phantomjs host not found when run from php script

Question

I'm trying to run the rasterize.js script from php in order to generate pdfs of a page on my side. I've modified it slightly to give better error messages.

In PHP I've got the following code:

exec($cmd.' '.$script.' '.$url.' '.$filename.' 0.8 '.$domain.' '.$session_id);

The full command that runs looks like this:

/var/www/site/scripts/phantomjs /var/www/site/scripts/rasterize.js http://domain.site.com/index.php/pdf /var/www/pdfs/sample.pdf 0.8 domain.site.com ftrs44g1esnpjerqcube8bban1

If I run the exact same code from the command line, the PDF is created but if I run it from php I get the error (generated from rasterize.js) "Host domain.site.com not found".

Any ideas on what might be causing the issue?

rasterize.js

var page = require('webpage').create(),
    system = require('system'),
    address, output, size;

phantom.addCookie({
    'name':     'laravel_session',   /* required property */
    'value':    system.args[5],  /* required property */
    'domain':   system.args[4],           /* required property */
    'path' :'/'
});

page.onResourceError = function(resourceError) {
    page.reason = resourceError.errorString;
    page.reason_url = resourceError.url;
};

if (system.args.length < 3 || system.args.length > 6) {
    console.log('Usage: rasterize.js URL filename [paperwidth*paperheight|paperformat] [zoom]');
    console.log('  paper (pdf output) examples: "5in*7.5in", "10cm*20cm", "A4", "Letter"');
    phantom.exit(1);
} else {
    address = system.args[1];
    output = system.args[2];
    page.viewportSize = { width: 630, height: 891 };
    page.paperSize = { format: 'A4', orientation: 'portrait', margin: '1cm' };
    if (system.args.length > 3) {
        page.zoomFactor = system.args[3];
    }
    page.open(address, function (status) {
        if (status !== 'success') {
            console.log("Error opening url \"" + page.reason_url
                        + "\": " + page.reason);
            phantom.exit();
        } else {
            window.setTimeout(function () {
                page.render(output);
                phantom.exit();
            }, 200);
        }
    });
}

Answer 1

The issue was the VPS was behind a proxy. Using exec from PHP didn't copy the environment.

Just using putenv for the http_proxy and https_proxy variables solved it.