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HTTP Server

A simple HTTP server with multiple endpoints, implemented as a Wasm component and packaged for Cosmonic Control.

Deploy with Helm​

helm install http-server --version 0.1.2 oci://ghcr.io/cosmonic-labs/charts/http-trigger -f https://raw.githubusercontent.com/cosmonic-labs/control-demos/refs/heads/main/http-server/values.http-trigger.yaml

Repository: cosmonic-labs/control-demos/http-server
Languages: Go
Interfaces: wasi/http

Running on Kubernetes​

You will need a local Kubernetes environment with Cosmonic Control installed according to the Get Started guide.

Connect to the component at http://http-server.localhost.cosmonic.sh:

curl http://http-server.localhost.cosmonic.sh

Send a request​

You can send a request to the following endpoints:

GET /

Returns a list of available endpoints and their descriptions.

curl http://http-server.localhost.cosmonic.sh/
  /error - return a 500 error
  /form - echo the fields of a POST request
  /headers - echo your user agent back as a server side header
  /post - echo the body of a POST request

GET /error

Returns a 500 Internal Server Error.

curl -v http://http-server.localhost.cosmonic.sh/error
< HTTP/1.1 500 Internal Server Error
< content-type: text/plain; charset=utf-8
<
Something went wrong

GET /headers

Returns your User-Agent in the response headers.

curl -v http://http-server.localhost.cosmonic.sh/headers
< HTTP/1.1 200 OK
< x-your-user-agent: curl/8.7.1
<
Check headers!

POST /form

Echoes back form data from a POST request.

curl -X POST -d "field1=value1&field2=value2" http://http-server.localhost.cosmonic.sh/form
field2: value2
field1: value1

POST /post

Echoes back the entire body of a POST request.

curl -X POST -d "Hello World" http://http-server.localhost.cosmonic.sh/post
Hello World

Development​

Development requirements:

Clone the cosmonic-labs/control-demos repository:

git clone https://github.com/cosmonic-labs/control-demos.git
cd control-demos/http-server

Start the development loop:

wash dev

When using wash dev, the HTTP Server is accessible at localhost:8000. View the code and make changes in main.go.

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

Build the Wasm Binary​

Compile the component:

wash build

The .wasm binary will output to ./build.

Learn More​

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

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