DevHeads.net

Postings by Niki Kovacs

Problem with Digikam and libgphoto2 after latest update

Hi,

I have CentOS 7 with KDE on my workstation. I'm using the CR repo. I had
to remove Digikam to be able to do the latest update (1 GB of updates...
wow).

XScreenSaver

Hi,

I'm currently moving all our local school's desktop clients from
Slackware 14.1 to CentOS 7 + Xfce. Right now I'm fine-tuning the default
user profile.

I have a problem with XScreenSaver. The application per se works very
well. Only there's a hard-coded pop-up window that reminds the user that
he's not running the latest version. So, if I'm running version 5.36 as
provided by the EPEL repo and not the latest and greatest 5.38 as
provided upstream, I get a pestering pop-up window informing me that
YOUR VERSION OF XSCREENSAVER IS VERY OLD.

CentOS 7 + Xfce + GDM : disable "switch user" ?

Hi,

I have CentOS 7 + Xfce + GDM installed on all our local school's desktop
clients.

I'd like to disable the "switch user" menu entry, since our desktop
clients have a relatively limited amount of RAM. Most users tend to use
the "switch user" functionality to log off, and at the end of the day,
the computer has no RAM left.

I know there is a way to disable this functionality, I vaguely remember
having it done a few years ago on Slackware.

Any suggestions ?

Niki

How insecure is NIS ? Possible alternatives ?

Hi,

In the past I've setup simple centralized authentication with NIS and
NFS, without bothering about possible security implications.

Over the next month I have to setup a new network in a local school, and
I wonder if I should use NIS/NFS. I still have my own documentation,
it's simple and somewhat bone-headed to setup, and it just works.

RHEL/CentOS 7 still provide NIS, and I vaguely wonder how exactly it is
insecure. So I thought I'd simply ask on this list.

I know there's FreeIPA available.

Install CentOS 7 over serial port on router board ?

Hi,

I have to install CentOS 7 for a client, to act as cache & filtering
proxy using Squid.

I'd like to use this piece of specialized hardware :

<a href="http://store.calexium.com/fr/systeme-pre-assemble/869-systeme-pre-assemble-rackmatrix-apu-amd-gx-412tc-quatre-coeurs-1-ghz.html" title="http://store.calexium.com/fr/systeme-pre-assemble/869-systeme-pre-assemble-rackmatrix-apu-amd-gx-412tc-quatre-coeurs-1-ghz.html">http://store.calexium.com/fr/systeme-pre-assemble/869-systeme-pre-assemb...</a>

There is no VGA or HDMI video output, just a serial port to connect to,
and then three NICs and two USB ports.

I've never installed CentOS over a serial console, so I don't even know
if it's possible in the first place. Has anyone ever done something like
that ?

Any suggestions ?

Niki

Squid + SquidGuard : static block page not working

Hi,

I've been working with Squid + SquidGuard for a few years, though only
on Slackware.

Squid vs. iptables redirection: exception for certain domains ?

Hi,

I'm currently facing a quite tricky problem. Here goes.

I have setup Squid as a transparent HTTP+HTTPS proxy in my local
network. All web traffic gets handed over to Squid by an iptables script
on the server.

SELinux breaks Squid's ssl_crtd helper

Hi,

I've setup a transparent HTTP+HTTPS proxy on my server running CentOS 7,
using Squid.

Squid and HTTPS interception on CentOS 7 ?

Hi,

I've been running Squid successfully on CentOS 7 (and before that on 6
and 5), and it's always been running nicely. I've been using it mostly
as a transparent proxy filter in school networks.

So far, I've only been able to filter HTTP.

Do any of you do transparent HTTPS filtering ? Any suggestions, advice,
caveats, do's and don'ts ?

Cheers from the snowy South of France,

Niki

Going back to a minimal system : strange problem

Hi,

Some time ago I wrote a little script elaguer.sh ("élaguer" means "to
prune") which simply removes all packages that are *not* part of a
minimal installation.

First I created a list of packages that make up a minimal CentOS
installation. On a fresh install, I would do something like this:

# rpm -qa --queryformat '%{NAME}\n' | sort > minimal.txt

Here's the resulting list of packages. I added a comment on top:

<a href="https://github.com/kikinovak/centos-7-server-lan/blob/master/config/pkglists/minimal.txt" title="https://github.com/kikinovak/centos-7-server-lan/blob/master/config/pkglists/minimal.txt">https://github.com/kikinovak/centos-7-server-lan/blob/master/config/pkgl...</a>

And here's the script to prune the installation, e. g.

Set LANG on CentOS 6 server

Hi,

I'm having a weird problem on a CentOS 6 server. I installed the machine
in french, so I have LANG=fr_FR.UTF8 defined.

I'd like to define en_US.UTF8, because some output is better readable in
english, like chkconfig --list.

I replaced fr_FR.UTF8 in /etc/sysconfig/i18n and /boot/grub/grub.conf.
Unfortunately, when I reboot the system, I still get this:

# echo $LANG
fr_FR.UTF-8

Any suggestions?

Niki

Slightly OT : newsletters, mail formatting and netiquette

Hi,

This question is not exactly CentOS-related strictly speaking, but here
goes. I'm running a few newsletter servers for myself and a handful of
clients on public CentOS servers with PHPList.

For the last twenty years or so I've followed the basic rule that mails
should have no formatting whatsoever, only simple text.

Gtkcdlabel + cdlabelgen on CentOS 7 ?

Hi,

I've been using the nifty little application Gtkcdlabel for making CD
and DVD covers since 2005, if I remember correctly. Later versions are
written in Python, and it's a graphical frontend to the cdlabelgen utility.

The application doesn't look very well maintained, since the 1.15
release dates back to 2011. Nevertheless, I've been successfully running
it on Slackware Linux until the latest 14.2 release.

I'm currently trying to install it on CentOS 7, and I'm only having a
partial success, with a showstopper.

CentOS 7 + KDE : post-installation script

Hi,

I just spent two rainy days writing and fine-tuning a post-installation
script for CentOS 7 and KDE.

<a href="https://github.com/kikinovak/centos-7-desktop-kde" title="https://github.com/kikinovak/centos-7-desktop-kde">https://github.com/kikinovak/centos-7-desktop-kde</a>

I've just tested it on three different machines here, and it works quite
nicely. Feel free to give it a spin and make some suggestions.

Cheers,

Niki

Spamassassin vs. SELinux trouble

Hi,

Spamassassin has been working nicely on my main server running CentOS 7
and Postfix. SELinux is activated (Enforcing).

Since the most recent update (don't know if it's related to it though)
I'm getting the following SELinux error.

--8<-----------------------------------------------------------------
SELinux is preventing /usr/bin/perl from 'read, write' accesses on the
file /var/log/spamassassin/.spamassassin/bayes_toks.

***** Plugin catchall (100.

Apache and web content permissions

Hi,

Until a few months ago, when I had to setup a web server under CentOS, I
assigned (I'm not sure about the correct english verb for "chown"ing)
all the web pages to the apache user and group. To give you an example,
let's say I have a static website under /var/www/myserver on a CentOS
server running Apache.

CentOS 7 + NVidia Quadro 2000 graphic card

Hi,

I'm currently trying to install CentOS 7 (desktop) on a Lenovo
workstation with an NVidia Quadro 2000 graphical card.

Normally I know my way around NVidia cards and how to configure them
either using the ELRepo drivers or those downloaded from nvidia.com. I
have written a corresponding article on my blog:

<a href="https://blog.microlinux.fr/nvidia-centos/" title="https://blog.microlinux.fr/nvidia-centos/">https://blog.microlinux.fr/nvidia-centos/</a>

But this time it looks like I have no luck. ELRepo's nvidia-detect
utility detected the 'kmod-nvidia' driver, but installing it gave no
result.

Configure an Out Of Office Reply with Postfix?

Hi,

I'm running a Postfix mail server on CentOS 7 for our local school. Some
users would like to have an out of office reply for the holiday season.
I see there is a little utility called 'vacation', and I wonder if this
is the right tool for the job.

Any recommendations?

Niki

Transferring Thunderbird mail accounts: Windows vs. Linux

Hi,

One of my clients brought me his PC with Windows 7, so I can migrate it
to Linux, e. g. CentOS 7 + KDE. So far I made a backup of all the data,
but I wonder how I can migrate the existing Thunderbird account.

An operation I perform quite regularly is replace an existing Linux
system (Ubuntu, openSUSE, Fedora, whatever) by CentOS. When Thunderbird
is configured, I just backup the whole ~/.thunderbird directory and then
restore it on the new installation, which usually works perfectly. Any
idea if I do this when moving a desktop installation from Windows 7 to
CentOS?

Cheers,

Niki

Firefox Sync Server 1.5 on CentOS 7

Hi,

I'm currently experimenting with setting up my own Firefox Sync Server
on a public server running CentOS 7, following this document:

<a href="https://mozilla-services.readthedocs.io/en/latest/howtos/run-sync-1.5.html" title="https://mozilla-services.readthedocs.io/en/latest/howtos/run-sync-1.5.html">https://mozilla-services.readthedocs.io/en/latest/howtos/run-sync-1.5.html</a>

So far I have a partial success. Bookmarks are syncing via the basic
internal server running on port 5000, and I can also configure a MySQL
database for bookmark storage.

Accidentally removed sync system user

Hi,

As the subject says, I accidentally removed the 'sync' system user.

CentOS 7 not shutting down correctly

Hi,

I have CentOS 7 with KDE installed on my workstation. Sometimes - like
just now - the system refuses to shutdown correctly. The problem
appeared since I installed the OpenVAS vulnerability scanner (the one
from EPEL), so I don't know if this is linked.

New CentOS/RHEL group on Facebook

Hi,

There are currently two competing CentOS groups on Facebook. The "main"
group is managed by a small group of autocrats with very unilateral
communication skills.

SpamAssassin vs. SELinux

Hi,

I just installed SpamAssassin on two servers running CentOS 7 and
Postfix. One is my sandbox server for experimenting, the other one is
the server that hosts my company's web site, blog, mail, etc.

So far, SpamAssassin seems to work as expected.

Strange problem with CentOS 7 and guest additions in VirtualBox

Hi,

I'm having a very weird problem with CentOS as a VirtualBox guest. Let
me explain it step by step.

tl;dr: I can install VirtualBox Guest Additions and configure a
fullscreen 1280x1024 graphical resolution on a full install, but not on
a reduced install with a lightweight window manager.

Here's what I did.

1. Install vanilla CentOS 7 with KDE.

2. Boot to reduced 1024x768 resolution.

3. Install gcc, make and kernel-devel.

4. Build VirtualBox Guest Additions.

5. Reboot to full 1280x1024 resolution. ==> perfect

On a vanilla desktop installation, this works perfectly.

yum groupinstall vs. yum group install

Hi,

Is there a difference between 'yum groupinstall' and 'yum group
install'? As far as I can tell,

# yum groupinstall "X Window System"

and

# yum group install "X Window System"

get me the same result.

Just curious.

Niki

Use CentOS to create a bootable Mac OS X DVD from dmg file?

Hi,

Sorry if this is only half-CentOS-related.

In my office, I'm running CentOS on all my systems (server, workstation,
laptop, sandbox PCs). A colleague brought me her MacBook Pro to upgrade
it from OS X 10.5.7 to 10.11.6.

I downloaded the 5.8 GB dmg file and now I wonder how to create a
bootable DVD with this using only Linux tools.

1. Can I simply burn this as a data DVD with K3B?

2.

CentOS 7: changes to php.ini

Hi,

I'm hosting a few web apps like OwnCloud, Wordpress and Dolibarr on
CentOS 7 that require a handful of changes to php.ini. I have to define
some custom values for post_max_size, upload_max_filesize, etc.

I don't know if I'm supposed to edit /etc/php.ini directly or if changes
should be put in a configuration file stub in /etc/php.d.

CentOS, PHP & OwnCloud/Nextcloud: the version dilemma

Hi,

I'm currently experimenting with OwnCloud and Nextcloud on a sandbox
CentOS 7 server. I've been using OwnCloud for the last two years for my
own purposes on a Slackware server, and I'm quite happy with it.

In my humble opinion, every admin who wants to host OwnCloud or
Nextcloud on a RHEL/CentOS server is confronted with a version dilemma.

1. CentOS 7 sports PHP 5.4, which has been officially EOL for quite some
time, but Red Hat will provide security update backports until 2024.
Which is fine.

2.

Block internet access for some users on the LAN ?

Hi,

In our local school we have two servers and roughly 80 clients.