Asitis's questions

I just bought a Yubikey 5 NFC and have set it up per their instructions on Ubuntu 19.04. But my preferred use case is to use the key as passwordless option (if it's plugged in; allow access - if it's not; enter password).

I've found some topics on this here and here but both are either not for a Yubikey or not for Ubuntu. And I'm too inexperienced with these things to blindly fiddle with settings as there is a good chance I'd get locked out forever if I do something wrong.

So I know the Yubikey 5 supports passwordless login for Windows, I figure it must be available on Ubuntu somehow, right? Does anyone have a tip for me?

Edit: To give some context to the valid point made below that this setup wouldn't increase security, matter of fact, would lower it: Yes, I know, very true indeed. However in my case I work mostly from my own (secured) home, but am a stickler for very complicated passwords. However it is slowing me down I have to enter a very long password each time my laptop idles too long, so for when I'm at home, I'd like to be able to use just the key, and if I'm away, leave the key at home and just use a password.

Edit2: Thanks to hackerb9's answer and running through the Yubico install steps again I got it to work. Essentially all I did different was to add auth sufficient pam_u2f.so to both /etc/pam.d/gdm-password and /etc/pam.d/sudo instead of @include common-u2f (which would result in auth sufficient pam_u2f.so authfile=/etc/u2f_mappings cue). So essentially just removed authfile=/etc/u2f_mappings cue did the trick. I'm not 100% sure but I think this is due a 'setup conflict' as I set up the key before attempting this.

I've had quite some issues with the sounds after upgrading from 16.04, but I got all to work properly with PulseEffects. The only downside is that now whenever I play any audio (be it mp3, youtube, spotify, some other media), and another sounds (like notification) plays over it, the speakers crackle and pop.

This is mighty annoying as my colleagues all contact me via Skype. I figure this has to do with some configuration of the audio channels, but I cant seem to find the cause. Any ideas?

I'm wondering how to bind the media keys of my laptop to cmus play/pause next/previous. I've tried to use the bind common audioplay player-pause and variance commands to simply try to do what I want.

I can't seem to figure out the correct 'key names' for the media keys, and I'm not sure if cmus will be able to understand them when running in the background. I've found fixes for OS X such as this but I see no ways to make this work on Ubuntu. Is it possible, if so, how?

Upgraded to Ubuntu 18.04, and loving the new design. Though there is one big eyesore since install:

I can't seem to pinpoint where this image comes from. Can anybody tell me where/how to replace it?

I'm running an online store where I can put a variable versiontag to includes JS and CSS as a cachebuster. I. e.

styles.css?v2018_01

Wherein the 2018_01 is the version tag. Now I also have a CLI tool that makes it quick to set like so

mr config:set 'design/head/meta_version_tag' [insert_my_var_here]

And what I want to do is create a Bash alias that sets the variable to the Unix timestamp whenever it is run. I know I can get the Unix timestamp with date +%s.

So I would make an alias like this:

mr config:set 'design/head/meta_version_tag' date +%s

But the CLI interprets the date +%s as a string, rather than getting its output first.

So what I need is an output like this:

mr config:set 'design/head/meta_version_tag' 1519747390

And so my question is; how can I get the output of the unix datestamp in my alias?

First off, I know that the memory usage as displayed in the System Monitor on Ubuntu isn't definitive. I read all the stuff like this. But consider this:

• I have installed Ubuntu 16.04 dualboot on a MacBook Pro as primary OS
• The MBP has 8GiB memory (7,7GiB to be precise)
• Every other day, my laptop chokes up to the point that nothing response and I can only move my cursor with an insane delay of minutes per inch (in other words; complete freeze)

Ever since this happened I keep the System Monitor open, and every time the system freezes is because the memory usage get's up to 99.99%.

I've tried to use commands such as these sync && echo 3 | sudo tee /proc/sys/vm/drop_caches and extensions for Chrome to better manage processes and memory usage. Most of the time I have 5 windows running:

• Chrome browser
• Sublime Text editor
• Nylas mail client
• Spotify
• Terminal window

As I said, I keep a close eye on the memory usage and reboot from time to time when I notice the memory is > 90%, but it happens often that a process (mostly Chrome) has to pull some weight unexpectedly and if that happens, I can sigh, force-quit my machine, and start it again.

Over the course of the day the memory usage seems to grow and grow, and the only way to clear it again is to reboot. On boot, memory usage is usually 40~45% (+- 3,5GiB). At this time I have 4 tabs in chrome, a terminal window, Nylas in the background and spotify, and memory is at 5.5GiB. I already feel the tension for when it's about to choke up again.

The Ubuntu install is pretty clean and fresh; installed it out of the box and didn't do any crazy stuff with it internally; just using it as a regular user.

Now I don't know if this is due the fact that it runs on a MBP and it isn't optimized for it, or that I could tweak the OS to run better on it (i.e. I don't seem to have any swap available), but I think it would be an idea to limit memory usage to say 95% the same way the battery doesn't charge over 90%; to keep from hitting the 100%.

But I'm no power user. I'm also not afraid to dive in the system and tweak stuff (that's why I wanted to use Ubuntu anyway), but at this point I'm not sure where to look for a solution, if there is one anyway. I've read about launching certain processes (like the browser) in containers and limiting those to a certain amount of memory, but I've also read that that is a 'plain stupid idea' because 'it doesn't work that way'.

So, what do I do? I've read these three questions, but no satisfying answer yet.

My current process list for reference:

Edit: At Duncans advise, here is the list of start up processes. As far as I can tell there is nothing too weird about it.

initctl list

indicator-application start/running, process 1923
unicast-local-avahi stop/waiting
update-notifier-crash stop/waiting
upstart-udev-bridge start/running, process 1678
update-notifier-hp-firmware stop/waiting
xsession-init stop/waiting
dbus start/running, process 1687
no-pinentry-gnome3 stop/waiting
update-notifier-cds stop/waiting
gnome-keyring-ssh stop/waiting
gnome-session (Unity) start/running, process 1848
ssh-agent stop/waiting
unity7 start/running, process 1881
upstart-dbus-session-bridge start/running, process 1761
gpg-agent start/running
indicator-messages start/running, process 1884
logrotate stop/waiting
indicator-bluetooth start/running, process 1888
unity-panel-service start/running, process 1851
hud start/running, process 1839
im-config start/running
unity-gtk-module stop/waiting
session-migration stop/waiting
upstart-dbus-system-bridge start/running, process 1764
at-spi2-registryd stop/waiting
indicator-power start/running, process 1889
update-notifier-release stop/waiting
indicator-datetime start/running, process 1894
indicator-keyboard start/running, process 1895
unity-settings-daemon start/running, process 1841
indicator-sound start/running, process 1898
upstart-file-bridge start/running, process 1768
bamfdaemon start/running, process 1753
gnome-keyring stop/waiting
window-stack-bridge start/running, process 1699
indicator-printers start/running, process 1901
re-exec stop/waiting
upstart-event-bridge stop/waiting
unity-panel-service-lockscreen stop/waiting
indicator-session start/running, process 1902

In the start-up apps only flux, GNOME software, Nylas, SSH Key Agent and StackStorage run.

I'm setting up a LEMP stack on Google Compute Engine to run Magento 1.9. I've configured the server with PHP7/Nginx with Ubuntu 14.04. When I run the Magento setup, halfway through it redirects from downloader.php to downloader/ and I get a 403 Forbidden error.

The nginx log then says this: *323 directory index of "/usr/share/nginx/html/" is forbidden.

I've Googled around and came up with some possible solutions like this, but I've checked the www.conf and it seems to listen to php-fpm already. Any ideas on where to look for the cause?

I've got a pesky problem. Since I started using Ubuntu I've been playing around with the theming of it, and now -something- keeps forcing itself on boot. I want to know how to debug it, and/or find the source.

The problem is this: Whenever I boot my laptop the default login-wallpaper and the wallpaper after login is a botched, cut-up/repeated image that (I think) is the result of nitrogen.

I now run the command nitrogen --restore and it fixes the wallpaper. Now when I lock the machine or logout, I see a correct wallpaper. So everything is fine after I once restore the wallpaper.

So it's a small nuisance but it's bothering me nonetheless: What keeps rewriting my desktop wallpaper on boot? How do I find it out?

What I know: Whenever I disable Nitrogen (and enable desktop icons) the correct set wallpaper applies a second after login, but it still keeps the botched login-wallpaper.

What I already tried: Reset Nitrogen, using things like Ubuntu Tweak and commands like these. I feel like I've already tried tons of possible ways to (re)set the greeter wallpaper, but something keeps forcing it on boot.

Now I'm not afraid to dive in the technicals, though I can be considered a Ubuntu-noob (only a few months on the system). How, where and why can I find out what exactly is happening? Like is there a way to print all boot commands in a way that would point me in the right direction? Am I missing something obvious? Whelp!

I'm sure I'm not the only one in this situation: I run Ubuntu 16 on my laptop, and I use that to connect to my workstation in the office.

Now there are a couple things that I have to do every day when I connect to my workstation, such as fixing my bluetooth mouse speed, setting the right resolution for both screens and restoring my wallpaper with nitrogen. For each of these tasks I have a (startup) script which works fine, but when I connect my second screen, the laptop is already booted.

So my question is, next to start-up applications, how could I (i.e.) run nitrogen --restore and scale down the resolution on my laptop (from 2560x1600 to 1440x900) when I connect the second screen?

What I do now is run all seperate scripts again manually, which isn't a big deal, but we don't use Ubuntu to just accept how it is, right? ;)

To clarify; my question isn't too specific for these tasks, but more in a general sense; how could I fire anything from the terminal on specific actions like "input of display detected"?

I'm new to Ubuntu after jumping the OS X ship since Captain Tim is starting to lose it. So I've been trying it on dualboot, and I love it.

But I see some files in my Home folder which I -think- I can delete, but I also know it could implode everything. Can anyone tell me if these files are safe to delete?

• dht.dat
• dht_feed.dat
• Examples
• Release.key
• resume.dat
• rss.dat
• settings.dat

Edit: Well, I moved all files to the trash and since then I experienced several freezes, crashes etc. Which would all be fixed by a (forced) reboot, but they kept happening, so I moved all items back from the trash and so far so good; no more freezes (yet).

So appearantly there is something with these files. How could I debug any errors?