Getting CGI to work in Apache2

[h4x0rmx]

I'm running 10.04 with Apache2/PHP5.x
I wanted to test some basic cgi scripts, but my browser is displaying the code (#!...)
If I run the scripts on the console, they work fine so CGI is not the problem, it's apache.
To install the CGI module I ran
sudo apt-get install libapache2-mod-perl2
with no problems.
By the way, I installed Apache through apt-get instead of doing it manually, but it seems that the installation divides the conf file in different parts, so the regular apache2.conf has this:


# Include module configuration:
Include /etc/apache2/mods-enabled/*.load
Include /etc/apache2/mods-enabled/*.conf

# Include all the user configurations:
Include /etc/apache2/httpd.conf

# Include ports listing
Include /etc/apache2/ports.conf
# Include generic snippets of statements
Include /etc/apache2/conf.d/

# Include the virtual host configurations:
Include /etc/apache2/sites-enabled/under /etc/apache2/mods-enabled/ there's a file (or shortcut to a file) called cgi.load which contains this one line:

LoadModule cgi_module /usr/lib/apache2/modules/mod_cgi.somod_cgi.so does exist.

I can't figure out what I need to do to get CGI working on my server.
Any help?
I will really appreciate it!

[cdenley]

It should work out-of-the-box.


echo -e '#!/usr/bin/perl\nprint "Content-type: text/plain\\n\\n";\nprint "It works!\\n";'|sudo tee /usr/lib/cgi-bin/test.pl
sudo chmod 755 /usr/lib/cgi-bin/test.pl
echo -e "GET /cgi-bin/test.pl HTTP/1.0\n"|nc -q 1 127.0.0.1 80

[gzarkadas]

Check that your httpd.conf has the line:


AddHandler cgi-script .cgi
(or .pl if you use perl scripts)

Also your site configuration file (inside sites-available) has the lines:


ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
<Directory "/usr/lib/cgi-bin">
AllowOverride None
Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
...
</Directory>
The important settings are with bold; the other are depending on your config, so they maybe (or need to be) different. Also the directory entry should have Allow and Deny options.

I don't use Perl as cgi, so things may need to be different for your case; try and see if they work for you.

[cdenley]

Check that your httpd.conf has the line:


AddHandler cgi-script .cgi
(or .pl if you use perl scripts)

Also your site configuration file (inside sites-available) has the lines:


ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
<Directory "/usr/lib/cgi-bin">
AllowOverride None
Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
...
</Directory>
The important settings are with bold; the other are depending on your config, so they maybe (or need to be) different. Also the directory entry should have Allow and Deny options.

I don't use Perl as cgi, so things may need to be different for your case; try and see if they work for you.

The file httpd.conf is not used in ubuntu.

[h4x0rmx]

@cdenley
this is what I get


$ echo -e '#!/usr/bin/perl\nprint "Content-type: text/html\\n\\n";\nprint "Hello, world!\\n";'|sudo tee /usr/lib/cgi-bin/test.pl
[sudo] password for h4x0r:
#!/usr/bin/perl
print "Content-type: text/html\n\n";
print "Hello, world!\n";

@gzarkadas
like cdenley said, that file is empty

[gzarkadas]

The file httpd.conf is not used in ubuntu.

It is empty, because this is where user settings are meant to be placed (from the Apache docs), but nobody forbids you to use it. And it works; that's how I have set up viewvc to browse my local cvs.

[h4x0rmx]

It is empty, because this is where user settings are meant to be placed (from the Apache docs), but nobody forbids you to use it. And it works; that's how I have set up viewvc to browse my local cvs.

So, is it here where I should add the handler?
Should it be in some other conf file?
Do my cgi scripts need certain permissions to run?

[bredman]

If Apache displays the contents of a file, it is probably because Apache thinks that the file is not executable.

Use the command
ls -l <filename>
and check if an x shows for the file.

Post the results of the command if you don't know what you are doing.

[cdenley]

@cdenley
this is what I get


$ echo -e '#!/usr/bin/perl\nprint "Content-type: text/html\\n\\n";\nprint "Hello, world!\\n";'|sudo tee /usr/lib/cgi-bin/test.pl
[sudo] password for h4x0r:
#!/usr/bin/perl
print "Content-type: text/html\n\n";
print "Hello, world!\n";


Well, you ran the first command. I was more interested in the output from the third after changing permissions with the second.

[cdenley]

So, is it here where I should add the handler?
Should it be in some other conf file?
Do my cgi scripts need certain permissions to run?

You don't need any handler for cgi with a scriptalias. If you wanted to be able to place CGI scripts anywhere, though, uncomment the handler in /etc/apache2/mods-available/mime.conf.


#
# AddHandler allows you to map certain file extensions to "handlers":
# actions unrelated to filetype. These can be either built into the server
# or added with the Action directive (see below)
#
# To use CGI scripts outside of ScriptAliased directories:
# (You will also need to add "ExecCGI" to the "Options" directive.)
#
#AddHandler cgi-script .cgi

[h4x0rmx]

@bredman
I get
$ls -l hello.cgi
-rwxr-xr-x 1 h4x0r h4x0r 148 2006-09-08 12:35 hello.cgi

@cdenley
I'm storing my cgis inside /var/www/cgi
where /var/www/ is the root dir for Apache

Do I need to move them somewhere else? or should I comment the line you mentioned in mime.conf?

[Sorry! I'm a little confused]

[cdenley]

@bredman
I get
$ls -l hello.cgi
-rwxr-xr-x 1 h4x0r h4x0r 148 2006-09-08 12:35 hello.cgi

@cdenley
I'm storing my cgis inside /var/www/cgi
where /var/www/ is the root dir for Apache

Do I need to move them somewhere else? or should I comment the line you mentioned in mime.conf?

[Sorry! I'm a little confused]

It depends on your vhost configuration. On the default vhost, by default, /usr/lib/cgi-bin is defined as a scriptalias, so you can place cgi scripts there. If you want to place cgi scripts in directories which aren't defined as a scriptalias, then you need to uncomment the line I mentioned.

[h4x0rmx]

It depends on your vhost configuration. On the default vhost, by default, /usr/lib/cgi-bin is defined as a scriptalias, so you can place cgi scripts there. If you want to place cgi scripts in directories which aren't defined as a scriptalias, then you need to uncomment the line I mentioned.

@cdenley (http://ubuntuforums.org/member.php?u=204457)
I did uncomment that line and I get a 403 Forbidden error, which I'd think is better than displaying the content of the file.
I tried to change the permissions of the directory and file, but it didn't work.
I tried:

$ chmod a+rx ./cgi/
$ chmod a+rx ./cgi/*
$ chmod a+rx ./cgi/hello.cgi
$ sudo chown -R h4x0r /var/www/cgi/hello.cgi

Would you guys know how to solve this?
I appreciate your help!

[h4x0rmx]

I took a look at the Apache logs and I found this:


[Wed May 12 00:00:00 2010] [error] [client 127.0.0.1] Options ExecCGI is off in this directory: /var/www/cgi/hello.cgi

So I guess I have to add a <Directory> entry, but where? I've never done it, so I'm not sure what info goes into that... is this what I have to do?

[cdenley]

I took a look at the Apache logs and I found this:


[Wed May 12 00:00:00 2010] [error] [client 127.0.0.1] Options ExecCGI is off in this directory: /var/www/cgi/hello.cgi

So I guess I have to add a <Directory> entry, but where? I've never done it, so I'm not sure what info goes into that... is this what I have to do?

Yes, or modify the options on an existing one. Either that, or use /usr/lib/cgi-bin which already has ExecCGI enabled. Post your existing vhost configuration, and we can tell you what to change. By default, this would be /etc/apache2/sites-available/default.

[h4x0rmx]

I renamed the /cgi/ folder to /cgi-bin/ and had no luck.
This is my /etc/apache2/sites-enabled/000-default file:


<VirtualHost *:80>
ServerAdmin webmaster@localhost

DocumentRoot /var/www
<Directory />
Options FollowSymLinks
AllowOverride None
</Directory>
<Directory /var/www/>
Options Indexes FollowSymLinks MultiViews
AllowOverride None
Order allow,deny
allow from all
</Directory>

ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
<Directory "/usr/lib/cgi-bin">
AllowOverride None
Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
Order allow,deny
Allow from all
</Directory>

# I added this just to see if it worked
ScriptAlias /cgi/ /usr/lib/cgi-bin/
<Directory "/usr/lib/cgi-bin">
AllowOverride None
Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
Order allow,deny
Allow from all
</Directory>


ErrorLog /var/log/apache2/error.log

# Possible values include: debug, info, notice, warn, error, crit,
# alert, emerg.
LogLevel warn

CustomLog /var/log/apache2/access.log combined

Alias /doc/ "/usr/share/doc/"
<Directory "/usr/share/doc/">
Options Indexes MultiViews FollowSymLinks
AllowOverride None
Order deny,allow
Deny from all
Allow from 127.0.0.0/255.0.0.0 ::1/128
</Directory>

</VirtualHost>

[WorMzy]

You might need to restart apache for any changes to take effect:
sudo /etc/init.d/apache2 restart

[h4x0rmx]

You might need to restart apache for any changes to take effect:
sudo /etc/init.d/apache2 restart

I did restart it! :)

I now get a Not Found error when tyring to go to http://localhost/cgi/hello.cgi
and a 403 Forbidden when trying to go to http://localhost/cgi/

Error log:


[Wed May 12 00:00:00 2010] [error] [client 127.0.0.1] script not found or unable to stat: /usr/lib/cgi-bin/hello.cgi
[Wed May 12 00:00:00 2010] [error] [client 127.0.0.1] attempt to invoke directory as script: /usr/lib/cgi-bin/

[WorMzy]

Well, that's a good sign. I can't access my /cgi-bin folder either, so it looks like it's at least treating your /cgi directory in the same manner as a cgi-bin directory. I think the problem now is the script itself.

Try copying this to an empty file in your /cgi directory:

#! /usr/bin/perl
use CGI;
my $q=new CGI;
print $q->header();
print $q->start_html(-title=>'Test',-BGCOLOR=>'#AAAAAA');
Name it test.cgi or something, then try opening it in your webbrowser. It should make a blank page with the title "Test" and a grey background colour.

If that works, there's a problem with your script.

[h4x0rmx]

Well, that's a good sign. I can't access my /cgi-bin folder either, so it looks like it's at least treating your /cgi directory in the same manner as a cgi-bin directory. I think the problem now is the script itself.

Try copying this to an empty file in your /cgi directory:

#! /usr/bin/perl
use CGI;
my $q=new CGI;
print $q->header();
print $q->start_html(-title=>'Test',-BGCOLOR=>'#AAAAAA');Name it test.cgi or something, then try opening it in your webbrowser. It should make a blank page with the title "Test" and a grey background colour.

If that works, there's a problem with your script.

I created the file. I tried running it in the console, but I had to change the permissions with

$ chmod a+rx ./cgi/test.cgi
I can't open the script in the browser, though.
The logs keep saying:

[Wed May 12 00:00:00 2010] [error] [client 127.0.0.1] script not found or unable to stat: /usr/lib/cgi-bin/test.cgi

[h4x0rmx]

mm... Is it looking for /usr/lib/cgi-bin/test.cgi instead of /var/www/cgi/test.cgi???

[WorMzy]

I think that's it. If you change this line in your 000-default file

ScriptAlias /cgi/ /usr/lib/cgi-bin/
To

ScriptAlias /cgi/ /var/www/cgi/

Or, if you store the scripts at /usr/lib/cgi-bin it'll work as it is.

[h4x0rmx]

I think that's it. If you change this line in your 000-default file

ScriptAlias /cgi/ /usr/lib/cgi-bin/To

ScriptAlias /cgi/ /var/www/cgi/Or, if you store the scripts at /usr/lib/cgi-bin it'll work as it is.

That did it! It works now!


ScriptAlias /cgi/ /var/www/cgi/
<Directory "/usr/lib/cgi-bin">
AllowOverride None
Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
Order allow,deny
Allow from all
</Directory>

Thank you all for all the help! I appreciate it!