How to deploy perl dancer app with cgi and calling external scripts?

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

I asked this question at StackOverflow. But I thought I may get a quicker response here.

I have had a webapp using CGI implementation. It basically uses system() calls to launch other programs and the results will be rendered in html. Now, I am trying to implement it using Dancer. In order to run these external programs, I created a "scripts" directory in /MyApp, so it's like /MyApp/scripts. I put all my other scripts there, which will be called in a route handler.

get '/analysis' => sub {
    if (session('user')  && session('logged_in')) {
    open FH, "<", "./scripts/test.out";
    my $msg = <FH>;
    close FH;
    chdir ("./scripts");
    system("call sth"); #call external programs to generate a "test.pn
+g"
    my $err;
    copy ("test.png", "../public/images/test.png") || ($err = "cannot 
+copy"); #copy the "test.png" to public/images directory, so the html 
+tt can use it
    my $img = "test.png";
       template 'analysis',{msg => $msg, img => $img, err => $err};
    }
    else {
    return redirect '/'
   }
};
[download]

However, I can launch this app successfully as a standalone or using plackup/starman. But I can not deploy it with CGI. I did every step using dancer's doc regarding cgi deployment. I can successfully using cgi to launch dancer's example app. but when I tried to launch my own as above, I always got the error:

app directory '/home/tester/MyApp/bin/..' isn't writable/executable and can't chmod it at /usr/local/share/perl/5.14.2/Dancer/Logger.pm line 16, referer:localhost

It seems a permission problem, but I don't know how to fix it. Is there a better way to launch an external program from route handler? where should I store these external programs, thus they can be executed by the dancer app when it was deployed as CGI. Could anyone help me? Thanks.

Xiaokuan

Comment on How to deploy perl dancer app with cgi and calling external scripts? Download Code

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Re: How to deploy perl dancer app with cgi and calling external scripts? by Corion (Patriarch) on Dec 30, 2013 at 08:14 UTC
According to the error message, your problem has nothing to do with the code you've shown. It seems that whatever Dancer::Logger you are trying to use wants to write to `/home/tester/MyApp/bin/..`. The user your CGI program is run as does not seem to have write permissions to that directory. You will have to consult with your system administrator on how to remedy that situation, or use a different Dancer::Logger.	[reply] [d/l]
Re: How to deploy perl dancer app with cgi and calling external scripts? by Anonymous Monk on Dec 30, 2013 at 08:22 UTC
... Dancer/Logger.pm ... Hold the presses `ack -i chmod ...site/lib/Dancer* 32: chmod($perm \| 0700, $logroot); 34: carp "app directory '$logroot' isn't writable/executabl +e and can't chmod it";` [download] Why does your Dancer setup think $logroot is in MyApp/bin/..? Usually its in some kind of log/ directory ... a writable log directory :) ... It seems a permission problem, but I don't know how to fix it. ... Learn to fix it :) man chmod ... :) CGI Help Guide , Troubleshooting Perl CGI scripts, File Permissions , File security, http://www.yolinux.com/TUTORIALS/LinuxTutorialManagingGroups.html Is there a better way to launch an external program from route handler? Sure , in the background with Proc::Background so it doesn't block the webpage:) Re: Providing feedback to Web GUI (Mojolicious) where should I store these external programs, thus they can be executed by the dancer app when it was deployed as CGI. if they're perlish, bin sounds good Could anyone help me? Thanks. Maybe, but you've got to do most of the typing and checking :) I asked this question at StackOverflow. Crossposted to http://stackoverflow.com/questions/20833945/how-to-deploy-perl-dancer-app-with-cgi-and-calling-external-scripts I cross-linked this cross-postings for maximum collaboration efficiency But I thought I may get a quicker response here. There are checklist for that :) Basic debugging checklist , brian's Guide to Solving Any Perl Problem, CGI Help Guide , Troubleshooting Perl CGI scripts	[reply] [d/l]