Category Archives: linux

boot issues, fedora, linux

Upgrading to Fedora 25

Every upgrade is a little easier, as my restore scripts get better. This was probably the easiest in more than a decade.

This earlier post describes how I put the persistent parts of the system onto btrfs subvolumes, so that on a new system I only need to symlink most of the stuff.

I created a usb stick, containing the resore script, a keyfile for the encrypted drive containing the btrfs subvolumes (the drive is encrypted), and the Nvidia driver installer (which I didn’t need). Halted the system, changed to a different boot ssd drive in the 2.5″ removable drawer, and installed onto it from the downloaded Fedora 25 installer.

This time I made the /boot partition much larger, so that I’m not having to clean up old kernels so often.
Continue reading Upgrading to Fedora 25 →

fedora, linux, security, ubuntu

Disabling ipv6

I was really keen to get ipv6, and very pleased when my provider (wretched hateful Comcast) finally gave me an ipv6 address.

What I didn’t know was that most VPN providers, including the one I use, are only tunneling the ipv4 traffic. So if you make a connection to a location that supports ipv6 (has an AAAA record) the connection will completely bypass the vpn tunnel.

I have temporarily turned off ipv6 on the external interface by putting this into /etc/sysctl.conf:

net.ipv6.conf.enp4s1.disable_ipv6 = 1
apache, fedora, linux, website building

Webalizer

I wanted to know what sort of traffic was being generated by the various websites I host.  So I set up webalizer. Every time I decide to use this, I have to figure it all out again.

Created directory /etc/webalizer.d/ with an entry for each website, e.g. /etc/webalizer.d/fred for fred.com, containing a copy of the /etc/webalizer.conf sample file, with the name of the log file changed and the output going into /var/www/usage/fred

Created backup_scripts/webalizer containing:

for W in /etc/webalizer.d/*.conf; do /usr/bin/webalizer -c $W; done

Started the script from crontab.

In apache, I have a 443 virtualhost for usage.wmbuck.net which gives me the statistics for website fred when invoked with https://usage.wmbuck.net/fred.

boot issues, fedora, linux, ubuntu

Useful kernel parameters

This is just a memory aid.

Most kernel parameters are documented at www.kernel.org

Kernel parameters: doc/html/latest/admin-guide/kernel-parameters.txt

  • boot_delay=n    delay n milliseconds between printk. n<10000
  • console=ttyS1 =ttyUSB0
  • debug                     enable kernel debugging
  • module.dnydbg     see Documentation/dynamic-debug-howto.txt
  • enforcing=0/1  initial SELinux enforcing status
  • ignore_loglevel  ALL printk to the console
  • loglevel=0-7  All printk <n will be printed to console
  • module_blacklist=  comma separated
  • S single mode
  • selinux=0/1 disable selinux
  • apparmor=0/1 disable apparmor

Continue reading Useful kernel parameters →

boot issues, fedora, linux, ubuntu

Not starting X Windows

I had some trouble with the graphics drivers, and needed to start the system in runlevel 3. How to do that? Can’t just use the old inittab configuration file and set initdefault to 3 anymore.

I ended up changing the systemd default target. On the running system the /etc/systemd/system/default.target is a symlink to /usr/lib/systemd/system/graphical.target, but if I replace that with a symlink to /usr/lib/systemd/system/multi-user.target, that system will come up to runlevel 3. The easy way to do this is in systemctl

systemctl set-default multi-user-target
systemctl set-default graphical-target

I didn’t do it, but I also found a post recently that said you can simply put a runlevel on the end of the grub command line, i.e. add 3

eclipse, fedora, linux, ubuntu

GTK Tooltips and Eclipse

Eclipse on Fedora (and as I read it, also on Ubuntu) has now got a problem with colors. Specifically, when one hovers over a function to obtain the calling sequence, a pop up appears to provide this information but the background of the pop-up is black, which makes the content unreadable. This is relatively new, though I’m not sure whether it was with the change to Eclipse Neon or earlier, or the change to Fedora 24.

It turns out this is not a setting in eclipse, although I wasted quite a lot of time looking for it. This ends up being a system setting, associated with gtk, the graphical toolkit. If one starts eclipse with

export SWT_GTK3=0;eclipse

which starts eclipse with gtk 2.0, instead of gtk 3.0, the problem goes away, the background of the pop-ups becomes a nice cream color.

The settings we are using are set in the theme one chooses, the default theme being Adwaita. The themes are kept in /usr/share/themes. I tried simply changing to a different theme (TraditionalOk) but the setting affecting this did not change. So I resorted to force.

In /usr/share/themes/TraditionalOk there are directories for gtk-2.0 and gtk-3.0. Within gtk-3.0 I changed the file gtk-widgets.css, specifically, I changed the setting in the tooltip section to background-color #f5f5b5; Previously the value was “@theme_tooltip_bg_color;” and as I read it, that define ought to have the value #f5f5b5. But something is wrong, and the setting is disruptd. But forcing it this way, it seems to work.

apache, javascript, linux, ubuntu, website building

Ubuntu Javascript Fail

The “out of the box” apache on Ubuntu comes with a “feature” called “javascript-common” enabled. I haven’t got much idea what this wretched thing does, other than screw me up. I remember now that I had to struggle this some time back on Cinnamon. Now I am in Ohio trying to get something running on a box there, and tearing my hair out once again over the same issue.

This feature adds an Alias directive that takes the directory “/javascript” and sends it off to /usr/share/javascript. So if you are foolish enough to have a directory in your website called “/javascript” (and who would ever dream of putting their javascript files in a directory called javascript, after all) it will fail.

The directory /usr/share/javascript has some nice stuff in it, including jquery, and I guess it is a nice convenience feature for some people. But am I the only one who things it is crazy for a distribution to do something that breaks websites that have a commonly named directory like javascript!?

fedora, kodi, linux, mac, ubuntu, xbmc

Correcting Corrupted Kodi Database

I’ve had several cases where one of the Kodi sqlite3 databases becomes corrupted on Coriander. It has happened to Textures, Addons and EPG at different times.  The error that manifests in the Kodi log is The Database Disk Image is Malformed, and once it happens the log is full of this and transactions in the affected database don’t take place.

Did some reading, and discovered that usually you can dump the database, and the dump will be ok.  Try this:

echo '.dump' | sqlite3 fred | sqlite3 new_fred
mv fred bad_fred
mv new_fred fred
fedora, linux, mail, postfix

Webmail

Update 2017-08-07:

I switched from using squirrelmail to a product called rainloop. Rainloop was relatively easy to install, and is far nicer that squirrelmail. But the basic idea is the same.

A next step for providing mail service for some of my users is a primitive webmail facility. For this I used a product called squirrelmail.

Squirrelmail installs, on fedora, into /usr/share/squirrelmail, with config in /etc/squirrelmail. /usr/share/squirrelmail/config contains a perl script, conf.pl, which provides a simpler configuration experience with explanation of all the somewhat cryptically named fields.

As part of doing this I obtained certificates for all the domains I am hosting – at least all of them over which I have enough control to meet the validation requirements of startssl.com, meaning either I am postmaster or the documentroot of the website is on tarragon. Without this I would have to choose between not encrypting the mail, or having the user have to put up with mail programs complaining about the certificate.

asterisk, fedora, kodi, linux, mac, ubuntu, xbmc

Caller Id in Kodi – Redux

I posted in this post about how I arranged to get caller-Id to show up in Kodi. At that time I was still using POTS, but since then I have switched to VoIP and set up Asterisk.

I did find another plugin that would connect to Asterisk and obtain information about incoming calls. But until now it was only half way working. I finally got around to paying attention to it. It was originally provided by “hmronline” and I found it at code.google.com. It was last worked on with Dharma, and I had to do some things to get it ready for Jarvis.

The source code is now in the tarragon svn repository, under the name KodiAsterisk. On coriander, where the production Kodi lives, there is a checked out directory under /Users/wmb called kodiasterisk. For Kodi to install it it has to be zipped, so the sequence is to svn update the directory, then zip the directory as script.service.dee-kodi-asterisk.zip. Then install it within Kodi.

It attaches to asterisk on cinnamon using the Asterisk manager interface.  Authentication on the manager interface uses files in /etc/asterisk/manager.d which has one file per authorized user, containing credentials.

The code has features to

  • give a notification of the caller id
  • put up a picture of the caller
  • pause a video if one is playing
  • redirect the call (within asterisk) if a video is playing
  • indicate whether there are voice mails

I have the notification running, the picture coming up, and the video being paused. I don’t use the redirect feature. Also, since my voice mail is not on Asterisk the features of voice mail aren’t being used.

I did put pictures into a folder within /Storage/Pictures/KodiPictures. The pictures here are named with the phone number, and contain a snapshot of the caller, in jpeg. If there is no picture in the folder for a particular number nothing is put up, but the notification and pausing still occur.