zen.org Communal Weblog

I realized I never posted the interview on here! Here’s me talking to Declan Meehan from EastCoast FM about life, love and digital legacy. Very general interview, but wow it went fast!

Life, Love and Digital Legacy with Elana Kehoe

I walked into the Kirkbride Widener CS lab one day as a second semester freshman, nej, maybe first semester sophomore. Brendan was staring at a VT101 with 4 or 5 VAX/VMS manuals, 4 inch binders each, laying open around him.  With a mean, sarcastic voice he looked up and said something like “history majors have nothing on me”.  Before then I had set myself to try to survive college, as my grades where less then great.

It took a few day, maybe a few weeks, but something clicked. College isn’t meant to be survived.  I remember teaching myself Applesoft Basic on the Apple ][+ as a preteen.  On the Apple ][+ Beagle Bros kept me giggling and kept the docs fun to read.  With help of Brendan, el at, I made it fun.  It all started with a stack of VAX assembly language manuals piled around Mr. Kehoe.  It ended with me getting a most improved student award, then watching him leave Widener without his deserved degree.

B built us a MythTV box, and did a lot of the documenting here. Today P turned on the tv and found that the recording files were there, but were empty.  Now, I’ve only had one cup of tea, so I’m not firing on all cylinders, but something at the back of my mind said “I bet the HD is full.”  And it was. Phew. /deletedeletedelete

I have  a lot of things I have to learn.  I know that B added some channels to the Myth setup a couple weeks ago, and it took him something like 2 hours.  There is going to be a day when I shut down the shuttlecraft (our Myth box), but I want to prolong that as long as possible. We’ve used the Myth interface for so long, it would be strange to move to something else.

Maybe I can teach P Unix, and he can play with MythBuntu?

Day before yesterday I tried to upgrade the Akismet plugin used by our website; it’s what stops spam from appearing all over the place on the blog.

They’d changed their system a bit, to try to encourage more people to pay for their service (no blaming them).  This meant the existing plugin no longer worked, unfortunately.  But maybe it was a sign—I decided to try going without it, to see if we could just use the blog as-is.

Not a chance.  The spam comments started appearing so quickly, I couldn’t believe it.  We’re now giving Akismet $24 for a year’s subscription (they’re open to personal users picking $0, still, but we want them to stay in business, too, or we lose).  But it’s already paid off—since I activated it, their plugin has blocked more than 12,000 spam comments.  Had I not gotten it going, I’d be manually processing every, single, one, of them.

Screw that.

The Internet connection in the hospital can be really picky about what I can and cannot visit for a website.  e.g., anything with an mp3 to play is blocked.  I can see why it’s necessary to do this at a primary/elementary school, but in a hospital?  It has some odd side-effects (again that word), including blocking at least part of what the TweetDeck client for Twitter/Facebook/identi.ca/etc etc etc.

Up until now, I’ve been using an SSH tunnel to be able to have a proxy for Firefox to get around this.  But something this morning made my brain think a little bit further: I’m already bringing up a VPN connection to home in order to be able to do the SSH connection to my home desktop anyway.  So what if I look at using that same desktop as a formal proxy, and not just an SSH tunnel?

I’d forgotten that I have squid running on my Ubuntu desktop anyway, to take advantage of its caching of Web content.  So I logged into home, edited my /etc/squid/squid.conf to make sure the line

http_access allow localnet

was uncommented, and did

sudo restart squid

Since ‘localnet’ is defined earlier via the ‘acl’ setup to include the subnet used for my VPN, it’s pre-destined for exactly this task.

And it works, perfectly!  And all pages come up dramatically faster not only because my connection at home is fast (yay UPC), and because the traffic is LZO-compressed thru the VPN.  It’s also taking advantage of the squid caching so lots of the content is immediately available from the squid server.  And by configuring my laptop to use it as the system-level web proxy (not just in Firefox), it fixed TweetDeck, too.

No more SSHing, now I can just leave it on all the time.

Warning: this appears to make the AdBlock Plus plugin for Firefox unable to actually do its job.  I had to install adzapper on my desktop at home and make squid use it.  I’m running Ubuntu 10.04, which changed the older approach to start scripts to instead do “service” things via “start”, “stop”, and “restart” scripts in /sbin.  So I had to adjust

/etc/init.d/squid

to comment out one line and put in two replacements:

#start "$JOB"
 ( /sbin/stop "$JOB" || true ) > /dev/null 2>&1
 /sbin/start "$JOB" > /dev/null 2>&1

so the adzapper install script, invoked by

sudo apt-get install adzapper

can actually do its job properly.

It would appear I’m waking up here pre-loaded with geek urges. 😀

I had to reinstall Firefox 3.6.15 on my laptop (3.6.16 and 4.0 both crash when presented with a weird SSL certificate from the hospital’s Cisco wireless box).  As I went along trying to figure out a way to avoid the bug, I went with a fresh user profile.  I got my bookmarks via Bookmarks -> Organize Bookmarks… -> Import, pointing it at old profile under

C:\Users\Brendan Kehoe\AppData\Roaming\Mozilla\Firefox\Profiles\ngg032uh.default

But I still had to redo all of my Add-Ons and such.  And later, when I decided I wanted to use Firefox 4.0 most of the time (much faster!), I needed the same list.

My list of must-haves, written down here so I won’t have to make as much of an effort next time I have to do this:

1. FlashBlock
2. AdBlock Plus
3. NoScript
4. QuickProxy
5. BlockSite (to block the hospital wifi server at 1.1.1.1 which has a bad SSL cert causing versions other than Firefox 3.6.15 to crash; this way I can use Firefox 4.0 and keep 3.6.15 independently installed solely to authenticate on the wireless)
6. GreaseMonkey
7. GreaseMonkey user script Allow Password Remembering, which overrides ‘autocomplete=”off”‘.  That attribute appears in the HTML of the hospital’s wireless server authentication page. Without this, I have to manually type in the username and password required to be able to use the hospital’s wireless. This great hack makes it possible for Firefox to retain both and free me from having to type them in constantly.
8. Better Gmail 2
9. DownloadThemAll! (batch downloading)
10. Add to Search Bar (so I can easily add www.google.ie)
11. F.B. Purity

I wonder what I’ve forgotten? 🙂

Are there any I should definitely add?

I’ve got rkhunter installed on our Debian Etch box after a recent break-in on a home machine (long story, the short version involves silliness on my part changing to make my desktop receive incoming SSH connections—and leaving the patrick dummy account with its silly original password).

Every day I was getting two separate messages: one from rkhunter itself complaining

Warning: This operating system is not fully supported!

and the second from the daily cron job of running it, saying

/etc/cron.daily/rkhunter:
lsmod: QM_MODULES: Function not implemented

To hush the first, I edited the /var/lib/rkhunter/db/os.dat file and added the line

156:Debian 4.0 (i386):/usr/bin/md5sum:/bin:

I just read through the /usr/bin/rkhunter script to come up with the right syntax/values for this.

To make the daily cron mail stop, I edited the /etc/cron.daily/rkhunter script and changed the invocation line to redirect stderr to the log file (adding ‘2>&1‘) as well:

$RKHUNTER --cronjob --report-warnings-only --createlogfile /var/log/rkhunter.log > $OUTFILE 2>&1

Fingers crossed this does the trick.

The version of rsync installed with Tiger Mac OS X 10.4.11 isn’t the best … you can followsome great instructions and build the 3.0.6 version instead, getting a bit of a speed boost-up.

Anything to avoid typing commands you already know, and apply patches for changes someone else already did. 🙂

Our LaCie 500GB Mac Mini Hub drive, now a few years old, started a horrid clicking noise recently, and wouldn’t mount. Try as I might, it just kept failing. Crap, we lost everything on it! But a bunch of posts in different places, including the Mac OS X Hints Forum, talked about the power supply causing this sort of problem—and the disk itself is fine.

Elana had the great idea of taking the physical drive out of the LaCie case and putting it in an external drive enclosure. (Cuz I’ve amassed far too much stuff.) And voila, it worked just fine! Now I just need to get a cheap 500GB disk which I can use to mirror the contents of this disk, responding to the harsh reminder of how easy it is to lose vast amounts of data.

Some of which actually matters.

Earlier this year I got a SheevaPlug, a little box with some Flash memory and an ARM processor running Linux. It’s so friggin’ awesome! (Technical term.) My main motivation for getting it, aside from a cool toy, was its much lower power consumption compared to the Mac Mini.

For a few years now our Mini had been doing most of the maintenance efforts for our home network, including: DHCP; DNS; running the No-IP client so I can SSH in via our dynamic DSL connection with its random addresses; acting as a printer server; and work as a local NTP server (still to do). (My email folders were also on the Mini thru an IMAP server, but I’ve moved that onto my desktop for the moment.)

The SheevaPlug is now doing all of it. In particular, I’m finding name lookups for Web browsing is vastly faster than when the Mini was doing the effort.

This list offers the details of what I’ve done to use the SheevaPlug. I’ll add to it (to mirror my local ChangeLog) as we make any other tweaks or fixes. It’s not a lot of effort and the end result is great.

(Note: I still need to finish fixing the formatting of this for readability.)

Accessing the box
After initial power-on, logged in as root with the default password nosoup4u. Then I changed the root password to something I’m used to typing.
General Usability
1. As noted on “SheevaPlug”, edit /etc/dhcp3/dhclient.conf and comment out the the line
   

   #OFF#supersede domain-name-servers 127.0.0.1;

2. Ran dhclient eth0
3. Make sure APT will work by doing: mkdir -p /var/cache/apt/archives/partial
4. Install ntpdate with apt-get install ntpdate.
5. Edit /etc/rc.local and comment out the line
   

   #date 012618002009

   and add

   ntpdate ntp.maths.tcd.ie

6. Edit /etc/hostname and change the name from ‘debian‘ to ‘inara‘.
7. I should note the boot sequence for the SheevaPlug still specifies a different subnet:
   

   Nov 14 13:52:19 inara kernel: Kernel command line: console=ttyS0,115200 mtdparts=nand_mtd:0x400000@0x100000(uImage),0x1fb00000@0x500000(rootfs) rw root=/dev/mtdblock1 rw ip=10.4.50.4:10.4.50.5:10.4.50.5:255.255.255.0:DB88FXX81:eth0:none

8. * /etc/rc.local: Comment out
   #OFF#insmod /boot/fat.ko
   #OFF#insmod /boot/vfat.ko
   and add
   chmod 1777 /tmp /var/tmp
9. Edit /etc/fstab and add the lines
   

   tmpfs /var/log tmpfs defaults 0 0
   tmpfs /tmp tmpfs defaults 0 0

   to make the most frequent activity not actually write anything out to the flash memory. Too many writes to flash can accelerate its demise.

10. Also change the root partition in /etc/fstab to specify noatime to also reduce unnecessary “disk” writes:
    

    rootfs / rootfs rw,noatime 0 0

11. Install wget (to download stuff), sysstat (to see how things are running), and rsync (to download/upload stuff) with : sudo apt-get install wget sysstat rsync
Network Time Support
1. Update the list of packages, then install NTP: sudo apt-get update && sudo apt-get install ntp
2. Edit /etc/ntp.conf and change the server line to be the Trinity College server: server ntp.maths.tcd.ie
3. As suggested on “New Plugger How To”, ran dpkg-reconfigure tzdata
   and selected Europe -> Dublin.
Logging in over the USB serial port
1. Follow the instructions at “Setting Up Serial Console Under Linux”
2. On my desktop (running Ubuntu 9.04), ran
   * On homer:
   sudo /sbin/modprobe -q ftdi-sio product=0x9e8f vendor=0x9e88
   sudo apt-get install cu
   sudo chown uucp /dev/ttyUSB1
   so I can then log into the SheevaPlug over a serial line with
   * sudo cu -s 115200 -l /dev/ttyUSB1
   This is really helpful when you make a typo and the box is no longer getting on your network properly!
Network Connection
1. Edited /etc/network/interfaces and changed it from doing DHCP to a static address:
   

   auto eth0
   #iface eth0 inet dhcp
   # /usr/share/doc/ifupdown/examples for more information.
   iface eth0 inet static
   address 192.168.20.8
   network 192.168.20.0
   netmask 255.255.255.0
   broadcast 192.168.20.255
   gateway 192.168.20.1

DHCP Server
1. Installed the DHCP server with: apt-get install dhcp3-server
2. Copied the /etc/dhcpd.conf file over from the Mini.
DNS Server
1. Install BIND with: apt-get install bind9
2. Edit /etc/bind/named.conf.local and add
   

   options {
   // use this to get faster lookups that we cache:
   forward first;
   forwarders {
   // Eircom:
   // BACKUP plan when DoS attacks hit eircom (2009-09-02)
   159.134.237.6;
   159.134.248.17;
   // as per http://broadbandsupport.eircom.net/ under Broadband Settings:
   // 213.94.190.194;
   // 213.94.190.236;
   // Try going straight to the Netopia box
   // 192.168.20.1;
   };
   allow-query { localhost; 192.168.20.0/24; };
   allow-transfer { localhost; };

   };
   zone “20.168.192.in-addr.arpa” IN {
   type master;
   file “192.168.20”;
   };
   zone “network.home” IN {
   type master;
   notify no;
   file “network.home”;
   };

3. Add files /etc/bind/192.168.20 and /etc/bind/network.home from the Mini.
No-IP Client
1. Get GCC off the CD that comes with the SheevaPlug box in SheevaPlug_Host_SWsupportPackageLinuxHost.zip.
2. Extract gcc.tar.bz2 from it, then extract files from that.
3. Download No-IP.
4. Extract the noip sources; may be in a directory noip-2.1.9-1.
5. Expecting ‘gcc’ and ‘noip-2.1.9-1’ are in the same directory, edit the makefile to have
   

   CC=../gcc/bin/arm-none-linux-gnueabi-gcc -O3

6. Do ‘cd noip-2.1.9-1’ and ‘make’, then copy the binary to /usr/local/bin/noip2.
7. Run “/usr/local/bin/noip2 -C” and answer its questions; you’ll need to have registered on no-ip.com to have a username and password to use with this free client.
8. Create the file /etc/init.d/noip2 using the example at http://www.togaware.com/linux/survivor/No_IP.html.
9. Do “chmod 755 /etc/init.d/noip2” and then “update-rc.d noip2 defaults” so it’ll run when you boot.