Status on multi domain Roller

[Henning Kulander <he...@linpro.no>]

Hi!

I've been working on getting support for multi domains in Roller. I
started out by making an extra servlet to handle requests
to /roller/domain, but after reviewing advice from Max Rudman, I chose
to follow his idea, and create a filter instead. 

So now I have a version of Roller where roller is running under tomcat
on port 8080, if I access localhost:8080/roller/, I get the old
functionality, nothing is changed (in theory at least). In front of
tomcat I have an apache-server with mod_rewrite. Apache is listening to
a virtual domain (blog.testdomain.com), and translating URLs to this
domain into the form
localhost/roller/domain/(service)blog.testdomain.com/(handle). So
blog.testdomain.com/page/testblog would is tranlated to
localhost/roller/domain/page/blog.testdomain.com/testblog. 

In Roller I have added a ServletFilter that filters everything coming
to /roller/domain/, finds the right website in an association table and
forwards the request to the normal servlet in the traditional form
(/roller/page/handle). In addition it creates wrappers for the request
and response. The point of the wrappers is to override URLs and
redirects so the user is not moved back to the main Roller-site
(localhost in my development environment). 

So far, there has been little need to change existing Roller-code. I had
to create a DomainManager to handle the new database tables and their
pojo-implementations. The DomainManager needed to be added to
RollerManager so it can be used like the other managers, and that's
about it actually. But unfortunately the URLs generated throughout
Roller are never sent through encodeURL, so they are not picked up by
the wrappers. This resulted in quite a few changes in velocity macros.
All these changes consists in sending the URL through
pageHelper.strutsUrlHelper(). This in turn calls the encodeURL method in
the wrapper. In addition, SearchServlet and *WeblogCalendarModel needed
to be changed. SearchServlet needs to use another context initializer so
the pageHelper object is available in the velocity scripts,
WeblogCalendarModel needs to call encodeURL on the URLs they create.
This enables all URLs to be rewritten to the
form /roller/domain/(service)/(domain)/(handle) on the way out, so the
user still thinks he is on the domain. In addition, these changes
enables the use of UrlRewriteFilter in Roller, so you can do whatever
magic this can do. I use UrlRewriteFilter to rewrite
the /roller/domain/(service)/(domain)(handle) URLs to the more user
friendly form of http://(domain)/(service)/(handle).

The same thing goes for redirects, like when the user commits a comment.
The redirect is picked up by the wrapper and sent through encodeURL to
translate the URL to the correct form before the user is actually
redirected. 

So what's working right now?
Basically everything a normal blog reader needs,
- Browsing a users blog through back, forward, calendar etc.
- Reading RSS-feeds. 
- Searching int the site (searching all sites does not work right).
- Reading comments in a blog
- Writing comments in a blog
- Having one Roller-website appear in more than one domain with
different handles. 

What doesn't work?
Everything domain specific except the features listed above. 
- Logging in sends the user to the global roller domain (ie. /roller/*) 
- There is no way to add domains, add websites to a domain except 
  hacking directly in (my)SQL. 

What next?
The features we have now is the bare minimum needed to present blogs to
web surfers and have them believe that they are browsing different
domains when they are actually only browsing on one server. This is
useful to us in it self, but we also need a way to configure this
without hacking the database directly, and we need a way to let the user
log in on one domain, and administer his websites on that domain. The
most important thing here is the ability to edit and write entries. 

So that leaves these priorities. 
- Adding a user interface where the administrator can add domains, and 
  put websites into different domains.
- Figure out how to enable login on one domain, and not redirect the 
  user to the global roller domain. 
- At a minimum, enable editing and creation of entries on a domain.
- Enable domain wide search.

We are still very interested in getting these changes upstream
eventually, and we are working hard not to break existing functionality
or add complexity. We are thankful for the feedback we have got so far.

If anybody is interested, I can make my patches available. We are
currently working on Roller 2.1 stable. Once 2.2 is available we will
upgrade our patches to 2.2. 


-- 
Regards,
Henning Kulander
System consultant
Linpro AS - Norway's #1 Linux company

Re: Status on multi domain Roller

[Henning Kulander <he...@linpro.no>]

Hi david!

I have answered your questions below. 

On Wed, 2006-04-05 at 08:51 -0400, David M Johnson wrote:
> > So now I have a version of Roller where roller is running under tomcat
> > on port 8080, if I access localhost:8080/roller/, I get the old
> > functionality, nothing is changed (in theory at least). In front of
> > tomcat I have an apache-server with mod_rewrite. Apache is  
> > listening to
> > a virtual domain (blog.testdomain.com), and translating URLs to this
> > domain into the form
> > localhost/roller/domain/(service)blog.testdomain.com/(handle). So
> > blog.testdomain.com/page/testblog would is tranlated to
> > localhost/roller/domain/page/blog.testdomain.com/testblog.
> 
> Do users ever see the localhost/roller/domain/(service) 
> blog.testdomain.com/(handle) form of URL or is that hidden?

No, this form is hidden from the user using UrlRewriteFilter, so the
user sees blog.testdomain.com/handle instead of the long domain-form.
This is of course a requirement, as the long form would be incredibly
ugly.. :)

> > So far, there has been little need to change existing Roller-code.  
> > I had
> > to create a DomainManager to handle the new database tables and their
> > pojo-implementations. The DomainManager needed to be added to
> > RollerManager so it can be used like the other managers, and that's
> > about it actually. But unfortunately the URLs generated throughout
> > Roller are never sent through encodeURL, so they are not picked up by
> > the wrappers. This resulted in quite a few changes in velocity macros.
> > All these changes consists in sending the URL through
> > pageHelper.strutsUrlHelper(). This in turn calls the encodeURL  
> > method in
> > the wrapper. In addition, SearchServlet and *WeblogCalendarModel  
> > needed
> > to be changed. SearchServlet needs to use another context  
> > initializer so
> > the pageHelper object is available in the velocity scripts,
> > WeblogCalendarModel needs to call encodeURL on the URLs they create.
> > This enables all URLs to be rewritten to the
> > form /roller/domain/(service)/(domain)/(handle) on the way out, so the
> > user still thinks he is on the domain. In addition, these changes
> > enables the use of UrlRewriteFilter in Roller, so you can do whatever
> > magic this can do. I use UrlRewriteFilter to rewrite
> > the /roller/domain/(service)/(domain)(handle) URLs to the more user
> > friendly form of http://(domain)/(service)/(handle).
> 
> Why do you need URLs to pass through encodeURL? Is that the "hook"  
> you use to transform URLs?

Yes, the only way I have found to do URL-translation is to use
encodeURL, this seems to be a standard way, and it is what
UrlRewriteFilter uses. The problem with translation is that you need to
know what's a URL, and what's not a URL. You could parse the generated
HTML and try to figure it out, but it's a lot cleaner to call encodeURL
and just override that method. 

> Now that you are calling encodeURL for all URLs, are you seeing a  
> jsessionid on every URL created by Roller?

Nope, just on some of them. I haven't seen anything that leads me to
think that it appears more or less often than before. Doing a quick
check on a rendered page here only shows this on the login link...

> > What doesn't work?
> > Everything domain specific except the features listed above.
> > - Logging in sends the user to the global roller domain (ie. / 
> > roller/*)
> > - There is no way to add domains, add websites to a domain except
> >   hacking directly in (my)SQL.
> >
> > What next?
> > The features we have now is the bare minimum needed to present  
> > blogs to
> > web surfers and have them believe that they are browsing different
> > domains when they are actually only browsing on one server. This is
> > useful to us in it self, but we also need a way to configure this
> > without hacking the database directly, and we need a way to let the  
> > user
> > log in on one domain, and administer his websites on that domain. The
> > most important thing here is the ability to edit and write entries.
> >
> > So that leaves these priorities.
> > - Adding a user interface where the administrator can add domains, and
> >   put websites into different domains.
> > - Figure out how to enable login on one domain, and not redirect the
> >   user to the global roller domain.
> > - At a minimum, enable editing and creation of entries on a domain.
> > - Enable domain wide search.
> >
> > We are still very interested in getting these changes upstream
> > eventually, and we are working hard not to break existing  
> > functionality
> > or add complexity. We are thankful for the feedback we have got so  
> > far.
> >
> > If anybody is interested, I can make my patches available. We are
> > currently working on Roller 2.1 stable. Once 2.2 is available we will
> > upgrade our patches to 2.2.
> 
> 
> How are you managing the new code you've added? Are you using he  
> custom/*.xmlf mechanism or just adding new code into the Roller  
> source tree?

This far I have added things in the source tree, and made the above
mentioned changes in the existing files. If you have any suggestions on
how to do things otherwise, I am willing to consider other ways of doing
it. What's the story behind the custom/*xmlf mechanism?



-- 
Regards,
Henning Kulander
System consultant
Linpro AS - Norway's #1 Linux company

Re: Status on multi domain Roller

[David M Johnson <Da...@Sun.COM>]

I'm glad to hear you are making good progress with this. I have a  
couple of questions in-line below.


On Apr 4, 2006, at 10:07 AM, Henning Kulander wrote:
> I've been working on getting support for multi domains in Roller. I
> started out by making an extra servlet to handle requests
> to /roller/domain, but after reviewing advice from Max Rudman, I chose
> to follow his idea, and create a filter instead.
>
> So now I have a version of Roller where roller is running under tomcat
> on port 8080, if I access localhost:8080/roller/, I get the old
> functionality, nothing is changed (in theory at least). In front of
> tomcat I have an apache-server with mod_rewrite. Apache is  
> listening to
> a virtual domain (blog.testdomain.com), and translating URLs to this
> domain into the form
> localhost/roller/domain/(service)blog.testdomain.com/(handle). So
> blog.testdomain.com/page/testblog would is tranlated to
> localhost/roller/domain/page/blog.testdomain.com/testblog.

Do users ever see the localhost/roller/domain/(service) 
blog.testdomain.com/(handle) form of URL or is that hidden?


> So far, there has been little need to change existing Roller-code.  
> I had
> to create a DomainManager to handle the new database tables and their
> pojo-implementations. The DomainManager needed to be added to
> RollerManager so it can be used like the other managers, and that's
> about it actually. But unfortunately the URLs generated throughout
> Roller are never sent through encodeURL, so they are not picked up by
> the wrappers. This resulted in quite a few changes in velocity macros.
> All these changes consists in sending the URL through
> pageHelper.strutsUrlHelper(). This in turn calls the encodeURL  
> method in
> the wrapper. In addition, SearchServlet and *WeblogCalendarModel  
> needed
> to be changed. SearchServlet needs to use another context  
> initializer so
> the pageHelper object is available in the velocity scripts,
> WeblogCalendarModel needs to call encodeURL on the URLs they create.
> This enables all URLs to be rewritten to the
> form /roller/domain/(service)/(domain)/(handle) on the way out, so the
> user still thinks he is on the domain. In addition, these changes
> enables the use of UrlRewriteFilter in Roller, so you can do whatever
> magic this can do. I use UrlRewriteFilter to rewrite
> the /roller/domain/(service)/(domain)(handle) URLs to the more user
> friendly form of http://(domain)/(service)/(handle).

Why do you need URLs to pass through encodeURL? Is that the "hook"  
you use to transform URLs?

Now that you are calling encodeURL for all URLs, are you seeing a  
jsessionid on every URL created by Roller?


> The same thing goes for redirects, like when the user commits a  
> comment.
> The redirect is picked up by the wrapper and sent through encodeURL to
> translate the URL to the correct form before the user is actually
> redirected.
>
> So what's working right now?
> Basically everything a normal blog reader needs,
> - Browsing a users blog through back, forward, calendar etc.
> - Reading RSS-feeds.
> - Searching int the site (searching all sites does not work right).
> - Reading comments in a blog
> - Writing comments in a blog
> - Having one Roller-website appear in more than one domain with
> different handles.

That sounds like good progress.


> What doesn't work?
> Everything domain specific except the features listed above.
> - Logging in sends the user to the global roller domain (ie. / 
> roller/*)
> - There is no way to add domains, add websites to a domain except
>   hacking directly in (my)SQL.
>
> What next?
> The features we have now is the bare minimum needed to present  
> blogs to
> web surfers and have them believe that they are browsing different
> domains when they are actually only browsing on one server. This is
> useful to us in it self, but we also need a way to configure this
> without hacking the database directly, and we need a way to let the  
> user
> log in on one domain, and administer his websites on that domain. The
> most important thing here is the ability to edit and write entries.
>
> So that leaves these priorities.
> - Adding a user interface where the administrator can add domains, and
>   put websites into different domains.
> - Figure out how to enable login on one domain, and not redirect the
>   user to the global roller domain.
> - At a minimum, enable editing and creation of entries on a domain.
> - Enable domain wide search.
>
> We are still very interested in getting these changes upstream
> eventually, and we are working hard not to break existing  
> functionality
> or add complexity. We are thankful for the feedback we have got so  
> far.
>
> If anybody is interested, I can make my patches available. We are
> currently working on Roller 2.1 stable. Once 2.2 is available we will
> upgrade our patches to 2.2.


How are you managing the new code you've added? Are you using he  
custom/*.xmlf mechanism or just adding new code into the Roller  
source tree?

- Dave