WasmFunction is a Kubernetes-native serverless FaaS solution built on top of WebAssembly.

We focuses on:

• Seamlessly using WebAssembly in Kubernetes like OCI Container.
• Reduce Kubernetes container cold start time.
• Build a WebAssembly-based FaaS platform on top of the optimized Kubernetes.

Our solution aims to achieve comparable cold start performance without container pre-warming.

Out solution involves development and optimization of projects and applications at different levels.

• 1999huye1104/wasm-faas. Made some extension and customization from fission/fission, to manage WebAssembly functions.

• WasmFunction/k3s-k8s. Made some optimization about timers and reduced cold start time.

• WasmFunction/containerd. Made some optimization about pod sandbox and status reporting.

• WasmFunction/kuasar. Made some customization for wasm-sandboxer from the kuasar-io/kuasar, to use our external WebAssembly runtime instead.

• WasmFunction/rust-extensions. Stable dependency for WasmFunction/kuasar. fixed and completed metric collecting.

• WasmFunction/wasmkeeper. Customized WebAssembly runtime and also a HTTP server that serves WebAssembly function. Called by WasmFunction/kuasar and runs as the container process.

Test Environment: Ubuntu 24.04 LTS

1. First, download the installation package.

   wget https://github.com/WasmFunction/WasmFunction/releases/download/v0.0.1/wasm-function.tar.gz

2. Run the installation script.

   source install.sh
   # Note
   During the installation of WasmEdge, the script temporarily sets the following environment variables to ensure library files load correctly:
   - `LD_LIBRARY_PATH`: `/usr/local/lib/`
   
   If you want these environment variables to persist in future terminal sessions, you can add them to your `~/.bashrc` file as follows:
   ```bash
   echo 'export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH' >> ~/.bashrc
   source ~/.bashrc

3. Run the startup script.

   source startup.sh
   # Note
   The following environment variables are set in this script, but are only effective in the current shell session:
   - `FISSION_NAMESPACE`: Currently set to `fission`
   - `FISSION_ROUTER`: Currently set to `localhost:32046`
   
   If you want these environment variables to persist across future sessions, you can add them to your `~/.bashrc` file as follows:
   ```bash
   echo 'export FISSION_NAMESPACE=fission' >> ~/.bashrc
   echo 'export FISSION_ROUTER=localhost:32046' >> ~/.bashrc
   source ~/.bashrc

4. Use the following command to check if the Fission components are running and to verify that containerd and Wasm-sandboxer are running in the background using tmux. If any of them are not running, rerun the startup script.

   kubectl get pods
   tmux ls

Test Environment: Ubuntu 24.04 LTS

1. Create the "sort" and "hello" functions (the functions should be packaged into images beforehand).

   fission fn run-kuasar-wasm --name sort --image docker.io/amnesia1997/sortwasm --port 10086
   fission fn run-kuasar-wasm --name hello --image docker.io/amnesia1997/hellowasm --port 10086

2. Create corresponding HTTP triggers.

   fission route create --url /sort --method POST --function sort
   fission route create --url /hello --method POST --function hello

3. Trigger the functions using the following commands.

   curl -X POST -H "Content-Type: application/json" -d '{"args":["1111", "2345", "8", "99", "11234", "12312", "1231231", "-10000"]}' http://$FISSION_ROUTER/sort
   
   curl -X POST -H "Content-Type: application/json" -d '{}' http://$FISSION_ROUTER/hello

You should see the following output.

4. You can check the corresponding resources created in Kubernetes for the two functions under the "fission-function" namespace, and you can also use Fission commands to view the created functions and triggers.

Take sort.cpp as an example (source code generated by GPT-4).

#include <stdio.h>
#include <stdlib.h>

int compare(const void* a, const void* b) {
    return (*(int*)a - *(int*)b);
}

int main(int argc, char** argv) {
    if (argc < 2) {
        printf("No numbers to sort\n");
        return 0;
    }

    int count = argc - 1;
	int* numbers = (int*)malloc(count * sizeof(int));
    for (int i = 1; i < argc; i++) {
        numbers[i - 1] = atoi(argv[i]);
    }

    qsort(numbers, count, sizeof(int), compare);

    for (int i = 0; i < count; i++) {
        printf("%d ", numbers[i]);
    }
    printf("\n");
    free(numbers);
    return 0;
}

You can compile this to a .wasm executable file using various tools, which are not covered here.

curl -X POST -H "Content-Type: application/json" -d '{"args":["1111", "2345", "8", "99", "11234", "12312", "1231231", "-10000"]}' http://$FISSION_ROUTER/sort.

1. When this sort function is triggered via an HTTP request, the args field in the request body contains a list of numbers in string format: {"args":["1111", "2345", "8", "99", "11234", "12312", "1231231", "-10000"]}. These arguments will be parsed as command-line arguments and passed to the WebAssembly runtime. Essentially, it will execute a command like:wasmedge sort.wasm 1111 2345 8 99 11234 12312 1231231 -10000. Note: In the actual C program, argv[0] is "sort.wasm" (the program name), and the arguments "1111", "2345", ... start from argv[1]. Therefore, we need to process the arguments from argv[1] onwards and convert them to integers.
2. Two key points:
   • Command-line argument handling: argv[0] is the program name, and the numbers start from argv[1].
   • Correspondence between the HTTP request body and the program arguments: The string list in the args field is parsed into integers for sorting.
3. Based on the above rules, developers can customize various functions.

The Dockerfile content used to package functions into images is unified as follows.

FROM scratch
COPY YOUR_FUNCTION.WASM /
ENTRYPOINT = ["YOUR_FUNCTION.WASM"]

For example:
FROM scratch
COPY sort.wasm /
ENTRYPOINT = ["sort.wasm"]

This project mainly consists of Fission and K8s components. The K8s components include K3s, containerd, Kuasar, and Wasmkeeper.

This section will explain how to compile in the following order: Wasmkeeper, Kuasar, containerd, K3s, and Fission. By following these steps, you can compile and run the project yourself.

Wasmkeeper is used to create container processes and run WebAssembly instances.

• WasmFunction/wasmkeeper: A simple http server that runs wasm functions. (github.com)

Prerequisites

• cmake

• vcpkg

• wasmedge v0.11.2

  wget https://github.com/WasmEdge/WasmEdge/releases/download/0.11.2/WasmEdge-0.11.2-ubuntu20.04_x86_64.tar.gz
  tar -zxvf WasmEdge-0.11.2-ubuntu20.04_x86_64.tar.gz
  cp -r WasmEdge-0.11.2-Linux/include/* /usr/local/include/
  cp -r WasmEdge-0.11.2-Linux/lib/* /usr/local/lib/
  cp WasmEdge-0.11.2-Linux/bin/wasmedge /usr/local/lib/
  export LD_LIBRARY_PATH=/usr/local/lib/

Build and Install

# install dependency using vcpkg
# cd path/to/vcpkg
./vcpkg install jsoncpp

# clone repository
git clone https://github.com/WasmFunction/wasmkeeper.git
cd wasmkeeper

# cd path/to/wasmkeeper
mkdir build && cd build

# change [vcpkg root] to path/to/vcpkg
cmake .. -DCMAKE_TOOLCHAIN_FILE=[vcpkg root]/scripts/buildsystems/vcpkg.cmake

# compile
cmake --build .

# install
cp wasmkeeper /usr/local/bin/

Wasm-sandboxer is used by containerd to provide sandbox management and task services, responsible for calling Wasmkeeper to create and manage container processes.

• WasmFunction/kuasar: A multi-sandbox container runtime that provides cloud-native, all-scenario multiple sandbox container solutions. (github.com)

Prerequisites

• Rust

Build and Install

# clone repository
git clone https://github.com/WasmFunction/kuasar.git
cd kuasar
# *** important ***
git checkout wasmkeeper

# compile
make bin/wasm-sandboxer

# install
cp bin/wasm-sandboxer /usr/local/bin/

Run

It's recommended to run Wasm-sandboxer in the background using tmux.

tmux new-session -d -s wasm-sandboxer 'wasm-sandboxer --listen /run/wasm-sandboxer.sock --dir /run/kuasar-wasm'

This is a modified version of containerd to support Wasm-sandboxer, and it integrates with Fission to update Pod IPs.

• WasmFunction/containerd at fission_event (github.com)

Prerequisites

• Go

Build and Install

The installation of runc and CNI follows the same steps as in the original containerd. If the following method doesn't work, refer to the official containerd documentation for installation.

• containerd/docs/getting-started.md at main · containerd/containerd (github.com)

1. Install runc to run OCI containers:

   Download the runc.<ARCH> binary from https://github.com/opencontainers/runc/releases , verify its sha256sum, and install it as /usr/local/sbin/runc.

   install -m 755 runc.amd64 /usr/local/sbin/runc

2. Install CNI plugins:

   Download the cni-plugins-<OS>-<ARCH>-<VERSION>.tgz archive from https://github.com/containernetworking/plugins/releases , verify its sha256sum, and extract it under /opt/cni/bin：

   mkdir -p /opt/cni/bin
   
   tar Cxzvf /opt/cni/bin cni-plugins-<OS>-<ARCH>-<VERSION>.tgz

3. Build and install containerd:

   # clone repository
   git clone https://github.com/WasmFunction/containerd.git
   cd containerd
   # *** important ***
   git checkout fission_event
   
   make bin/containerd
   
   cp bin/containerd  /usr/local/bin/

   Copy the Containerd configuration file config.toml.kuasar to the Containerd configuration directory.

   wget https://raw.githubusercontent.com/WasmFunction/WasmFunctionFiles/refs/heads/main/config.toml.kuasar
   mkdir /etc/containerd/
   cp config.toml.kuasar /etc/containerd/config.toml

This configuration file is based on Kuasar's Containerd configuration file, with the CNI plugin configuration replaced by K3s configuration.

Run

It's recommended to run containerd in the background using tmux.

tmux new-session -d -s containerd 'ENABLE_CRI_SANDBOXES=1 containerd'

This is an optimized version of K3s to address timer issues.

• WasmFunction/k3s-k8s: customized kubernetes from k3s (github.com)

Prerequisites

• Go
• Docker

Build and Install

# clone repository
git clone https://github.com/WasmFunction/k3s.git
cd k3s

# config
mkdir -p build/data && make download && make generate

# compile
SKIP_VALIDATE=true make

# install
cp ./dist/artifacts/k3s /usr/local/bin/

Run

Use k3s_install.sh to initialize the k3s service.

Master Node

wget https://raw.githubusercontent.com/WasmFunction/WasmFunctionFiles/refs/heads/main/k3s_install.sh
# init service
INSTALL_K3S_SKIP_DOWNLOAD=true sh ./k3s_install.sh --container-runtime-endpoint /run/containerd/containerd.sock

# kubeconfig set up
mkdir ~/.kube
cp /etc/rancher/k3s/k3s.yaml ~/.kube/config

If the master node does not run Wasm workloads, you can skip installing the above programs.

# init service
INSTALL_K3S_SKIP_DOWNLOAD=true sh ./k3s_install.sh

# kubeconfig set up
mkdir ~/.kube
cp /etc/rancher/k3s/k3s.yaml ~/.kube/config

Worker Node

After initializing the master node, on the master node, retrieve the token

cat /var/lib/rancher/k3s/server/token

Replace [master ip] and [token] with the actual values from the master node and run the following command to join the worker node to the cluster

INSTALL_K3S_SKIP_DOWNLOAD=true K3S_URL=https://[master ip]:6443 K3S_TOKEN=[token] sh ./k3s_install.sh --container-runtime-endpoint /run/containerd/containerd.sock

Please refer to the Fission Compilation and Packaging Process for the build process.

For deployment, you can refer to the official Fission guide to create CRD resources and namespaces, but use the YAML files provided by this project, and the extended Fission CLI provided by this project (which is obtained during Fission compilation).

# Create CRD resources
kubectl create -k "github.com/fission/fission/crds/v1?ref=v1.17.0"

# Set the default namespace to fission
export FISSION_NAMESPACE="fission"
kubectl create namespace $FISSION_NAMESPACE
kubectl config set-context --current --namespace=$FISSION_NAMESPACE

# Fetch the yaml file
wget https://raw.githubusercontent.com/WasmFunction/WasmFunctionFiles/refs/heads/main/wasm-function.yaml

# Install Fission
kubectl apply -f wasm-function.yaml

# Install CLI (if you compiled your own version, modify the URL to point to your CLI release, for example):
curl -Lo faas-cli https://github.com/1999huye1104/wasm-faas/releases/download/v1.18.14/fission-v1.18.14-linux-amd64 && chmod +x faas-cli && sudo mv fission /usr/local/bin/

• https://www.infracloud.io/serverless-functions-kubernetes/
• https://knative.dev/docs/
• https://openwhisk.apache.org/
• https://www.openfaas.com/pricing/
• https://cn.serverless.com/
• https://kuasar.io/