my past 2 articles for LinuxInside

Following my first article on the Greek Linux Magazine called LinuxInside about IPv6, I uploaded my past 2 articles for it. Both articles are in Greek of course.

The first one is about debugging network connectivity issues using the command line on Linux. It was published on the 2nd issue of LinuxInside.
Εντοπίζοντας ένα πρόβλημα δικτύωσης

The other one is an introduction to Zsh. It was published on the 3rd issue of LinuxInside.
Κατακτήστε το Z shell

If you haven’t read the magazine already, feel free to download those pdfs and read them.
All my presentations/articles can be found at: Articles/Presentations

AAAA records with Plesk

Plesk is surely not ready for IPv6. Despite that fact, many people – me included, have the DNS records of their favorite domains managed by Plesk and still want to be able to add some IPv6 records to those.

Some time ago I had posted on my twitter account a link to another blog that had a “hackish way” to add AAAA records to Plesk. I have written a slightly more elegant shell script (to be run by root only) than the one provided by experimentalworks.

First of all you _need_ to alter dns_recs table of the psa database to allow AAAA records:

# mysql -u admin -p psa 
mysql> alter table dns_recs modify column type enum('NS','A','AAAA','CNAME','MX','PTR','TXT','SRV','master','none') NOT NULL default 'A'; 

Then download my plesk-AAAA.sh script and use it like the following example.

To add www.foobar.gr to point to 2001:db8:1001::1

Usage: ./plesk-AAAA.sh [zone serial]
#./plesk-AAAA.sh foobar.gr www 2001:db8:1001::1
#./plesk-AAAA.sh foobar.gr ipv6 2001:db8:1001::1 12

Known bug/feature:
If you add a record without adding a serial, for the soa record, at the end, it will add the serial of the domain in the form:

YYYYMMDD10

So if you add two ipv6 hosts in the same day for the same domain you _have_ to manually add a serial >10 for the second host (and so forth).

For the ones who don’t like downloading but would like to see the script source, here it is:

  1 #!/bin/sh
  2 
  3 usage () {
  4         echo "Usage: $0 <domain> <hostname> <v6 IP> [zone serial]"
  5         echo "Usage: $0 foobar.gr www 2001:db8:1001::1"
  6         exit 1
  7 }
  8 
  9 if [ $# -lt 3 ]; then
 10         usage
 11 fi
 12 DOMAIN=$1
 13 HOSTNAME=$2
 14 v6IP=$3
 15 INPUT_SERIAL=${4:-10}
 16 FULLHOST="$2.$1."
 17 
 18 ADMIN_PASS=`cat /etc/psa/.psa.shadow`
 19 MYSQL_BIN_D=`grep MYSQL_BIN_D /etc/psa/psa.conf | awk '{print $2}'`
 20 PRODUCT_ROOT_D=`grep PRODUCT_ROOT_D /etc/psa/psa.conf | awk '{print $2}'`
 21 SERIAL=`date +%Y%m%d${INPUT_SERIAL}`
 22 mysql="${MYSQL_BIN_D}/mysql -N -uadmin -p${ADMIN_PASS} psa"
 23 
 24 query1="SELECT dns_zone_id FROM dns_recs where host like \"$DOMAIN%\" LIMIT 0,1"
 25 ZONE_ID=`echo "$query1" | $mysql`
 26 echo "ZONE_ID=$ZONE_ID"
 27 query2="INSERT INTO dns_recs (displayHost, host, displayVal, val, type, dns_zone_id) VALUES ('$FULLHOST', '$FULLHOST', '$v6IP', '$v6IP', 'AAAA',$ZONE_ID)"
 28 echo "$query2" | $mysql
 29 
 30 query3="UPDATE dns_zone SET serial=\"$SERIAL\" WHERE id=$ZONE_ID LIMIT 1;"
 31 echo "$query3" | $mysql
 32 
 33 echo "REBUILDING zone file for $DOMAIN"
 34 $PRODUCT_ROOT_D/admin/sbin/dnsmng update $DOMAIN

The script has been tested with bash and zsh. I have no idea whether it works under any other shells.
The script probably won’t delete your databases, but…use it at your own risk :) I hope someone finds it useful.

command exit status on zsh using RPROMPT

I’ve just updated by .zshrc so that I can get the exit status of commands on a “right prompt” using zsh’s RPROMPT variable. Exit status appears only if the value is non-zero.

Example usage:
zsh-rpropmpt-exit-codes

You can find my zshrc and more dot files that I use in my Pages/My dot files