Wasm image in your image store.

   ```console
   $ docker image ls
   REPOSITORY   TAG       IMAGE ID       CREATED         SIZE
   server       latest    2c798ddecfa1   2 minutes ago   3MB
   ```

   Inspecting the image shows the image has a `wasi/wasm` platform, a
   combination of OS and architecture:

   ```console
   $ docker image inspect server | grep -A 3 "Architecture"
           "Architecture": "wasm",
           "Os": "wasi",
           "Size": 3001146,
           "VirtualSize": 3001146,
   ```

3. Open the URL `http://localhost:8090` in a browser and create a few sample
   orders. All of these are interacting with the Wasm server.

4. When you're all done, tear everything down by hitting `Ctrl+C` in the
   terminal you launched the application.

### Building and pushing a Wasm module

1. Create a Dockerfile that builds your Wasm application.

   Exactly how to do this varies depending on the programming language you use.

2. In a separate stage in your `Dockerfile`, extract the module and set it as
   the `ENTRYPOINT`.

   ```dockerfile
   # syntax=docker/dockerfile:1
   FROM scratch
   COPY --from=build /build/hello_world.wasm /hello_world.wasm
   ENTRYPOINT [ "/hello_world.wasm" ]
   ```

3. Build and push the image specifying the `wasi/wasm` architecture. Buildx
   makes this easy to do in a single command.

   ```console
   $ docker buildx build --platform wasi/wasm -t username/hello-world .
   ...
   => exporting to image                                                                             0.0s
   => => exporting layers                                                                            0.0s
   => => exporting manifest sha256:2ca02b5be86607511da8dc688234a5a00ab4d58294ab9f6beaba48ab3ba8de56  0.0s
   => => exporting config sha256:a45b465c3b6760a1a9fd2eda9112bc7e3169c9722bf9e77cf8c20b37295f954b    0.0s
   => => naming to docker.io/username/hello-world:latest                                            0.0s
   => => unpacking to docker.io/username/hello-world:latest                                         0.0s
   $ docker push username/hello-world
   ```

## Troubleshooting

This section contains instructions on how to resolve common issues.

### Unknown runtime specified

If you try to run a Wasm container without the [containerd image
store](./containerd.md), an error similar to the following displays:

```text
docker: Error response from daemon: Unknown runtime specified io.containerd.wasmedge.v1.
```

[Turn on the containerd feature](./containerd.md#enable-the-containerd-image-store)
in Docker Desktop settings and try again.

### Failed to start shim: failed to resolve runtime path

If you use an older version of Docker Desktop that doesn't support running Wasm
workloads, you will see an error message similar to the following:

```text
docker: Error response from daemon: failed to start shim: failed to resolve runtime path: runtime "io.containerd.wasmedge.v1" binary not installed "containerd-shim-wasmedge-v1": file does not exist: unknown.
```

Update your Docker Desktop to the latest version and try again.

## Known issues

- Docker Compose may not exit cleanly when interrupted. As a workaround, clean up `docker-compose` processes by sending them a SIGKILL (`killall -9 docker-compose`).
- Pushes to Docker Hub might give an error stating `server message: insufficient_scope: authorization failed`, even after signing in through Docker Desktop. As a workaround, run `docker login` in the CLI