https://github.com/wasm-outbound-http-examples/extism-c-pdk

Make HTTP requests from inside WASM in Extism PDK for C . Devcontainer.
https://github.com/wasm-outbound-http-examples/extism-c-pdk

c clang extism http-client http-request wasi wasm webassembly

Last synced: about 2 months ago
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Make HTTP requests from inside WASM in Extism PDK for C . Devcontainer.

• Host: GitHub
• URL: https://github.com/wasm-outbound-http-examples/extism-c-pdk
• Owner: wasm-outbound-http-examples
• License: mit
• Created: 2023-12-04T16:12:37.000Z (about 1 year ago)
• Default Branch: main
• Last Pushed: 2024-08-12T11:57:14.000Z (5 months ago)
• Last Synced: 2024-08-12T13:26:38.581Z (5 months ago)
• Topics: c, clang, extism, http-client, http-request, wasi, wasm, webassembly
• Language: C
• Homepage:
• Size: 5.86 KB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Use Extism PDK for С to send HTTP(s) requests from inside WASM

This devcontainer is configured to provide you a wasi-sdk 20.0.

[![Open in GitHub Codespaces](https://github.com/codespaces/badge.svg)](https://codespaces.new/wasm-outbound-http-examples/extism-c-pdk)

## Instructions for this devcontainer

Tested with Extism C PDK [v1.0.1](https://github.com/extism/c-pdk/tree/v1.0.1),

Extism CLI [v1.5.2](https://github.com/extism/cli/releases/tag/v1.5.2).

### Preparation

1. Open this repo in devcontainer, e.g. using Github Codespaces.

   Type or copy/paste following commands to devcontainer's terminal.

2. Download the `extism-pdk.h` header file, the only required part of Extism C PDK:

```sh

wget https://raw.githubusercontent.com/extism/c-pdk/v1.0.1/extism-pdk.h

```

### Building

1. Compile the example:

```sh

clang -o HTTPRequestingPlugin.wasm -mexec-model=reactor httpget.c

```

### Test with Extism CLI

For testing purposes, you can invoke functions from Extism plugins with [Extism CLI](https://github.com/extism/cli).

1. Install `Extism CLI` from Github releases: 

```sh

wget https://github.com/extism/cli/releases/download/v1.5.2/extism-v1.5.2-linux-amd64.tar.gz -O /tmp/extism.tar.gz

tar -xzf /tmp/extism.tar.gz -C /tmp ; mv /tmp/extism .

```

And now you have `extism` binary in current folder.

2. Run `httpget` function from extism plugin with CLI, allowing outbound connections to all hosts:

```sh

./extism call HTTPRequestingPlugin.wasm httpget --allow-host '*' --wasi

```

### Finish

Perform your own experiments if desired.

---

An [additional example](deprecated-extismpointer/README.md) using low-level API is in `deprecated-extismpointer` folder.

This devcontainer is based on ideas from [dev-wasm/dev-wasm-c](https://github.com/dev-wasm/dev-wasm-c).

Created for (wannabe-awesome) [list](https://github.com/vasilev/HTTP-request-from-inside-WASM)