The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘openSuSE’ Category

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domain name system – How to test DNS glue record? – Server Fault

Posted by jpluimers on 2016/05/26

Thanks Adrian W for providing the below example in your answer about obtaining GLUE record information for a domain.

It is an excellent showcase for the $IFS Internal Field Separator available in any nx shell.

In this case it is used to get the TLD (top-level domain) from the domain name specified at the command-line.

After that, it obtains the name servers for that TLD, and queries the glue records there, both using dig.

Here is a little shell script which implements Alnitak’s answer:

#!/bin/sh
S=${IFS}
IFS=.
for P in $1; do
  TLD=${P}
done
IFS=${S}

echo "TLD: ${TLD}"
DNSLIST=$(dig +short ${TLD}. NS)
for DNS in ${DNSLIST}; do
  echo "Checking ${DNS}"
  dig +norec +nocomments +noquestion +nostats +nocmd @${DNS} $1 NS
done

Pass the name of the domain as parameter:

./checkgluerecords.sh example.org

–jeroen

via domain name system – How to test DNS glue record? – Server Fault.

Posted in *nix, Apple, bash, Development, DNS, Linux, Mac, Mac OS X / OS X / MacOS, Mac OS X 10.4 Tiger, Mac OS X 10.5 Leopard, Mac OS X 10.6 Snow Leopard, Mac OS X 10.7 Lion, openSuSE, OS X 10.10 Yosemite, OS X 10.8 Mountain Lion, OS X 10.9 Mavericks, Power User, Scripting, Software Development, SuSE Linux | Leave a Comment »

Nice diskinfo alias showing du, df, btrfs, parted, lsblk

Posted by jpluimers on 2016/05/20

I bumped into a disk full issue again because of the btrfs/snapper combination in openSuSE and df basically lying about the disk space, so I w rote this Nice diskinfo alias showing du, df, btrfs, parted, lsblk.

You can combine this with A bash script to btrfs snapshot details like disk sizes (requires btrfs quota to be enabled) to find out which snapper snapshots take up a truckload of space and might be safely removed.

–jeroen

via: How can a partition be full if du does not show it is? (via: linux – Super User) #OpenSuSE #btrfs #snapshots « The Wiert Corner – irregular stream of stuff.

Posted in *nix, *nix-tools, Linux, openSuSE, Power User, SuSE Linux | Leave a Comment »

Latest Tumbleweed distribution update likely kills sshd

Posted by jpluimers on 2016/05/03

After a recent big update to OpenSuSE Tumbleweed, I could not ssh into my system any more.

Symptoms

The ssh client side would report a Read from socket failed: Connection reset by peer which I misinterpreted as the sshd not running at all.

Luckily the server is a VM, so I could reach the console. There I saw this:

sshd trying to load files it shouldn't

sshd trying to load files it shouldn’t

The files should not be loaded as they are not specified in the sshd_config file:

dsa and ecdsa not specified in the config file

dsa and ecdsa not specified in the config file

So I knew something was broken. After reading some messages in the forums.opensuse.org I got at Bug 977812 – sshd killed by SIGSYS on client connection

The cause

As usual with such issues the cause seems a combination of factors:

And we have the culprit, I believe: together with the glibc upgrade, openssl
was updated from 1.0.2g-1.1 to 1.0.2-2.12 which brought, among others, patch
openssl-urandom-reseeding.patch.

Temporary fix

A temporary fix is to comment out a line in /etc/sshd_config so you get this diff:

-UsePrivilegeSeparation sandbox # Default for new installations.
+# UsePrivilegeSeparation sandbox # Default for new installations.

Be sure to undo this as soon as you’ve received a final fix.

Final fix

A final fix is being fast-tracked so it appears in Tumbleweed soon.

I will report after deployment of [opensuse-factory] New Tumbleweed snapshot 20160502 released! as I think it contains the fix.

Aftermath

I already knew about openQA: Test summary which lists the builds, but not the changes in the builds.

Reading through Information Board or the like for Tumbleweed I found the openSUSE Mailinglist Archive: opensuse-factory which does the announcements and release notes for Tumbleweed.

It had both the announcement of the “big patch”, ssh bug report and temporary fix:

–jeroen

 

 

Posted in *nix, Communications Development, Development, Internet protocol suite, Linux, openSuSE, Power User, SSH, SuSE Linux, TCP, Tumbleweed | 2 Comments »

DVCS for your Linux etc configuration

Posted by jpluimers on 2016/04/11

Manually you can do it like this: How To Use Git to Manage your User Configuration Files on a Linux VPS | DigitalOcean.

But there is also etckeeper. There is even a set of manual installation steps for opensuse: backup – etckeeper for opensuse – bash script install and configure – Unix & Linux Stack Exchange.

Three important etckeeper gotchas with powerful scripts like pre-commit /etc/etckeeper/pre-commit.d:

  • Ensure you give them executable permissions like chmod 755.
  • Ensure they are valid sh scripts.
  • Do not give them the .sh extension:
    • fails: /etc/etckeeper/pre-commit.d/10rsync-var-lib-named-master
    • works: /etc/etckeeper/pre-commit.d/10rsync-var-lib-named-master.sh

–jeroen

via:

Posted in *nix, *nix-tools, etckeeper, Linux, openSuSE, Power User, SuSE Linux | Leave a Comment »

Upgrading from OpenSuSE 13.1 to 13.2

Posted by jpluimers on 2016/03/14

As etckeeper wasn’t available in the “normal” OpeenSuSE 13.1 package, I used the steps below to upgrade to 13.2 after reading SDB:System upgrade – openSUSE and How To Upgrade To openSUSE 13.2 From openSUSE 13.1 | Unixmen.

Note I installed inside tmux (to prevent any ssh disconnects from screwing the upgrade process):

Read the rest of this entry »

Posted in *nix, etckeeper, Linux, openSuSE, Power User, SuSE Linux | Leave a Comment »

Mosh: the mobile shell

Posted by jpluimers on 2016/03/07

Reminder: install mosh and get it working when it runs behind a firewall.

Mobile shell that supports roaming and intelligent local echo. Like SSH secure shell, but allows mobility and more responsive and robust.

Links:

Then see how well it stacks up against or complements with the ssh/tmux combo.

–jeroen

Read the rest of this entry »

Posted in *nix, Linux, openSuSE, Power User, SuSE Linux, Tumbleweed | Leave a Comment »

/etc/netconfig conflict

Posted by jpluimers on 2015/12/13

Hmm:

Detected 1 file conflict:

File /etc/netconfig
  from install of
     libtirpc3-1.0.1-1.1.x86_64 (Main Repository (OSS))
  conflicts with file from install of
     libtirpc1-0.2.5-1.1.x86_64 (openSUSE-20150508-0)

File conflicts happen when two packages attempt to install files with the same name but different contents. If you continue, conflicting files will be replaced losing the previous content.

Changes: go figure (:

revue:/etc # diff netconfig.201507191158 netconfig
13,14d12
< udp6       tpi_clts      v     inet6    udp     -       -
 udp6       tpi_clts      v     inet6    udp     -       -
> tcp6       tpi_cots_ord  v     inet6    tcp     -       -

–jeroen

Posted in *nix, Linux, openSuSE, Power User, SuSE Linux | Leave a Comment »

Recommended read: What I learned while securing Ubuntu – major.io

Posted by jpluimers on 2015/11/24

Applying security hardening standards and generally securing Ubuntu has been a challenge.

Tell me about it (:

–jeroen

Source: What I learned while securing Ubuntu – major.io

Posted in *nix, *nix-tools, Linux, openSuSE, Power User, SuSE Linux | Leave a Comment »

Reminder to self: verify which temporary directories really need cleanup through systemd’s tmpfile mechanism

Posted by jpluimers on 2015/11/20

Message from package aaa_base:

sysconfig settings for cleaning up temporary directories are no longer
supported. Some of the features are provided by systemd's tmpfile
mechanism instead. Please refer to 'man tmpfiles.d' for more
information.

Here are the old settings for reference:

MAX_DAYS_IN_TMP=0
MAX_DAYS_IN_LONG_TMP=0
OWNER_TO_KEEP_IN_TMP=root

–jeroen

Posted in *nix, Linux, openSuSE, Power User, SuSE Linux | Leave a Comment »

The Power of Open Source… Microsoft .NET and OpenShift: .Net on Linux

Posted by jpluimers on 2015/11/11

Really exiting times ahead: Microsoft .Net on Linux.

It’s not fully ready yet, but to get an idea to learn more about running OpenShift Enterprise 3 and a .NET application based on a Red Hat Enterprise Linux container, here are a few links to get started:

I wish that the demo repository at https://github.com/munchee13/snoopalicious.git and the rhosepaas.com domain were accessible (:

There are other alternatives too, but OpenShift (RedHat) and Microsoft working together is really exiting news to me.

If you’re on other distros, here are some more links:

And of course there has been Mono for a while, which is a different implementation of .NET:

Hopefully this will have search results soon: dnvm opensuse tumbleweed.

–jeroen

Posted in *nix, .NET, Development, Linux, OpenShift, openSuSE, Power User, RedHat, Software Development, SuSE Linux, Tumbleweed | Leave a Comment »

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