After some Googling, I discovered that Android has the ability to read vCards encoded in a QR Code. The downside to this is that vCard is a fairly verbose format and you burn up bytes rather quickly. A high byte count QRcode is difficult to fit in a usable size on a US standard 2″x3.5″ card. qrstuff claims to have a work around for this by just encoding a HTTP URL. I tried this myself (not using the qrstuff service) and it did not work for me under Android 2.2 on my Droid2 (2.3.20). Experimentally, it seems that an encoded vCard stripped down to only a couple of entries is feasible.

I created the QR codes for the back of my new business cards using the qrencode package and then did the layout of the card using Gimp. It would probably have been better to use a package better suited to page layout like Scribus but I was in hurry to get the cards in time for SCALE10x and didn’t want to learn a new package. This is the Makefile I used to generate the QR code images.

all: jhoblitt_vcf.png jhoblitt_linkdin.png

jhoblitt_vcf.png: jhoblitt.vcf
cat jhoblitt.vcf | qrencode -l L -s 16 --margin=4 -o jhoblitt_vcf.png

jhoblitt_linkdin.png:
qrencode -l L -s 27 --margin=4 -o jhoblitt_linkdin.png "http://linkd.in/jhoblitt"

clean:
rm jhoblitt_vcf.png jhoblitt_linkdin.png

The -s flag is the number of pixels in the output image to use to present a QR code pixel. The values I used were from trial and error trying to get the output image as close to 900x^2 as possible. Since the number of pixels in a QR code depends on the number of bytes being encoded, this value needs to be adjust based on the input. I then scaled the images to 900px square with the intent (hope?) that the card printer I used (uprinting.com) will be printing at 600dpi. I would have preferred to use WHCC, as I trust their color management, but they couldn’t guarantee me a 1 day production window needed to get the cards by Wednesday and I leave for SCALE10x on Thursday.

Here are the finished results. The versions used for printing are 2100x * 1200px.

username: configuration
password:
(password is blank)

username: information
password:
(password is blank)

Many version of the BMC include a java console redirect applet that *does not* work with 64bit JVM on Linux.

Every SM board I’ve touched has used the same default user/passwd.

username: ADMIN
password: ADMIN

Known to be the default password for Raritan PX-5000 series (Outlet Metered, Outlet Switched) models:

• DPXR20A-20L6
• DPXR20A-30L6

I created a child theme of Yoko to tweak a few things for this blog. My theme is named YokoGeek and a list the tweaks I’ve made are in the README. I’m completely open to merging features for technical blogging into YokoGeek; patches welcome.

Verbatim from the post:

Host */*
ProxyCommand ssh $(dirname %h) nc -w1 $(basename %h) %p

This is pretty slick in that you can bounce through an arbitrary number of hosts. eg.

ssh 1sthost/2ndhost/3rdhost

This method isn’t perfect, and while there are some good comments at the bottom of the blog post, I believe there are a few problems that aren’t fully fleshed out in the discussion. If you have different usernames on the systems you want to proxy through, this approach is going to run into trouble. The first ssh hop can get the correct username from the command line as in ssh @... but after that ssh defaults to using $USERNAME. Ideally, one could somehow specify the username for each subsequent hop. Perhaps something like:

ssh foo.example.com/a@bar.example.com/b@baz.example.com/...

However, ssh splits [user@]hostname input into a remote login username part (%r) and a target host name part (%h). The splitting is done on the right most @ and this can lead to the %h no longer being matched by Host */*. eg.

ssh foo@bar.example.com/baz@quix.example.com

Would get parsed as:

%r = foo@bar.example.com/baz
%h = quix.example.com

Since %h does not contain a / at this point, it will not match Host */*. One ugly thing that could be done is change the match to Host * and to make sure this directive stays at the very bottom of the configuration file. Then the original ssh argument could be recreated with %r@%h. At which point you would need to do your own host separator parsing. This approach is highly undesirable because the Host * rule will match any hostname not matched in the configuration file. The more obvious thing to do here is to replace the remote login username separator with another meta-character. This is what the first comment on the post tries to do:

Vincent Bernat Says:
2009-04-10 00:51:16+0200

Here is an “enhanced” version:

Host */*
ProxyCommand ssh ${$(dirname %h)/\%%/@} nc -w5 ${$(basename %h)#*%%} %p

You can specify the login for each hop with “%” instead of “@”.

Which is probably the correct general idea but this syntax won’t work under bash parameter expansion. Comment #6 suggests that this does work under zsh but I’m not generally a zsh user, nor is zsh as commonly installed as bash/ssh/nc. Even if this did work under bash, it would be more convenient to not have to specify data that’s already contained in the ssh client config file. As far as I can tell, there is no way to accomplish this with a recursively matching Host directive as %r will always be the string that was matched when ssh was first invoked. It looks like the only solution would be to write some code that can parse the the ssh config and pull out the appropriate username for each hop in the proxy chain.

The second issue is with the -w1 argument to netcat. Which tells it to disconnect if the connection is idle for one second. Unless your only executing remote commands, this value is probably too short. It needs to be at least >= ServerAliveInterval and probably more like >= ServerAliveInterval * ServerAliveCountMax. A wait timeout shouldn’t be needed at all as a broken ssh connection will kill off the associated shell, which should terminate the netcat invocation. The -w[n] param can just be removed.

If anyone knows a working solution to the the username issue, please let me know.