How to reverse proxy specific ports to a different server behind a firewall using Apache mod_proxy

Question

I have two Web severs, one Apache 2 and the other IIS 8, and both are on a LAN behind a firewall. I have ports 80, 443, and 8080-8088 open on the firewall. I have an externally hosted DNS A record pointing to my firewall, and firewall rules that redirect those ports to the Apache server. I also have a DNS entry on the LAN that points the A record to a local address from within the firewall. (i.e., outside the firewall, www.example.com points to 1.2.3.4, but inside the same address points to 192.168.1.1). I want ports 8080-8084 on the Apache server to be redirected to the IIS server, and the remaining ports (80, 443, 8085-8088) to be handled by Apache as normal. All the traffic is either HTTP (or possibly HTTPS in the future if needed), so even though the port numbers are non-standard, all the traffic is normal Website stuff.

For the example, let's assume the following:

Public hostname: www.example.com
Public IP address: 1.2.3.4
LAN hostname for Apache server (where www.example.com points): apache.example.local
IP address for Apache server on the LAN: 192.168.1.1
LAN hostname for IIS server (not accessible from outside the LAN): iis.example.local
IP address for IIS server on the LAN: 192.168.1.2

I tried to setup a proxy rule for each of these scenarios:

h ttp://www.example.com/ points to Apache's default website (apache:80/).
h ttps://www.example.com/ points to Apache's SSL website (apache:443/)
h ttp://www.example.com:8080/ points to IIS' default website (iis:80/)
h ttps://www.example.com:8080/ points to IIS' SSL website (iis:443/) - I couldn't figure out how to do that, so I pointed it to h ttps://www.example.com:8083/, though I'd rather have it work as intended
h ttp://www.example.com:8081/wiki/ points to IIS' wiki (iis:8081/w/) - redirects the port and does a URL modification
h ttp://www.example.com:8088/ points to a virtual host on Apache (apache:8088/)

(Note: "http" is shown as "h ttp" above to avoid having the site think I am spamming this post with links.)

Here is what I came up with thanks to the help of another question and looking at the VirtualHost docs from Apache. Unfortunately, it doesn't work.

Port 80 and 8088 work correctly. Port 443 cannot complete the secure connection (which may be completely unrelated, so I won't worry about that now). Port 8080 just hangs, and the browser eventually gives up. Ports 8081-8087 do the same thing. That leads me to believe that the proxying is not working correctly.

In addition to any help in getting this working, feel free to suggest ways to make it simpler/shorter/more efficient/more secure. Thanks!

I replaced the conceptual code in my original post with my complete (semi-working) httpd.conf file (and updated the notes above to reflect the change): # # This is the main Apache HTTP server configuration file. It contains the # configuration directives that give the server its instructions. # See http://httpd.apache.org/docs/2.4/> for detailed information. # In particular, see # http://httpd.apache.org/docs/2.4/mod/directives.html> # for a discussion of each configuration directive. # # Do NOT simply read the instructions in here without understanding # what they do. They're here only as hints or reminders. If you are unsure # consult the online docs. You have been warned.
# # Configuration and logfile names: If the filenames you specify for many # of the server's control files begin with "/" (or "drive:/" for Win32), the # server will use that explicit path. If the filenames do not begin # with "/", the value of ServerRoot is prepended -- so 'log/access_log' # with ServerRoot set to '/www' will be interpreted by the # server as '/www/log/access_log', where as '/log/access_log' will be # interpreted as '/log/access_log'.

#
# ServerRoot: The top of the directory tree under which the server's
# configuration, error, and log files are kept.
#
# Do not add a slash at the end of the directory path.  If you point
# ServerRoot at a non-local disk, be sure to specify a local disk on the
# Mutex directive, if file-based mutexes are used.  If you wish to share the
# same ServerRoot for multiple httpd daemons, you will need to change at
# least PidFile.
#
ServerRoot "/etc/httpd"

#
# Listen: Allows you to bind Apache to specific IP addresses and/or
# ports, instead of the default. See also the <VirtualHost>
# directive.
#
# Change this to Listen on specific IP addresses as shown below to 
# prevent Apache from glomming onto all bound IP addresses.
#
#Listen 12.34.56.78:80
#Listen 80

#
# Dynamic Shared Object (DSO) Support
#
# To be able to use the functionality of a module which was built as a DSO you
# have to place corresponding `LoadModule' lines at this location so the
# directives contained in it are actually available _before_ they are used.
# Statically compiled modules (those listed by `httpd -l') do not need
# to be loaded here.
#
# Example:
# LoadModule foo_module modules/mod_foo.so
#
Include conf.modules.d/*.conf

#
# If you wish httpd to run as a different user or group, you must run
# httpd as root initially and it will switch.  
#
# User/Group: The name (or #number) of the user/group to run httpd as.
# It is usually good practice to create a dedicated user and group for
# running httpd, as with most system services.
#
User apache
Group apache

# 'Main' server configuration
#
# The directives in this section set up the values used by the 'main'
# server, which responds to any requests that aren't handled by a
# <VirtualHost> definition.  These values also provide defaults for
# any <VirtualHost> containers you may define later in the file.
#
# All of these directives may appear inside <VirtualHost> containers,
# in which case these default settings will be overridden for the
# virtual host being defined.
#

#
# ServerAdmin: Your address, where problems with the server should be
# e-mailed.  This address appears on some server-generated pages, such
# as error documents.  e.g. admin@your-domain.com
#
ServerAdmin no-reply@example.com

#
# ServerName gives the name and port that the server uses to identify itself.
# This can often be determined automatically, but we recommend you specify
# it explicitly to prevent problems during startup.
#
# If your host doesn't have a registered DNS name, enter its IP address here.
#
#ServerName www.example.com:80
ServerName www.example.com:80

#
# Deny access to the entirety of your server's filesystem. You must
# explicitly permit access to web content directories in other 
# <Directory> blocks below.
#
<Directory />
    AllowOverride none
    Require all denied
</Directory>

#
# Note that from this point forward you must specifically allow
# particular features to be enabled - so if something's not working as
# you might expect, make sure that you have specifically enabled it
# below.
#

#
# DocumentRoot: The directory out of which you will serve your
# documents. By default, all requests are taken from this directory, but
# symbolic links and aliases may be used to point to other locations.
#
#DocumentRoot "/var/www/html"
DocumentRoot "/var/www/www.example.com_80"

#
# Relax access to content within /var/www.
#
<Directory "/var/www">
    AllowOverride None
    # Allow open access:
    Require all granted
</Directory>

# Further relax access to the default document root:
#<Directory "/var/www/html">
<Directory "/var/www/www.example.com_80">
    #
    # Possible values for the Options directive are "None", "All",
    # or any combination of:
    #   Indexes Includes FollowSymLinks SymLinksifOwnerMatch ExecCGI MultiViews
    #
    # Note that "MultiViews" must be named *explicitly* --- "Options All"
    # doesn't give it to you.
    #
    # The Options directive is both complicated and important.  Please see
    # http://httpd.apache.org/docs/2.4/mod/core.html#options
    # for more information.
    #
    Options Indexes FollowSymLinks

    #
    # AllowOverride controls what directives may be placed in .htaccess files.
    # It can be "All", "None", or any combination of the keywords:
    #   Options FileInfo AuthConfig Limit
    #
    #AllowOverride None
    AllowOverride Options

    #
    # Controls who can get stuff from this server.
    #
    Require all granted
</Directory>

#
# DirectoryIndex: sets the file that Apache will serve if a directory
# is requested.
#
<IfModule dir_module>
    #DirectoryIndex index.html
    DirectoryIndex index.php index.html index.htm Default.htm
</IfModule>

#
# The following lines prevent .htaccess and .htpasswd files from being 
# viewed by Web clients. 
#
<Files ".ht*">
    Require all denied
</Files>
# WM: Added the Windows _vti_cnf
<Files "_vti_cnf">
    Require all denied
</Files>
# WM: Added the Dreamweaver _notes
<Files "_notes*">
    Require all denied
</Files>

#
# ErrorLog: The location of the error log file.
# If you do not specify an ErrorLog directive within a <VirtualHost>
# container, error messages relating to that virtual host will be
# logged here.  If you *do* define an error logfile for a <VirtualHost>
# container, that host's errors will be logged there and not here.
#
ErrorLog "logs/error_log"

#
# LogLevel: Control the number of messages logged to the error_log.
# Possible values include: debug, info, notice, warn, error, crit,
# alert, emerg.
#
#LogLevel warn
LogLevel notice

<IfModule log_config_module>
    #
    # The following directives define some format nicknames for use with
    # a CustomLog directive (see below).
    #
    LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
    LogFormat "%h %l %u %t \"%r\" %>s %b" common

    <IfModule logio_module>
      # You need to enable mod_logio.c to use %I and %O
      LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %I %O" combinedio
    </IfModule>

    #
    # The location and format of the access logfile (Common Logfile Format).
    # If you do not define any access logfiles within a <VirtualHost>
    # container, they will be logged here.  Contrariwise, if you *do*
    # define per-<VirtualHost> access logfiles, transactions will be
    # logged therein and *not* in this file.
    #
    #CustomLog "logs/access_log" common

    #
    # If you prefer a logfile with access, agent, and referer information
    # (Combined Logfile Format) you can use the following directive.
    #
    CustomLog "logs/access_log" combined
</IfModule>

<IfModule alias_module>
    #
    # Redirect: Allows you to tell clients about documents that used to 
    # exist in your server's namespace, but do not anymore. The client 
    # will make a new request for the document at its new location.
    # Example:
    # Redirect permanent /foo http://www.example.com/bar

    #
    # Alias: Maps web paths into filesystem paths and is used to
    # access content that does not live under the DocumentRoot.
    # Example:
    # Alias /webpath /full/filesystem/path
    #
    # If you include a trailing / on /webpath then the server will
    # require it to be present in the URL.  You will also likely
    # need to provide a <Directory> section to allow access to
    # the filesystem path.

    #
    # ScriptAlias: This controls which directories contain server scripts. 
    # ScriptAliases are essentially the same as Aliases, except that
    # documents in the target directory are treated as applications and
    # run by the server when requested rather than as documents sent to the
    # client.  The same rules about trailing "/" apply to ScriptAlias
    # directives as to Alias.
    #
    ScriptAlias /cgi-bin/ "/var/www/cgi-bin/"

</IfModule>

#
# "/var/www/cgi-bin" should be changed to whatever your ScriptAliased
# CGI directory exists, if you have that configured.
#
<Directory "/var/www/cgi-bin">
    AllowOverride None
    Options None
    Require all granted
</Directory>

<IfModule mime_module>
    #
    # TypesConfig points to the file containing the list of mappings from
    # filename extension to MIME-type.
    #
    TypesConfig /etc/mime.types

    #
    # AddType allows you to add to or override the MIME configuration
    # file specified in TypesConfig for specific file types.
    #
    #AddType application/x-gzip .tgz
    #
    # AddEncoding allows you to have certain browsers uncompress
    # information on the fly. Note: Not all browsers support this.
    #
    #AddEncoding x-compress .Z
    #AddEncoding x-gzip .gz .tgz
    #
    # If the AddEncoding directives above are commented-out, then you
    # probably should define those extensions to indicate media types:
    #
    AddType application/x-compress .Z
    AddType application/x-gzip .gz .tgz

    #
    # 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

    # For type maps (negotiated resources):
    #AddHandler type-map var

    #
    # Filters allow you to process content before it is sent to the client.
    #
    # To parse .shtml files for server-side includes (SSI):
    # (You will also need to add "Includes" to the "Options" directive.)
    #
    AddType text/html .shtml
    AddOutputFilter INCLUDES .shtml
</IfModule>

#
# Specify a default charset for all content served; this enables
# interpretation of all content as UTF-8 by default.  To use the 
# default browser choice (ISO-8859-1), or to allow the META tags
# in HTML content to override this choice, comment out this
# directive:
#
AddDefaultCharset UTF-8

#
# The mod_mime_magic module allows the server to use various hints from the
# contents of the file itself to determine its type.  The MIMEMagicFile
# directive tells the module where the hint definitions are located.
#
MIMEMagicFile conf/magic

#
# Customizable error responses come in three flavors:
# 1) plain text 2) local redirects 3) external redirects
#
# Some examples:
#ErrorDocument 500 "The server made a boo boo."
#ErrorDocument 404 /missing.html
#ErrorDocument 404 "/cgi-bin/missing_handler.pl"
#ErrorDocument 402 http://www.example.com/subscription_info.html
#

#
# EnableMMAP and EnableSendfile: On systems that support it, 
# memory-mapping or the sendfile syscall may be used to deliver
# files.  This usually improves server performance, but must
# be turned off when serving from networked-mounted 
# filesystems or if support for these functions is otherwise
# broken on your system.
# Defaults if commented: EnableMMAP On, EnableSendfile Off
#
#EnableMMAP off
EnableSendfile on

# Supplemental configuration
#
# Load config files in the "/etc/httpd/conf.d" directory, if any.
IncludeOptional conf.d/*.conf
ServerTokens ProductOnly





Listen 80

# Apache #0 port 80 (default Website)
<VirtualHost *:80>
    DocumentRoot /var/www/www.example.com_80
    ServerName  www.example.com
    ServerAlias example
    ServerAlias apache.example.local
    ServerAlias apache
    ServerAlias www.example.local
    ServerAlias www
</VirtualHost>

# Apache #0 port 443 (default secured Website)
<VirtualHost *:443>
    DocumentRoot /var/www/www.example.com_443
    ServerName  www.example.com
    ServerAlias example
    ServerAlias apache.example.local
    ServerAlias apache
    ServerAlias www.example.local
    ServerAlias www
</VirtualHost>

# IIS #1 port 80 (accessed using Apache port 8080)
<VirtualHost *:8080>
    ProxyPreserveHost On
    ProxyPass / http://iis.example.local/
    ProxyPassReverse / http://iis.example.local/
    ServerName  www.example.com
    ServerAlias example
    ServerAlias apache.example.local
    ServerAlias apache
    ServerAlias www.example.local
    ServerAlias www
</VirtualHost>

# IIS #2 port 8081
<VirtualHost *:8081>
    ProxyPreserveHost On
    ProxyPass / http://iis.example.local:8081/
    ProxyPassReverse / http://iis.example.local:8081/
    ServerName  www.example.com
    ServerAlias example
    ServerAlias apache.example.local
    ServerAlias apache
    ServerAlias www.example.local
    ServerAlias www
</VirtualHost>

# IIS #3 port 8082
<VirtualHost *:8082>
    ProxyPreserveHost On
    ProxyPass / http://iis.example.local:8082/
    ProxyPassReverse / http://iis.example.local:8082/
    ServerName  www.example.com
    ServerAlias example
    ServerAlias apache.example.local
    ServerAlias apache
    ServerAlias www.example.local
    ServerAlias www
</VirtualHost>

# IIS #4 port 8083
<VirtualHost *:8083>
    ProxyPreserveHost On
    ProxyPass / http://iis.example.local:8083/
    ProxyPassReverse / http://iis.example.local:8083/
    ServerName  www.example.com
    ServerAlias example
    ServerAlias apache.example.local
    ServerAlias apache
    ServerAlias www.example.local
    ServerAlias www
</VirtualHost>

# IIS #5 port 8084
<VirtualHost *:8084>
    ProxyPreserveHost On
    ProxyPass / http://iis.example.local:8084/
    ProxyPassReverse / http://iis.example.local:8084/
    ServerName  www.example.com
    ServerAlias example
    ServerAlias apache.example.local
    ServerAlias apache
    ServerAlias www.example.local
    ServerAlias www
</VirtualHost>

# Apache #1 port 8085
<VirtualHost *:8085>
    DocumentRoot /var/www/www.example.com_8085
    ServerName  www.example.com
    ServerAlias example
    ServerAlias apache.example.local
    ServerAlias apache
    ServerAlias www.example.local
    ServerAlias www
</VirtualHost>

# Apache #2 port 8086
<VirtualHost *:8086>
    DocumentRoot /var/www/www.example.com_8086
    ServerName  www.example.com
    ServerAlias example
    ServerAlias apache.example.local
    ServerAlias apache
    ServerAlias www.example.local
    ServerAlias www
</VirtualHost>

# Apache #3 port 8087
<VirtualHost *:8087>
    DocumentRoot /var/www/www.example.com_8087
    ServerName  www.example.com
    ServerAlias example
    ServerAlias apache.example.local
    ServerAlias apache
    ServerAlias www.example.local
    ServerAlias www
</VirtualHost>

# Apache #4 port 8088
<VirtualHost *:8088>
    DocumentRoot /var/www/www.example.com_8088
    ServerName  www.example.com
    ServerAlias example
    ServerAlias apache.example.local
    ServerAlias apache
    ServerAlias www.example.local
    ServerAlias www
</VirtualHost>

That's a lot of config to be testing all at once, might be good to trim it down to starting with just one thing, like the 8080 listener. Which config is actually in use there - the hardcoded IP or the DNS name? (if it's the IP, I'm guessing the `192.168.11.2`/`192.168.1.2` difference is just a typo when posting?) Anything useful in the Apache error logs? Are you able to run a packet capture on the Apache system to see exactly what it's doing? — Shane Madden, Mar 28 '13 at 06:45
Yes, the 11.2 and 1.2 is a typo. It's a moot point, because I opted for the DNS name. — Willscrlt, Mar 28 '13 at 07:18
As to the logs... I am more used to the Debian/Ubuntu log layout. I'm running on Fedora 18 now. Nothing particularly helpful in the logs. 80 looks just normal, and the others don't even show up. I can't find all of the logs I'm used to seeing (maybe they are combined?). So, any suggestions as to specifically where to look (at least which logs) would be helpful. Not sure how to "run a packet capture on the Apache system". Do you know if mod_proxy requests should show up in the access.log file or somewhere else? — Willscrlt, Mar 28 '13 at 07:21
I updated the example above to show my actual code. The relevant portions are waaaay down at the bottom. — Willscrlt, Mar 28 '13 at 07:32
You should use something like the developer tools in Chrome or firebug on Firefox to see what is going on between your browser and the server. It is quite possible that there is something on your iis server that is breaking the proxy. For example, if the IIS sends a redirect to itself that is not caught by the ProxyPassReverse directive on your apache server you might run in exactly this timeout situation... — Krist van Besien, Mar 28 '13 at 08:14

How to reverse proxy specific ports to a different server behind a firewall using Apache mod_proxy

0 Answers0