Reverse Proxy Server 2: SVN3 over https

From The Uniform Server Wiki
Jump to navigation Jump to search

 

Uniform Server 5.0-Nano
Reverse Proxy.

How to configure proxy server to run a subversion server over https.

On the previous page I covered how to proxy our SVN back-end server over http. As a prerequisite to securing SVN this page looks at how to proxy this SVN back-end server over https.

It also shows how to resolve Bad Gateway error message this is a consequence of going from https (front-end server) to http (back-end server).

I have assumed you are following this tutorial and have the test servers in place.

Server certificate

If you have no already done so create a new server certificate for the proxy server as follows:

  • Run server_a
  • Left click tray icon select Advanced > Server certificate and key generator
  • Press Enter at all prompts

This creates an new server certificate and key pair, in addition enables https in Apache's configuration file.

Top

Edit configuration file

Running SVN over https is similar to http and uses identical code; only difference is where that code is located.

Edit file C:\server_a\UniServer\usr\local\apache2\conf\ssl.conf

Add the following code:

ProxyPass /svn/ http://localhost:83/svn/
<Location /svn/ >
  ProxyPassReverse /svn/
   <Limit OPTIONS PROPFIND GET REPORT MKACTIVITY PROPPATCH PUT CHECKOUT MKCOL MOVE COPY DELETE LOCK UNLOCK MERGE>
     Order Deny,Allow
     Allow from all
     Satisfy Any
   </Limit>
</Location>

The code is placed almost at the end of the file just above </VirtualHost> as shown below

#== Most problems of broken clients are related to the HTTP
# keep-alive facility. Disable keep-alive for those clients.
SetEnvIf User-Agent ".*MSIE.*" \
         nokeepalive ssl-unclean-shutdown \
         downgrade-1.0 force-response-1.0

ProxyPass /svn/ http://localhost:83/svn/
<Location /svn/ >
  ProxyPassReverse /svn/
   <Limit OPTIONS PROPFIND GET REPORT MKACTIVITY PROPPATCH PUT CHECKOUT MKCOL MOVE COPY DELETE LOCK UNLOCK MERGE>
     Order Deny,Allow
     Allow from all
     Satisfy Any
   </Limit>
</Location>

</VirtualHost> 

Test

Purpose of this test is to check configuration and demonstrate Bad Gateway error message.

  • Start server_a
  • Start server_c
  • Type https://localhost/svn/

Result: Collection of Repositories page displayed, click the link myproject or whatever you named your repository and have a browse.

SVN client:

Use your SVN client, confirm you can checkout a working copy, make a few changes and confirm you can commit these to the repository.

Using your client either copy or move a file within the repository you will receive a Bad Gateway error message e.g.

Error: Error while performing action: COPY of ../perl/Run.bat: 502 Bad Gateway (https://localhost)

Top

Headers

You will have noticed most subversion operations work through the proxy. However operations such as COPY or MOVE for both files and directories fail with error Bad Gateway.

Reason for this, DAV requests such as COPY and MOVE use header Destination information that contains the full target path of the operation. Since we are going from HTTPS to HTTP it looks as if the operation is for a different machine (server) that does not exist hence bad gateway error (it cannot find a back-end server https://).

Interestingly mod_dav validates only the scheme and not host-name this makes the solution a one liner. Add this line

RequestHeader edit Destination ^https://(.*)$ http://$1

It translates the destination header from https to http thus keeping DAV happy

Edit file: C:\server_a\UniServer\usr\local\apache2\conf\ssl.conf add the line above location as shown below:

RequestHeader edit Destination ^https://(.*)$ http://$1
ProxyPass /svn/ http://localhost:83/svn/
<Location /svn/ >
  ProxyPassReverse /svn/
   <Limit OPTIONS PROPFIND GET REPORT MKACTIVITY PROPPATCH PUT CHECKOUT MKCOL MOVE COPY DELETE LOCK UNLOCK MERGE>
     Order Deny,Allow
     Allow from all
     Satisfy Any
   </Limit>
</Location>

Top

Test 2

Repeat avove test.

  • Start server_a
  • Start server_c
  • Type https://localhost/svn/

Result: Collection of Repositories page displayed, click the link myproject or whatever you named your repository and have a browse.

SVN client:

Use your SVN client, confirm you can checkout a working copy, make a few changes and confirm you can commit these to the repository.

Using your client either copy or move a file within the repository this time you will not receive a Bad Gateway error message e.g.

Top

Summary

The above shows how to proxy an SVN server over https, there are no restrictions this allows all users access with the ability to manipulate repositories.

On the next page I cover restricting access.

Top


Uc small logo.gif Ric