Some useful gpg commands

I recently ran into a problem with some gpg encrypted file, where the files were encrypted with another key than they were supposed to. Therefore I had to reencrypt them with another key. Every time I run into an unusual task with OpenGPG I find myself banging my head into a wall of useless documentation. Here’s some of the useful commands I found which let me resolve the issue:

First I had to find out what keys the file was actually encrypted with.

gpg --list-packets file.gpg - lists contents of a gpg encrypted package - including the key IDs used for encrypting the file. (The man page is of course less useful, since it only says “List only the sequence of packets. This command is only useful for debugging.” - but I haven’t found another way to do what I want)

% gpg --pinentry-mode cancel --list-packets <file>.gpg 2>&1 - if you only want to see which keys a file is encrypted with. (note, it will list the keys to STDERR, so therefor I added the redirect to STDOUT so I could grep for the key I was looking for)

% gpg -k --keyid-format short and % gpg -k --keyid-format long - There is a long and short format for GPG keys. If you want to see the short or long format for the keyid when listing keys, add the —-keyid-format option.

Note: if you always want to print for instance long format, you could add keyid-format long to ~/.gnupg/gpg.conf

Want to know the fingerprint of the subkeys? Use gpg -K --with-subkey-fingerprint --keyid-format none

A few useful links:

• security - How to check if a GPG encrypted file is encrypted using a specific public key? - Super User
• pgp - How to change the gpg key of the pass password store - Ask Ubuntu

Summing up the CS3 conference 2019

This year started with a visit to Rome and the 5th edition of the CS3 (cloud services for synchronisation and sharing) - a yearly European conference that started as a workshop between Universities, National Research and Education networks and Research Centres in an attempt to exchange experiences in extending traditional storage technologies to the cloud.

This was my second visit to the conference, last time was two years ago, and I worked for the University of Oslo and visited primarily because of my interest in sync and sharing solutions. This time, I visited on behalf of my current company, and I have moved a bit down the stack, and I held a short presentation on how we are building an open source load balancer for our next generation storage clusters. I’m not going to say a lot about my talk, I hope it went OK.

The conference itself is packed with content. It is a single track conference spanning three days, and a total of almost 60 talks - which is a LOT! - I’m just linking to a couple of my favourite talks and a couple of observations.

Opening keynote by Davide Salomoni

• Davide Salomoni from INFN did a great job explaining some of the challenges with the current state of machine learning. Great to see a talk about machine learning that is genuinely interesting and not “hyped” in any ways.

The Magic Pocket - How dropbox is handling large data sets

by Said Babayev and Martin Meusburger This was an interesting talk, because it is always fun to hear about how large companies do operations. It is interesting to hear how they have managed to use SMR-drives in production. We have tried, but gave up, but then dropbox is on an completely different scale than us…

Scaling Tightly Coupled Algorithms on AWS

by Scott Eberhardt While I’m not convinced yet that it is a good idea to run your HPC workloads on Amazon, the talk was mostly about scaling, and that’s what made the talk interesting.

One thing I would love to see at a future conference is more attendees from the nordic countries. There is a lot of exiting things going on here, but I feel we are missing out on a bit of the cooperation that happens between the

Rome is a nice city, but January can be cold, rainy and windy. However, I got a few hours of sightseeing in nice weather on Thursday afternoon before I had to return home. The highlight was definitely seeing the Jackson Pollock exhibition at Complesso Del Vittoriano.

Summary from devopsdays Copenhagen

Last week I visited Devopsdays Copenhagen for the second time (which also happened to be the second time the conference was arranged).

Being part of the organising team for two other nordic devopsdays, it is fun to visit the third one! And one particular thing I like about the current state of the nordic devopsdays is the great overlap between the different organiser teams. It really gives the feeling of being a part of a larger community.

The venue

Last year, they had the conference at a concert hall (which used to be an old stable) - which was a very nice venue, but just a bit too small. This year, they had moved it to a movie theatre, which maybe lacked a bit of charm, but it made that up with lots of space, good seats, good audio/video and good catering. And of course there was popcorn!

The talks

All talks were excellent. Period. It was great to finally see Matty Strattons talk, I have missed a few opportunities to see it before. I also enjoyed Heidi Waterhouse’s talk, and Ken Mugrage did a new talk which was very good – with some real world experience thrown in. Nataliya Remez did a talk about safety which was really interesting. All the Ignites were great this year (probably due to the fact that I didn’t do an ignite).

Multi track conferences

Devopsdays Copenhagen was a multi track conference this time, and I must admin I’m not a big fan of multi-track devopsdays. I can see that it made it possible to put in a couple narrower, more technical talks (I saw a couple of them and they were good) - but it also changes the openspace sessions and the hallway track in some way, when everyone have seen the same talks, we are in some ways on the same level when we come to the open space session, but now it was always the question about “did you see this or that talk?”. I think the openspace sessions are the most important part of a devopsdays conference, and the talks just lead up to that, and give everyone a common ground to stand on.

If I can give some advice to devopsdays organisers, it would be to make the conference a single track conference, even if that means you have to make some very hard choices when it comes to selecting talks.

Ignite karaoke

One of the highlights of the programs were a session with ignite karaokes. Quite a few people had the guts to get up in front of the large audience and do an improvised talk with slides they hadn’t seen before. Great fun and a great success!

Mob programming

Emily Bache did a talk about techical leadership in devops, where she discussed the use of mob programming – and she also hosted two introduction sessions to mob programming, during the open space part of the programs. Attendees had the option to either participate or observe, I chose to observe one of the sessions, and it was very interesting to see how the “mob” became more confident and started to cooperate on solving the problem during the course of the exercise. This is definitely something I want to try at some point.

So long, and thanks for all the #tacops!

Since I have done this two times, I guess it is now a tradition: Me and a few others gathered at the best taco place in Copenhagen: Hija de sanchez after the conference for a round of delicious #tacops. And with that - time to go home! Thanks to the danish organisers for making such an awesome event!