https://github.com/thorstenhans/krustlet-at-rust-linz
https://github.com/thorstenhans/krustlet-at-rust-linz
Last synced: about 1 month ago
JSON representation
- Host: GitHub
- URL: https://github.com/thorstenhans/krustlet-at-rust-linz
- Owner: ThorstenHans
- Created: 2021-11-25T18:38:00.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2021-11-25T18:38:22.000Z (over 3 years ago)
- Last Synced: 2025-02-15T10:17:38.381Z (3 months ago)
- Language: Rust
- Size: 3.91 KB
- Stars: 3
- Watchers: 3
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# A quick look at krustlet
This repo contains fundamental WebAssembly (Wasm) workloads that could be executed on [krustlet](https://krustlet.dev).
## Setup
- obviously, you must have a krustlet running. You can add krustlet to different Kubernetes distributions and managed Kubernetes services.
- an OCI distribution spec compliant Container Registry (e.g. Azure Container Registry) is required. We will use it as distribution channel for our Wasm workloads
- `wasm32-wasi` must be installed as target (`rustup target add wasm32-wasi`)
- Workloads must be compiled against the `wasm32-wasi` using `cargo build --release --target wasm32-wasi`
## Container Registry Authentication
Authentication information for the container registry must be persisted in the desired Kubernetes Namespace. You can use the following snippet to persist such an authentication information:
```bash
regLoginServer=foo.azurecr.io
regUser=bob
regPassword=bob
k8sNamespace=default
kubectl create secret docker-registry acr \
--docker-username $regUser \
--docker-server $regLoginServer \
--docker-password $regPassword
--namespace $k8sNamespace
```
## Verify krustlet taints
Depending on your environment you may find different `taints` being assigned to the krustlet nodes. Verify if your taints are `wasm32-wasi` or `wasm32-wagi`:
```bash
# get all nodes in your cluster
kubectl get nodes
NAME STATUS ROLES AGE VERSION
kind-control-plane Ready control-plane,master 103m v1.21.1
foobar Ready 39m 1.0.0-alpha.1
# get node taints
kubectl describe node foobar
# omitted
Taints: kubernetes.io/arch=wasm32-wasi:NoExecute
kubernetes.io/arch=wasm32-wasi:NoSchedule
# omitted
```
Note down the `arch`, you must specify it as part of the Pods `tolerations` (see `pod.yml` in both samples -> `podSpec.tolerations`)
## Publishing Wasm modules to Azure Container Registry (ACR)
Assuming having access to an ACR instance called `foobar`, we must push both Wasm modules (`hello-krustlet` and `hello-wasi`) to the ACR instance. To do so, we use [wasm-to-oci](https://github.com/engineerd/wasm-to-oci)
```bash
# authenticate against ACR (either use Azure CLI or use Docker CLI)
az acr login -n foobar
cd hello-krustlet
cargo build --release --target wasm32-wasi
wasm-to-oci ./target/wasm32-wasi/release/hello-krustlet.wasm foobar.azurecr.io/hello-krustlet:0.0.1
cd ..
cd hello-wasi
cargo build --release --target wasm32-wasi
wasm-to-oci ./target/wasm32-wasi/release/hello-wasi.wasm foobar.azurecr.io/hello-wasi:0.0.1
```
## Running hello-krustlet
You can run `hello-krustlet` by applying the Kubernetes manifest located in the kubernetes subfolder:
```bash
kubectl apply -f ./hello-krustlet/kubernetes/pod.yml
```
## Running hello-krustlet
You can run `hello-krustlet` locally using any (non-browser) WASM runtime. The following sample uses `wasmtime`:
```bash
cd hello-krustlet
cargo build --release --target wasm32-wasi
wasmtime run ./target/wasm32-wasi/release/hello-krustlet.wasm
```
## Running hello-wasi in KIND
Before running `hello-wasi`, you must configure the persistent volume used in the pod spec `podSpec.volumes[0]`.
The WASI sample will issue a system call (create a file). You must allow the module to write to the desired location (`/mnt/data` -> see `podSpec.containers[0].env` and `podSpec.containers[0].volumeMounts[0]`)
You can run `hello-krustlet` by applying the Kubernetes manifest located in the kubernetes subfolder:
```bash
kubectl apply -f ./hello-krustlet/kubernetes/pod.yml
```
## Running hello-wasi locally
You can run `hello-wasi` locally using any (non-browser) WASM runtime. The following sample uses `wasmtime`:
```bash
cd hello-wasi
cargo build --release --target wasm32-wasi
wasmtime run --env TARGET=/Users/bob/Downloads --dir /Users/bob/Downloads ./target/wasm32-wasi/release/hello-wasi.wasm
```