Super Web Framework Wren Baron

スーパーウェブフレームワーク Wren Baron

This is a small proof of concept to execute Wren Scripts inside a web environment.

This is made using PHP as a bridge in a cgi-bin executable.

First create a new directory and put index.php in with the the code.

We are using Wren Console for additional modules such as JSON support.

index.php

The PHP script simply encodes a JSON object with environment variables such as GET and POST params and then pass them to the wren script as an argument.

Also the final 2>&1 enables debugging the Wren scripts so they output errors as well.

<?php

session_start();

$env = escapeshellarg(json_encode([
    "get" => $_GET,
    "post" => $_POST,
    "server" => $_SERVER,
    "session" => session_id(),
    "pwd" => getcwd()
    ]));

$wren = "../wrenc index.wren $env 2>&1";

passthru($wren);
?>

index.wren

This file will get the enviroment as a JSON string and parse it to obtain the GET params.

import "runtime" for Runtime
import "os" for Process
import "json" for JSON

var args = Process.allArguments
var env = JSON.parse(args[2])
var name = env["get"]["name"]

System.print("<h1>Hello From Wren %(Runtime.WREN_VERSION)</h1>")
System.print("<h2>This is rendered from <strong>Wren</strong></h2>")
System.print("<p>Hello <strong>%(name)</strong></p>")

The URL can now use the name param in a GET request.

cgi-bin/hello/?name=Camilo

Wren Console Compilation

The version provided here was dynamically linked with libc 2.17 since that was the available in the shared hosting.

If we want to check the libc version, you can use

$ ldd --version
ldd (GNU libc) 2.17
Copyright (C) 2012 Free Software Foundation, Inc.

If we try to use wrenc in an enviroment that does not have the correct libc we will see an error similar to this:

./wrenc: /lib64/libm.so.6: version `GLIBC_2.29' not found (required by ./wrenc)

The provided make command builds the wrenc binary for this linux environment

$ make install

We use an old Ubuntu for the Dockerfile that already has libc 2.17.

FROM ubuntu:13.04

RUN sed -i 's/archive.ubuntu/old-releases.ubuntu/g' /etc/apt/sources.list
RUN apt-get update
RUN apt-get install build-essential -y

COPY . /wrenc

WORKDIR /wrenc/projects/make/
RUN make config=release_64bit

RUN /wrenc/bin/wrenc -v

# So we can execute commands
# and do not exits
CMD tail -f /dev/null

Credits

Made with ♥ by Ninjas.cl .