CGI with Reverse Proxy Settings (Apache)

Question

I have two VMs running two webapps. We want to use example.com/foo for accessing VM1, and example.com/bar for accessing VM2.

For both VMs I need to call a cgi script for downloading. So I have ScriptAlias "/cgi-bin/" "/opt/example/lib/", and use www.example.com/cgi-bin/download.pl to download files.

When the VMs have its own domain, it works fine. But now we want to have the example.com/foo and example.com/bar setup, the download function on VM2 stopped working. As both VMs will call the script on VM1, and VM1 will return an error.

How shall I setup the Apache, so I can use example.com/foo/cgi-bin/download.pl to download the files on VM1 and use example.com/bar/cgi-bin/download.pl to download the files on VM2?

I have tried to set ScriptAlias "/foo/cgi-bin/" "/opt/example/lib/" but it didn't work.

Apache conf on VM1,

<VirtualHost *:80>
    ServerName example.com
    ScriptAlias "/cgi-bin/" "/opt/example/lib/"
    ProxyRequests Off
    <Proxy *>
        Order deny,allow
        Allow from all
    </Proxy>
    ProxyPreserveHost On
    ProxyPass /bar http://x.x.x.x/bar
    ProxyPassReverse /bar http://x.x.x.x/bar
</VirtualHost>

Alias /foo /opt/example/script/fastcgi.pl/

<Directory "/opt/example/lib/">
    Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
    Require all granted
    AddHandler cgi-script .pl
    SetHandler cgi-script
</Directory>

FastCgiServer /opt/example/script/fastcgi.pl -processes 3 -idle-timeout 3600

<Directory "/opt/example/script/">
    Require all granted
</Directory>

Apache conf on VM2,

<VirtualHost *:80>
    ServerName example2.com
    ScriptAlias "/cgi-bin/" "/opt/example/lib/"
</VirtualHost>

Alias /bar /opt/example/script/fastcgi.pl/

<Directory "/opt/example/lib/">
    Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
    Require all granted
    AddHandler cgi-script .pl
    SetHandler cgi-script
</Directory>

FastCgiServer /opt/example/script/fastcgi.pl -processes 3 -idle-timeout 3600

<Directory "/opt/example/script/">
    Require all granted
</Directory>

Answer 1

In your scenario you actually need three webservers:

• webapp "foo"
• webapp "bar"
• a front end webserver

The front end webserver virtual host will look like:

<VirtualHost *:80>
    ServerName example.com
    ProxyRequests Off
    <Proxy *>
        Order deny,allow
        Allow from all
    </Proxy>
    ProxyPreserveHost On
    ProxyPass /bar http://x.x.x.x/
    ProxyPassReverse /bar http://x.x.x.x/
    ProxyPass /foo http://x.x.x.x/
    ProxyPassReverse /foo http://x.x.x.x/
</VirtualHost>

Then set up your VM virtual hosts as you had done when they worked.

The "front end" webserver could be a separate virtual host running on one of the two existing VMs if you don't want to create another VM specifically for it.