The Linux Questions Thread: a bunch of pitfalls, but technically it's possible

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Linux Questions Thread: a bunch of pitfalls, but technically it's possible

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DeaconBlues: Nov 9, 2011

RFC2324 posted:

Just update/set you alias for ls to ls -v for convenience.

Will do, along with colour settings and - - group-directories-first.

# ? Jun 16, 2016 03:04

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# ? May 29, 2024 02:26

Odette: Mar 19, 2011

I found out about the ls -v thing when I was working on a side project to generate EPUB documents. When I would create the table of contents, the order would be as shown as like ls instead of natural sorting. Ended up having to pad the title IDs so that they would appear correctly. Bit frustrating, but it was quite an interesting turn of events.

# ? Jun 16, 2016 03:19

Saukkis: May 16, 2003; Unless I'm on the inside curve pointing straight at oncoming traffic the high beams stay on and I laugh at your puny protest flashes.
I am Most Important Man. Most Important Man in the World.

Odette posted:

I found out about the ls -v thing when I was working on a side project to generate EPUB documents. When I would create the table of contents, the order would be as shown as like ls instead of natural sorting. Ended up having to pad the title IDs so that they would appear correctly. Bit frustrating, but it was quite an interesting turn of events.

It's still better to use padding than rely on natural order, because you can't be sure what applications support it. I've run to this issue most often with comic book scans. Windows Explorer may show the files in natural order, but what ever picture viewer you have may use lexical order and you have your pages in wrong order.

# ? Jun 16, 2016 17:45

IAmKale: Jun 7, 2007; やらないか; Fun Shoe

I just read that Dell has PPAs that come installed on the Developer Edition of their XPS 13s. Does anyone have a list of those PPAs? I'm using Ubuntu 16.04 on a month-old XPS 15 and I'm wondering if the PPAs have drivers or whatnot that'll help bring the last bit of stability to my machine.

# ? Jun 16, 2016 18:24

tuyop: Sep 15, 2006; Every second that we're not growing BASIL is a second wasted; Fun Shoe

Man, this issue has very little documentation or I'm not phrasing it correctly. Appstreamcli is stopping me from completing an apt-get update correctly. An iPad photo of the issue:

Running apt-get dist-upgrade twice, as a forums post suggested, resolves nothing. Any ideas?

# ? Jun 17, 2016 05:21

Odette: Mar 19, 2011

Are you running an Ubuntu Live CD or something? Just want to get that out of the way first.

# ? Jun 17, 2016 08:21

Vulture Culture: Jul 14, 2003; I was never enjoying it. I only eat it for the nutrients.

Using an LIO iSCSI target, is it possible for me to view all initiators logged into a target/TPG/LUN?

# ? Jun 17, 2016 09:49

tuyop: Sep 15, 2006; Every second that we're not growing BASIL is a second wasted; Fun Shoe

Odette posted:

Are you running an Ubuntu Live CD or something? Just want to get that out of the way first.

Well, a persistent USB install, done through unetbootin on a Mac. Would it have been better to manually create the partitions and stuff?

# ? Jun 17, 2016 18:26

other people: Jun 27, 2004; Associate Christ

Anyone here have experience with which to recommend TV capture software? I bought a USB capture device and hope to use it with Kodi. Kodi relies on the system with the capture hardware running one of these backends:

Tvheadend
VDR
MythTV
DVBLink

I've at least heard of MythTV, but Tvheadend looks nice too.

I don't think I want to do anything fancy, just have a DVR type setup for OTA TV.

# ? Jun 17, 2016 23:23

Lightning Jim: Nov 18, 2006; Just a mad weather-ologist

Anyone taken the Linux Foundation certs?
I've had a co-worker take the LFCS and it seems like an easier to physically take version of the RHCSA in that you can take it from anywhere with just a computer that has a webcam (so yes, you can be spied upon).
The criteria looks virtual identical between the two, of them two.

# ? Jun 18, 2016 20:59

evol262: Nov 30, 2010; #!/usr/bin/perl

It's not hard to find a place to take the RHCSA.

Think of it this way: certs are basically a way to get your CV more attention. They don't serve that purpose if you need to explain to the recruiter that "this cert you've never heard of is basically an RHCSA, except I didn't have to leave my house!"

If you want to prove you know something, interview. If you want it to tick a checkbox for a job, get a recognized cert.

# ? Jun 19, 2016 01:25

HPL: Aug 28, 2002; Worst case scenario.

I'm pretty sure my MCSA helped me get my current job. I'm at a Microsoft-heavy company now and the existing employees are all busting their butts to work their way through Microsoft certification hell. I was able to get it done because I was able to jam on studying full time, all-day, everyday. I can't imagine getting it done with any type of efficiency while working full-time.

But yeah, if I wanted to get a Linux cert, Red Hat would be the way to go. Red Hat is pretty much the standard as far as I can tell. A fancy cert is no good if no one knows about it. Certs are for getting the attention of HR, not operations.

HPL fucked around with this message at 04:24 on Jun 19, 2016

# ? Jun 19, 2016 04:21

Gucci Loafers: May 20, 2006; Ask yourself, do you really want to talk to pair of really nice gaudy shoes?

I don't know what's going on in the Linux Community but there are a few Linux System Administration certifications from various organizations. It's weird but in all honesty the RHCSA not only is the most recognized it's worth it's weight.

# ? Jun 19, 2016 22:55

tuyop: Sep 15, 2006; Every second that we're not growing BASIL is a second wasted; Fun Shoe

So I made an Ubuntu live persistent USB and I now want to create an image and image other USBs to be the same. However, my tests don't allow the imaged USBs to boot on either pcs or macs, my cursory googling suggests that I have to reconfigure the bootloader on the imaged disks. What should I google to fix this? I can't find much so far.

As an aside, how is it done in mass production? You can buy those Ubuntu live USBs and I assume they're just imaged in huge batches, but they still boot?

# ? Jun 20, 2016 04:56

Methanar: Sep 26, 2013; by the sex ghost

Can't you just use dd?

dd if=/dev/sdb of=/dev/sdc bs=1M

Where sdb is your existing stick and sdc is your blank stick.

# ? Jun 20, 2016 05:13

tuyop: Sep 15, 2006; Every second that we're not growing BASIL is a second wasted; Fun Shoe

Methanar posted:

Can't you just use dd?

dd if=/dev/sdb of=/dev/sdc bs=1M

Where sdb is your existing stick and sdc is your blank stick.

I think that's pretty much what I did, except I first created an image with a Mac's diskutil and then dd'd that image onto the stick. I'll fire up my arch stick and try it out as a straight copy from the Linux partition to the new disk.

That might actually be a problem. The original Ubuntu is on a second partition, so that the majority of the USB is available as an exFat partition in Windows computers if I need it. The new disks are slightly larger than the Ubuntu partition, but it's just the whole stick.

# ? Jun 20, 2016 05:31

evol262: Nov 30, 2010; #!/usr/bin/perl

USB stick booting relies on CD-ROM emulation with an eltorito boot section present, which basically says "I'm an emulated hard drive, and here's how you find my bootloader"

dd handles this normally, but you can yank it out with geteltorito (which probably comes with whatever package provides genisofs), then dd that to the disk.

# ? Jun 20, 2016 13:11

tuyop: Sep 15, 2006; Every second that we're not growing BASIL is a second wasted; Fun Shoe

Methanar posted:

Can't you just use dd?

dd if=/dev/sdb of=/dev/sdc bs=1M

Where sdb is your existing stick and sdc is your blank stick.

Nah, no dice. Ugh.

# ? Jun 20, 2016 15:32

RFC2324: Jun 7, 2012; http 418

Is there a way to find out who is ssh'd in as root? ie, I run ssh root@contoso.tld, the remote host should know what my username on the originating host is, how would I get this information?

I need this for logging purposes in a script that would be run on the remote host, so it can be slightly complex, as long as it is reliable.

# ? Jun 20, 2016 20:43

Tigren: Oct 3, 2003

RFC2324 posted:

Is there a way to find out who is ssh'd in as root? ie, I run ssh root@contoso.tld, the remote host should know what my username on the originating host is, how would I get this information?

I need this for logging purposes in a script that would be run on the remote host, so it can be slightly complex, as long as it is reliable.

Why would the remote host know the username you're running that command as?

# ? Jun 20, 2016 21:03

RFC2324: Jun 7, 2012; http 418

Tigren posted:

Why would the remote host know the username you're running that command as?

As I recall, its part of the SSH keys setup. The authorized_keys file has the pubkey and the username in it in the annotation section in every setup I have seen, so it would make sense that ssh would pass that information.

I'm not sure that it ever does anything with that info, which is why I am asking. I can always check if it passes it with an ssh -vvv, but I seem to remember seeing it, and that wouldn't tell me if I can pull that info in any way.

The existence of the authorized_principals file seems to confirm that this would be a thing.

# ? Jun 20, 2016 21:30

evol262: Nov 30, 2010; #!/usr/bin/perl

The last field is a comment. It has no bearing on anything.

authorized_principals is for kerberos. You could pull the tickets (if you were using kerberos).

The real way to audit this is to enforce passwordless sudo only, or only give the key to known accounts on known systems (after which you can check /var/log/secure or journalctl or whatever to see what IP they came from).

# ? Jun 20, 2016 21:57

RFC2324: Jun 7, 2012; http 418

evol262 posted:

The last field is a comment. It has no bearing on anything.

authorized_principals is for kerberos. You could pull the tickets (if you were using kerberos).

The real way to audit this is to enforce passwordless sudo only, or only give the key to known accounts on known systems (after which you can check /var/log/secure or journalctl or whatever to see what IP they came from).

Sounds like I can't do it.

The setup is ssh into a jumphost for the DC as yourself, then ssh into the jumphost for the cluster(which has 128 hosts) as root using a known password, and run then ssh into the host/run commands over ssh from there. I wanted a script to simply some of the simple tasks, but with a log of who did it in case something goes wrong. Best I could do is timestamps to we can correlate logins to the jumphost to actions, and thats iffy given how many people will just use screen to keep a login open on the jumphost.

And no, I can't redesign things to be more trackable, sadly.

# ? Jun 20, 2016 22:08

covener: Jan 10, 2004; You know, for kids!

Tigren posted:

Why would the remote host know the username you're running that command as?

(comedy only) identd!

# ? Jun 20, 2016 22:16

evol262: Nov 30, 2010; #!/usr/bin/perl

RFC2324 posted:

Sounds like I can't do it.

The setup is ssh into a jumphost for the DC as yourself, then ssh into the jumphost for the cluster(which has 128 hosts) as root using a known password, and run then ssh into the host/run commands over ssh from there. I wanted a script to simply some of the simple tasks, but with a log of who did it in case something goes wrong. Best I could do is timestamps to we can correlate logins to the jumphost to actions, and thats iffy given how many people will just use screen to keep a login open on the jumphost.

And no, I can't redesign things to be more trackable, sadly.

You can track this with a small pam module. Or a trivial wrapper around ssh which uses "-o SendEnv" (and chain that to the hosts the jump host reaches), then build your auditing around that, if it's an option. Or set ~/.ssh/environment and use PermitUserEnvironment. Or (it's hacky), but ssh used to treat LC_ variables specially and pass them automagically. It still may. So if you set LC_ORIGUSER or something on the jumphost for the DC, this may get passed automatically.

Of course the best solution other than sudo is centralized logging, and a script which can do cursory associations of time->pid from the bastion, then use auditd (or more logs) to track root's actions per-pid. Or an actual, centralized auditing system. PowerBroker is the last one I used, but hopefully somebody can suggest a reasonable, free (or cheaper) alternative.

# ? Jun 21, 2016 04:58

Lightning Jim: Nov 18, 2006; Just a mad weather-ologist

evol262 posted:

It's not hard to find a place to take the RHCSA.

Think of it this way: certs are basically a way to get your CV more attention. They don't serve that purpose if you need to explain to the recruiter that "this cert you've never heard of is basically an RHCSA, except I didn't have to leave my house!"

If you want to prove you know something, interview. If you want it to tick a checkbox for a job, get a recognized cert.

I already have my RHCSA 6. Problem is is that the internal training for RHCE has gone to poo poo and likely won't happen soon, so I'm trying to do a related path to get up my certs. This is all for internal as well as it also helps my current job.

I also live in the middle of Oklahoma so I have to either drive down to Dallas or up to Kansas City, so yes it's difficult to get to a testing center as I'd have to take time out of work to go do it.

# ? Jun 21, 2016 12:12

some kinda jackal: Feb 25, 2003; �
�

Really biting at the chomp for RedHat to open source Ansible Tower. Hope that's not too far away.

Since we're on the subject, poring through my RHCE material now, hoping to take RHCSA in the next two months and then RHCE Q1 2017 depending on when my CISSP falls. I'm a notoriously poor test taker but I'm superb with hands on in a RH environment so I really hope the two balance out and I can make it through these unscathed :haw:

# ? Jun 21, 2016 13:11

evol262: Nov 30, 2010; #!/usr/bin/perl

Lightning Jim posted:

I already have my RHCSA 6. Problem is is that the internal training for RHCE has gone to poo poo and likely won't happen soon, so I'm trying to do a related path to get up my certs. This is all for internal as well as it also helps my current job.

I also live in the middle of Oklahoma so I have to either drive down to Dallas or up to Kansas City, so yes it's difficult to get to a testing center as I'd have to take time out of work to go do it.

Ok, so the middle of OK is one of those places where it's hard to find a testing center. At least an official kiosk. I'd be surprised if somebody didn't offer the exams there, though.

If it's for internal stuff, then there's no difference, though I have to wonder what good a cert does inside an organization if you already have the knowledge.

I'd also suggest the RHCSA/RHCE7 rapid track instead of 6 for a variety of reasons. Not least of which being that the RHCE6 died a year ago. You can't take it anymore.

# ? Jun 21, 2016 13:55

effika: Jun 19, 2005; Birds do not want you to know any more than you already do.

Fedora 24 worked the best out of all the live USBs I made for my new Skylake build. It's a really nice release! Kudos to everyone. :yotj:

Also I think somebody was asking about Skylake integrated graphics 3D performance? My i5 6600k works well enough for mupen64plus. I don't really game much anymore, though.

# ? Jun 21, 2016 23:09

DeaconBlues: Nov 9, 2011

I'm glad fedora 24 is finally out, after the slight delay.

I'm waiting on a Samsung 850 SSD in the post, which is going in my laptop and getting a fedora 24 GNOME install straight on it.

The current laptop SSD is being reappropriated into my desktop PC for dual boot Windows (it's an old OCZ one) alongside fedora 23 Cinnamon, which is currently running on a Samsung 850 SSD.

So I'll have 2 instances of fedora on the Samsung SSD's and Windows for when I occasionally need it (games) on the old SSD.

I'll do a dnf-upgrade on the Cinnamon installation to bring it up to version 24.

# ? Jun 22, 2016 02:50

evol262: Nov 30, 2010; #!/usr/bin/perl

Gnome software can update now. Cinnamon is the gnome3 fork? I can never remember. They may have it...

# ? Jun 22, 2016 04:16

DeaconBlues: Nov 9, 2011

I don't understand what you mean. I just prefer running Fedora GNOME on my laptop and Fedora Cinnamon on my workstation/big screen.

# ? Jun 22, 2016 08:31

evol262: Nov 30, 2010; #!/usr/bin/perl

I mean this.

MATE is the gnome2 update. Cinnamon was started as a fork of gnome3, and may still include gnome-software. I'm not sure. But I'm saying that if it does, you can try upgrading without dnf upgrade.

# ? Jun 22, 2016 13:29

Ashex: Jun 25, 2007; These pipes are cleeeean!!!

I tried figuring out how to do jump host SSH magic and failed miserably. Basically I've got a jump host that I connect to then a bunch of backend servers behind it. I'm attempting to do ssh forwarding so I can hit them with one command and not have to copy my private key to the jump host since it's a single user for everyone.

So far this is what I got working:

code:

Host bastion
    IdentityFile ~/keys/secret.pem
    Hostname 12.3.2.4
    ForwardAgent yes
    User ubuntu
Host backend
    IdentityFile ~/keys/secret.pem
    Hostname 192.168.1.13
    ProxyCommand ssh bastion -W %h:%p
    User ubuntu

This allows me to just enter "ssh backend" and it works. The problem is the backend servers are dynamic and I just want to enter the IP address.

I tried using the dynamic jump host trick but that didn't work since my key isn't being passed to the backend server.

# ? Jun 22, 2016 14:25

taqueso: Mar 8, 2004

I installed Fedora 24 yesterday, on a system with an nvidia 970. When I use a video player, it takes a huge amount of CPU and is still choppy. I tried to play a game and it complained that my OpenGL version wasn't high enough to run. I figured that meant I needed the nvidia binary driver. I installed these packages from http://negativo17.org/nvidia-driver/: nvidia-driver akmod-nvidia kernel-devel

When I rebooted, the resolution was very low while the fedora boot logo was shown. It then gets stuck in a loop of X not starting, waiting for me to press a key, and then trying to restart X. I'm not near the PC right now, I can post the actual error later.

I couldn't figure out how to get to a text console to try and fix it -- ctrl-alt-F1 through F10 didn't get me one. And at that point it was way past my bedtime.

Should I be trying to use the binary driver?

How can I switch to a text console after the system has booted?

What do I need to do to configure X to use the new driver correctly? Last time I did this kind of thing I think I had to hand edit xorg.conf, which I remember being somewhat involved and annoying.

Should I just run Ubuntu if I want this to use this PC as a general purpose desktop with good 3D support? IIRC Ubuntu will just let me switch to proprietary drivers with a few clicks.

# ? Jun 23, 2016 20:02

evol262: Nov 30, 2010; #!/usr/bin/perl

It's really hard to say without logs. nvidia's binary driver is almost always broken until a couple of weeks after Fedora updates.

Do you have ssh access?

# ? Jun 24, 2016 00:53

taqueso: Mar 8, 2004

Yeah, sorry about no logs, was just thinking about it and being annoyed so I posted about it.

I got home from work and had a chance to look at it more. Turned out that I needed to install the package dkms-nvidia.

# ? Jun 24, 2016 01:28

telcoM: Mar 21, 2009; Fallen Rib

Ashex posted:

I tried figuring out how to do jump host SSH magic and failed miserably. Basically I've got a jump host that I connect to then a bunch of backend servers behind it. I'm attempting to do ssh forwarding so I can hit them with one command and not have to copy my private key to the jump host since it's a single user for everyone.

So far this is what I got working:
code:
Host bastion
    IdentityFile ~/keys/secret.pem
    Hostname 12.3.2.4
    ForwardAgent yes
    User ubuntu
Host backend
    IdentityFile ~/keys/secret.pem
    Hostname 192.168.1.13
    ProxyCommand ssh bastion -W %h:%p
    User ubuntu
This allows me to just enter "ssh backend" and it works. The problem is the backend servers are dynamic and I just want to enter the IP address.

I tried using the dynamic jump host trick but that didn't work since my key isn't being passed to the backend server.

So... "bastion" is your jump host, right?

On the jump host, you might need one setting, ~~either in ~ubuntu/.ssh/config or~~ in the host-wide /etc/ssh/sshd_config:

code:

AllowAgentForwarding yes

When you're doing SSH agent forwarding, you need to make sure it's allowed in the sshd side of things, and then tell the ssh client(s) to actually do it. AllowAgentForwarding is for the sshd, ForwardAgent is for the ssh client.

As your SSH public keys are apparently already in place, you should only need a shell alias like this:

code:

alias backendssh='ssh -tA bastion ssh -A'

When you type 'backendssh <IP address>', it will expand to 'ssh -tA bastion ssh -A <IP address>' which should do what you want.

Alternatively, the ProxyCommand trick needs care to apply in your case since your target IPs are dynamic. If all the backend systems that are behind the jumphost have IP addresses like 192.168.1.*, this might work:

code:

Host 192.168.1.*
     IdentityFile ~/keys/secret.pem
    ProxyCommand ssh bastion -AW %h:%p
    User ubuntu

Here, you *don't* override the target hostname with a Hostname directive, so the IP address you specified will get used as %h in the ProxyCommand.

If the username on the backend host needs to be different from the username on the jumphost, just set the jumphost username on the ProxyCommand line itself:

code:

ProxyCommand ssh bastionuser@bastion -AW %h:%p

telcoM fucked around with this message at 16:14 on Jun 24, 2016

# ? Jun 24, 2016 11:30

Ashex: Jun 25, 2007; These pipes are cleeeean!!!

telcoM posted:

ssh wisdom

Ah excellent, that's really good info. I will try it out soon (side tracked by my router bricking mid-upgrade and trying to shoe horn a FON router in as a temp replacement)

# ? Jun 24, 2016 22:22

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# ? May 29, 2024 02:26

YouTuber: Jul 31, 2004; by FactsAreUseless

How do you guys find and install the various missing packages for to pass configuration checks when compiling software? I'm working with Ubuntu and attempting to compile a newer version of network-manager and network-manager-applet since the current version in 16.04 is broken. I launch configure it runs for a bit then spews out missing packages. Tells me to install gio-unix. I apt search; find multiple versions of libgio and install them all. Start configure again and still says missing gio-unix. I go search and find it's in some alphabet soup package.

Is there some way of automating the install of these missing packages? Half the missing packages are renamed in the Ubuntu repository or grouped under some other package so each individual roadblock requires a google search to find the real name.

# ? Jun 25, 2016 02:10

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Linux Questions Thread: a bunch of pitfalls, but technically it's possible

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