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Version: 1.x

Go HTTP Password Checker

This example is a WebAssembly component that checks password strength over HTTP.

The application...

📦 Dependencies​

Before starting, ensure that you have the following installed in addition to the Go (1.23+) toolchain:

👟 Run the example​

Clone the wasmCloud/go repository:

shell
git clone https://github.com/wasmCloud/go.git

Change directory to examples/component/http-password-checker:

shell
cd examples/component/http-password-checker

In addition to the standard elements of a Go project, the example directory includes the following files and directories:

  • build/: Target directory for compiled .wasm binaries
  • gen/: Target directory for Go bindings of interfaces
  • wit/: Directory for WebAssembly Interface Type (WIT) packages that define interfaces
  • bindings.wadge_test.go: Automatically generated test bindings
  • wadm.yaml: Declarative application manifest
  • wasmcloud.lock: Automatically generated lockfile for WIT packages
  • wasmcloud.toml: Configuration file for a wasmCloud application

Start a local development loop​

Run wash dev to start a local development loop:

shell
wash dev

The wash dev command will:

  • Start a local wasmCloud environment
  • Build this component
  • Deploy your application and all requirements to run the application locally, including...
    • Your locally built component
    • The HTTP server provider, which will receive requests from the outside world (on port 8000 by default)
    • Necessary links between providers and your component so your component can handle web traffic
  • Watch your code for changes and re-deploy when necessary.

Once the application is deployed, open another terminal tab. To ensure that the application has reached Deployed status, you can use wash app list:

shell
wash app list

Send a request​

You can send a request with a JSON payload to the /api/v1/check endpoint:

shell
curl localhost:8000/api/v1/check -d '{"value": "tes12345!"}'
json
{
    "valid": false, "message": "insecure password, try including more special characters, using uppercase letters or using a longer password"
}

Clean up​

You can cancel the wash dev process with Ctrl-C.

⚠️ Issues/FAQ​

curl produces a "failed to invoke" error​

If curling produces...

text
failed to invoke `wrpc:http/incoming-handler.handle`: failed to invoke `wrpc:http/incoming-handler@0.1.0.handle`: failed to shutdown synchronous parameter channel: not connected%

...the HTTP server may not have finished starting up. You can check that the application has reached Deployed status with wash app list.

If the issue persists, you may have a lingering HTTP server provider running on your system. You can use pgrep to check:

shell
pgrep -la ghcr_io
text
4007604 /tmp/wasmcloudcache/NBCBQOZPJXTJEZDV2VNY32KGEMTLFVP2XJRZJ5FWEJJOXESJXXR2RO46/ghcr_io_wasmcloud_http_server_0_23_1

📖 Further reading​

To learn how to extend this example with additional capabilities, see the Adding Capabilities section of the wasmCloud documentation.

For more on building components, see the Component Developer Guide in the wasmCloud documentation.