Retrieving passwords with tcpdump

The other night many weeks ago I chose to install Jitsi in one of our streamers.

I log into the OpenStack panel and make a quick resize of the instance.

Midway it barks and doesn’t come up. And nothing I can do from the console or there manages to un-stuck it from that state. So off it goes a ticket to support.

Meanwhile I spin another instance and rebuild the basic services.

In the heat of the night I forgot the set of users and passwords for the ingress streams. They were just there, in a volume attached to a zombie machine that I couldn’t access. And also in a backup disk just a room across, but I forgot about it back then.

Thankfully we got Nginx (and Traefik on the newer boxen) that take care of handling ssl, so inside everything is in the clear. All I had to do was

tcpdump  -n -w dump 'tcp port 8000'

and after a quick run with strings I had all the passwords again.

Making a beam compass

Today was one of those days when in order to do something I say to myself “I need this tool and (especially now) I can not buy nor justify buying it. So let’s build one”.

And that in itself takes more time than the whole project.

I was in the process of fixing an old dentists lamp that was laying around, the fresnel lens was originally held with some tiny and feeble metal strips that were in horrible shape.

Instead of making a replacement with some leftover stock or filler rods I decided to make a proper retention ring with sheet metal from a computer case.

But, my simple compass wasn’t able to make circles as big as I needed. Thus I set to build a beam compass.

I had the hardened points from a couple of broken punches, so it was only a matter of cross drilling some bolts and figuring out how to end up with something that would be useful.

Except from the bolts everything else came from either the rust bucket or the trash.

There are a lot of things that can be improved but as it is, it fulfills its intended purpose just fine:

Pity that it’s already too late to start the plasma cutter and finish this part.

Latest geek reads

Some of the things I’ve read/watched lately to sharpen my skills:

Christmas

The other day we had a Christmas dinner mostly like every previous years.

I’m not very much into receiving physical gifts but sometimes a little thing with a lot of thought can change everything. Long ago a couple of friends collaborated on an anthology of poems and the last weekend it arrived after a convoluted trip from Uruguay.

The result of their hard work is called “¡Dale Hermano! 20 Poetas del Río de La Plata”.

After the traditional toast I drove my grandma home and then went to say hi to a couple of friends.

The night was unusually quiet. After wandering without a clear intention for a while I parked at Parque San Martín and started to read.

The poems did not have the author with them but while reading I could imagine some of my friends reciting those and, upon looking at the index, I was most of the times correct in my guesses.

Thanks Mar and Pachi for such a great night.

¡Dale Hermano! 20 Poetas del Río de La Plata

Power off.

Today I replaced a couple of quick hacks with InfluxDB and Chronograf.

I like things that run without breaking:

# supervisorctl
carbon      RUNNING   pid 1415, uptime 207 days,  19:49:57
graphite    RUNNING   pid 1419, uptime 207 days, 19:49:57
icecast     RUNNING   pid 24419, uptime 32 days, 1:11:18

Boot / No Boot

Today while cleaning I found an old stm32 board carrying an STM32F030F4P6.

Turns out that PlatformIO supports it so just for fun I tried to blink some lights.

I couldn’t find my stlink at home but openocd can use a buspirate as a programmer.

It took a while to upload but after that I was able to launch gdb.

And the light was dead.

Strangely enough poking at the memory showed that the code indeed was there. After a long pause to think I noticed that the boot 0 jumper was misplaced.

The lights flashed and there was much rejoicing.

Tiling

(this has nothing to do with a window manager)

During the last couple of days I was mostly dumb because of the heat. But the nightly breeze gave me a bit of life.

So I started to tile the new bathroom.

I helped many times with this kind of endeavors but this is the first that I’m completely on my own.

The initial bucket of paste yielded around 7 tiles, most of it ended on the floor. But when I finally got the hang of how to use the trowel I managed to put 16 tiles with little waste.

Bathroom tiling

A very apt metaphor

“we don’t have electricity on the south side of the building, but I know water conducts electricity, so just connect the water main to the power grid, then install an outlet in every faucet”

Brad Montgomery on what we do as software engineers. Original at https://bradmontgomery.net/blog/blue-collar-programmer/

I don’t know why or how I ended up at that post but that situation evokes many fond memories of failed attempts at explaining what I was doing sometimes.

For all of its sins (or our inability to understand it back then) XML coupled with XSLT & friends is a nice basis to do ETL transformations.

Carancho.

This morning I went out to run some errands and on my way back I crossed along Parque Saavedra to enjoy the smell and freshness of a rainy morning.

Hopping among the bushes I spotted a big bird (at least compared with what can be usually seen in this part of the city).

Here they go by the name of Caranchos, a term that encompasses many former members of the Polyborus genus, mostly Caracara plancus.

This one let me follow its routine from a very close distance for quite a bit of time.