Installation

images will not load (off campus)

images will not load (off campus)

by Richard Bayne -
Number of replies: 8
Greetings,
Recently, I "upgraded" our installation using the live CD. The installation was unremarkable. However, on problems including images, these images do not load to machines off campus though there is no problem with computers within the campus network. I thought that perhaps some firewall on the campus system might be preventing access to the images, but that does not make sense since there was no such trouble with the previous installation. If anyone has a clue to a solution, I would appreciate hearing it.
Thank you.
Richard Bayne
In reply to Richard Bayne

Re: images will not load (off campus)

by Michael Gage -
Hi Richard,

The most likely possibility is that the campus is blocking the port which serves the images.  This is usually set to port 8080.  (This can be adjusted in the global.conf file and in the preferences for the lighttpd server.  )

We use the lighttpd server to serve images since that speeds up response time.

-- Mike

In reply to Michael Gage

Re: images will not load (off campus)

by Richard Bayne -
Hello Mike,
If the campus is blocking the port, how can that be adjusted for in global.conf?
Further, when I look at the address of an example graphic it has an address like
http://butcher.math.howard.edu:81/wwtmp/MATH-006bayne/gif/practice1-41-set0prob14image2.png
so I surmised that the port was 81. Or does this have nothing at all to do with it?
    Bayne
In reply to Richard Bayne

Re: images will not load (off campus)

by Arnold Pizer -
Hi Richard,

The most recent WeBWorK LiveDVD http://webwork.maa.org/wiki/Installing_from_WW2.4.9_Ubuntu10.04.2LTS_Vanilla_LiveDVD does NOT set up lighttdp so the fact that the images are being served from port 81 must mean that you altered the configuration.  Or more lightly, did you update global.conf or just use an old copy? Do a diff between your global.conf and the new global.conf.dist.  That will show you how to back out from using lighttpd.

Using lighttpd is a good idea if you have a slow server and/or large numbers of students but is certainly not required.  But if you have been using it, maybe something changed with Morgan's network.  You could always try port 8080 and see if that works or just don't use lighttpd at all.

Arnie
In reply to Michael Gage

Re: images will not load (off campus)

by Richard Bayne -
Mike,
Are you suggesting that if I were to follow the instructional manual for implementing Optional B (lighttpd) that there is a possibility of solving the problem?
Bayne
In reply to Michael Gage

Re: images will not load (off campus)

by Richard Bayne -
Mike,
OK, I am really confused now. Perhaps I should say that the live dvd was not the latest, but the one that I had which is 9.10.  If I set the port to 8080, there are no images even on the campus network. Also, I am not currently using lighttpd.
What I was asking in my most previous note was whether it was likely that using lighttpd would solve the problem since that is what seemed to be implied in the documentation I was reading and that was what I was going to try this morning. From your recent post though, I do not get the feeling that is going to be successful, but I still may give it a try.
   Bayne
In reply to Richard Bayne

Re: images will not load (off campus)

by Arnold Pizer -
Hi Richard,

If you are doing an install from the LiveDVD, why not use the latest version?

But with any version, if you are not using lighttpd (are you sure you are not?, where did the port 81 in the image url come from?) you don't do any special configuration and just use apache for everything. Apache uses the standard httpd port 80 (which does not have to be specified).  This is the way all the vanilla LiveDVD's are set up.  Using lighttpd will not solve your image problem and it's hard to understand what the problem could be if you are using apache but then you should not be using port 81.

Arnie


In reply to Arnold Pizer

Re: images will not load (off campus)

by Richard Bayne -
Hi Arnie,
Thank you for the suggestion and advice. I changed the port to 80 and things appear to be working properly. If the port was changed from the default to 81, it could only have been done by the installation disk, since I made no changes of that sort. Also, if lighttpd is running, it was done by the installation disk. Perhaps I made a choice for it on some menu and did not realize so.
Thanks again.
Richard
In reply to Richard Bayne

Re: images will not load (off campus)

by Arnold Pizer -
Hi Richard,

I'm happy everything is working.  The  LiveDVD's do not implement lighttpd.  My best guess is that you had an older installation that did use lighttpd (which is a good idea to use) and you used the global.conf file from that installation. Since lighttpd is not running, you got your errors (but you should have gotten them from both inside and outside Morgan).

You can check the lighttpd is not running with the command 
ps -aux
and look that you do not see: /usr/sbin/lighttpd 

Arnie