client

wasimoff Client

We started work on a "client" implementation for Wasimoff in Go but the API is so simple that you can do all of that with curl or httpie and some JSON crafting.

An experimental client written in Bash can be found in ./client.sh. It worked great for our purposes but is considered experimental because the JSON is constructed using printf, which is not really safe.

Set the BROKER URL

The script expects the URL to the Broker in the environment variable BROKER. By default it assumes http://localhost:4080 for a locally deployed Broker on the same machine. If your Broker is somewhere else, it's best to set this URL once before running the other commands:

export BROKER=https://broker.example.com

Upload a WebAssembly Executable or auxilliary file

WebAssembly executables and data files can be uploaded to the Broker, which distributes it among Providers.

# upload an executable
./client.sh upload mytask.wasm
HTTP/1.1 200 OK
[...]

Upload OK, 188420 bytes

# upload data file (and store it with another name)
./client.sh upload data.bin [mydata.bin]
[...]

Execute a WebAssembly file

If at least one Provider is connected to the Broker and you've uploaded your executable, you can run it as if you were running the application locally. The script currently only forwards commandline arguments. If you need more customization, check the next section.

./client exec mytask.wasm --my task --arguments
POST /api/broker/v1/run HTTP/1.1
[... copy of offloading payload]

HTTP/1.1 200 OK
[...]

[{ "result": { "status": 0, "stderr": "", "stdout": "..." } }]

Run a prepared payload

For more customization prepare a JSON file with an array of tasks. You can take the payload from a ./client.sh exec call as a starter. The following is a configuration to transcode 10 seconds of a movie clip with ffmpeg.wasm. It uses loadfs to prepare the virtual filesystem with a file from storage and datafile to return a resulting file from the virtual filesystem. Note that you can configure an array of exec objects, which must all use the same executable.

{
  "bin": "ffmpeg.wasm",
  "exec": [{
    "envs": [ ],
    "args": [ "-i", "/movie.mp4", "-c:v", "h264", "-ss", "00:00", "-to", "00:10", "/clip.mp4" ],
    "loadfs": [ "movie.mp4" ],
    "datafile": "clip.mp4"
  }]
}

./client.sh upload ffmpeg.wasm
./client.sh upload movie.mp4
./client.sh run payload.json
HTTP/1.1 200 OK
[...]

[{
  "result": {
    "status": 0,
    "stderr": "[ ffmpeg logs ]",
    "stdout": "",
    "datafile": "[ base64-encoded file contents ]"
  }
}]

See examples/ for more examples and ../wasi-apps/ for the necessary WASI applications.