how to config apache2 and fastCGI to run my c++ application

Question

I have written a program with c++ and compiled it with gcc ( like the sample in the fastcgi.com) but i dont know how to run it on localhost.

everywhere i searched , i found the php configuration for mod_fcgi which wont work for c++.

does any body configured apache and mod_fcgi to run a c++ web application ???

Answer 1

mod_fcgi? I have found only mod_fastcgi and mod_fcgid. Apache configuration looks pretty simple for both. Lets compile FastCGI example and create a minimalistic Apache instance to serve it:

1. Install libfcgi-dev

2. Create temporary directory somewhere and compile the example from https://opensource.apple.com/source/FastCGI/FastCGI-4/fcgi/doc/fcgi-devel-kit.htm#S3.1

   When you simply run it, it already has some output:

   $ ./tiny-cgi 
   Content-type: text/html
   
   <title>FastCGI Hello!</title><h1>FastCGI Hello!</h1>Request number 1 running on host <i>(null)</i>
   

3. Install apache2 and libapache2-mod-fcgid; create configuration file apache.conf:

   User www-data
   Listen 8080
   PidFile apache.pid
   DocumentRoot .
   LoadModule fcgid_module /usr/lib/apache2/modules/mod_fcgid.so
   SetHandler fcgid-script
   Options +ExecCGI
   ErrorLog error.log
   

   User www-data is important, because it has access to /var/lib/apache2/fcgid/sock/, which is pretty important for fcgid (I am running on Debian, maybe somewhere else it will be different). Having DocumentRoot in the same directory with the rest is not very good, but this is just a quick example.

4. Run sudo /usr/sbin/apache2 -d . -f apache.conf -X

   That -X is for debug mode, when the server does not daemonize (does not detach), which is pretty handy for such playing.

5. Go to http://localhost:8080/tiny-cgi, where you will see output from your FastCGI program. If not, see error.log.

6. Stop Apache, install libapache2-mod-fastcgi, replace the two lines in configuration with:

   LoadModule fastcgi_module /usr/lib/apache2/modules/mod_fastcgi.so
   SetHandler fastcgi-script
   

7. Visit http://localhost:8080/tiny-cgi again.

Answer 2

Here's an example from my dev PC at home. It's a C++ web service running on 127.0.0.1:90 that I'm testing/debugging. The "FcgidIOTimeout" is set to 3600 so mod_fcgid won't timeout waiting for a response while I step through the fcgi process with gdb (the debugger). If it times out while debugging, the fcgi app will be killed. A little further down there is a ScriptAlias and a Directory telling Apache where the cgi folder is..."/home/dgnorton/prj/dfi/build/src/"...which is the build output folder for my project. You'll also need to check the permissions of that directory.

I only use this on my home system for debugging. Read the Apache and mod_fcgid docs before using any of this in the wild.

Listen 90

NameVirtualHost 127.0.0.1:90

<VirtualHost 127.0.0.1:90>
   ServerName www.example1.com
   DocumentRoot /var/www/dfi

   <IfModule fcgid_module> 
      FcgidIOTimeout 3600
   </IfModule>

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

    ScriptAlias /cgi/ /home/dgnorton/prj/dfi/build/src/
    <Directory "/home/dgnorton/src/dfi/build/src">
        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>