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Version: 1.x

Go HTTP Key-Value CRUD

This example is a WebAssembly component that demonstrates simple CRUD operations (Create, Read, Update, Destroy) with the wasi:keyvalue/store interface.

📦 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-keyvalue-crud:

shell
cd examples/component/http-keyvalue-crud

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.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 dependencies to run the application locally
  • Watch your code for changes and re-deploy when necessary.

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

shell
wash app list

Send a request​

The user provides keys as query strings and values as JSON payloads, with the application performing CRUD operations according to the HTTP method of the request.

To Create (or Update) a value:

shell
curl -X POST localhost:8000/crud/key -d '{"foo": "bar", "woo": "hoo"}'
text
{"message":"Set key", "value":"{"foo": "bar", "woo": "hoo"}"}

To Read a value:

shell
curl localhost:8000/crud/key
text
{"message":"Got key", "value":"{"foo": "bar", "woo": "hoo"}"}

To Destroy a value:

shell
curl -X DELETE localhost:8000/crud/key
text
{"message":"Deleted key"}

Read through the comments in main.go for step-by-step explanation of how the example works.

Clean up​

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

📖 Further reading​

When running this example with the wash dev command, wasmCloud uses its included NATS key-value store to back key-value operations, but the application could use another store like Redis with no change to the Go code.

You can learn more about capabilities like key-value storage are fulfilled by swappable providers in the wasmCloud Quickstart.