I have this very simple Mojolicious Lite script:
#!/usr/bin/env perl
use v5.10;
use WWW::Mechanize::PhantomJS;
use Mojolicious::Lite;
my $mech = WWW::Mechanize::PhantomJS->new();
$mech->get('http://stackoverflow.com/');
get '/test' => sub {
my $c = shift;
$mech->get("https://stackoverflow.com/questions");
$c->render(template => 'activity');
};
app->secrets(['test secret']);
app->start;
__DATA__
@@ activity.html.ep
<!DOCTYPE html>
<html>
<head><title>Test</title></head>
<body><h2>Test</h2></body>
</html>
When I start it using hypnotoad in foreground mode (hypnotoad -f ./script.pl), and access /test url -- I get my test page, and clean logs:
[Fri Dec 11 18:00:23 2015] [info] Listening at "http://*:8080"
[Fri Dec 11 18:00:23 2015] [info] Manager 3011 started
[Fri Dec 11 18:00:23 2015] [info] Creating process id file "/home/username/pc_activity/demo_site/hypnotoad.pid"
When I start it using background mode (hypnotoad ./script.pl), and access /test url -- I get "something went very wrong" error page with throwing up raptor.
[Fri Dec 11 17:58:07 2015] [info] Listening at "http://*:8080"
[Fri Dec 11 17:58:07 2015] [info] Manager 2964 started
[Fri Dec 11 17:58:07 2015] [info] Creating process id file "/home/username/pc_activity/demo_site/hypnotoad.pid"
[Fri Dec 11 17:58:14 2015] [error] Error while executing command: get: Server returned error message Can't connect to localhost:8910
Connection refused at /usr/local/share/perl/5.18.2/LWP/Protocol/http.pm line 47, <DATA> line 49.
instead of data at /usr/local/share/perl/5.18.2/Selenium/Remote/Driver.pm line 310.
It turns out the localhost:8910 is default settings for PhanomJS to run at in webdriver mode. Which it isn't on my machine. But even if I start it, and then access the URL, I still get an error:
[Fri Dec 11 18:41:01 2015] [error] Error while executing command: get: Server returned error message Variable Resource Not Found - {"headers":{"Accept":"application/json","Connection":"TE, close","Content-Length":"45","Content-Type":"application/json; charset=utf-8","Host":"localhost:8910","TE":"deflate,gzip;q=0.3","User-Agent":"libwww-perl/6.15"},"httpVersion":"1.1","method":"POST","post":"{\"url\":\"https://stackoverflow.com/questions\"}","url":"/session/98799e80-a060-11e5-8907-0b365878087d/url","urlParsed":{"anchor":"","query":"","file":"url","directory":"/session/98799e80-a060-11e5-8907-0b365878087d/","path":"/session/98799e80-a060-11e5-8907-0b365878087d/url","relative":"/session/98799e80-a060-11e5-8907-0b365878087d/url","port":"","host":"","password":"","user":"","userInfo":"","authority":"","protocol":"","source":"/session/98799e80-a060-11e5-8907-0b365878087d/url","queryKey":{},"chunks":["session","98799e80-a060-11e5-8907-0b365878087d","url"]}} instead of data at /usr/local/share/perl/5.18.2/Selenium/Remote/Driver.pm line 310.
I guess, I don't understand, why does it run in foreground mode, and not in background mode. And then, what can I do to make it run in background mode?
The reason it will not run in background mode is because of threading. After you start hypnotoad in background it spawns some processes.
664161507 46028 1 0 10:34AM ?? 0:00.01 script.pl
664161507 46029 46028 0 10:34AM ?? 0:00.08 script.pl
664161507 46030 46028 0 10:34AM ?? 0:00.01 script.pl
664161507 46031 46028 0 10:34AM ?? 0:00.01 script.pl
664161507 46032 46028 0 10:34AM ?? 0:00.01 script.pl
These will not have access to the PhantomJS you created in the parent process. I didn't look into how this communication is done, but if you want to share PhantomJS for your workers you need to make it a separate service.
If you however want to have a PhantomJS for each request you can initialize it in the request, but I don't necessarily encourage this approach:
get '/test' => sub {
my $c = shift;
my $mech = WWW::Mechanize::PhantomJS->new();
$mech->get('http://stackoverflow.com/');
$mech->get("https://stackoverflow.com/questions");
$c->render(template => 'activity');
};