create a declarative manifest from our dev loop:

wash dev --manifest-output-dir .

wash up -d

Now modify that manifest to use blobstore-s3!

If you're running locally on a mac right now, you can use an S3 compatible blobstore like MinIO.

brew install minio/stable/minio
minio server start

Or with docker:

docker run -d -p 9000:9000 -p 9001:9001 minio/minio server /data --console-address ":9001"

Add the following configuration to the link created (originally) for blobstore-fs.

target:
  name: dep-blobstore-fs
  config:
    - name: wasi-blobstore-config
      properties:
        config_json: '{"endpoint": "http://127.0.0.1:9000", "access_key_id": "minioadmin", "secret_access_key": "minioadmin", "region": "local"}'

# rename generated wadm name to wadm.yaml
wash app deploy wadm.yaml

Chapter 3: Run

This part is often scary for developers. Running reliably at scale in environments that are very different from local development machines, developers are used to experiencing significant friction to deploy into environments with controls.

With CNCF wasmCloud, whether the deployment is running on your local machine, in the cloud, or on the edge, the experience for developers and platform engineers is the same.

Let's pretend for a second that your laptop is a kind of edge.

wash up -d
wash app deploy wadm.yaml

Let's scale out the apps to another host.

wash up -d

wash ui

curl localhost:8080

We need to get rid of the local file if we want to deploy remotely. Let's push our .wasm as an OCI artifact to GHCR.

wash push ghcr.io/ricochet/components/${WASMCON_APP}-${WASMCON_LANG}:0.2.0 build/*_s.wasm

# P.S. BA tooling for this is wkg

Do we need to care what language this app was written in? Nope. It's portable. But is it cloud native? Let's find out.

Shutdown local hosts.

wash down --all

Modify local file path to use your OCI ref.

wash app deploy wadm.yaml

Deploying to Kubernetes

If you have access to another k8s cluster, deploy the wasmCloud platform helm chart.

First things first, cd k8s.

For running k8s locally, use kind.

./scripts/setup-kind.sh

wash app deploy wadm.yaml
# or
kubectl app deploy wadm.yaml

Your princess is in another cluster

# start another kind cluster
# deploy to that cluster as well

Users are on the edge

Change the label to the host on my lattice to my edge host.

wash app deploy wadm.yaml

Noticing a trend? The experience is the same. Unify software development lifecycle steps of build, compose, and run.

With a unified control plane, it is now possible to spread compute across clouds, regions, and edges including your own.