e-සටහන්: April 2014

Followed the guidance from http://www.wandisco.com/svnforum/threads/38244-How-to-move-svn-repository-from-one-server-to-another and support from http://fedoraproject.org/wiki/How_to_edit_iptables_rules and http://holtstrom.com/michael/blog/post/400/Port-Forwarding-Gateway-via-iptables-on-Linux.html

Dump old repositories to files.
I used the shell script below, a customization of the script found in http://www.hossainkhan.info/content/shell-script-backup-all-your-svn-repositories
svn-dump.sh

#!/bin/sh
################################################
#
# Backup SVN repos to local folder
#
# @author   Hossain Khan
# @email    contact [at] hossainkhan [dot] info
# @version  v0.01
# @reldate  2010-03-27
################################################
#  Copyright (c) 2010 Hossain Khan
# 
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:
# 
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.
# ----------------------- END OF LICENSE TEXT ----------------------
 
# Record todays date
# --------------------
bakdate=$(date +%Y%m%d%H%M)
echo "--------------------------------"
echo "Running SVN backup $bakdate"
echo "--------------------------------\n"
 
# From where to backup repos?
# ---------------------------
svnrepos="/mnt/datadisk/svnrepo"
echo "\nGoing to backup all SVN repos located at: $svnrepos \n"
 
# Where to save the dump?
# ------------------------
bakdest="/home/sdu/svn-backups-20140331"
 
# Location for USB drive? (to copy backup)
# ----------------------------------------
baktousb="/media/USB/Extra-BACKUP"
 
# _________NO-COFIG-REQUIRED-BELOW-THIS-LINE___________
 
# First go to SVN repo folder
cd $svnrepos
 
 
# Just make sure we have write access to backup-folder
if [ -d "$bakdest" ] && [ -w "$bakdest" ] ; then
  # Now $repo has folder names = project names
  for repo in *; do
    # do svn dump for each project
    echo "Taking backup/svndump for: $repo"
    echo "Executing : svnadmin dump $repo > $bakdest/$repo-$bakdate.svn.dump \n"
    # Now finally execute the backup
    svnadmin dump $repo > $bakdest/$repo-$bakdate.svn.dump
    # You can go an extra mile by applying tar-gz compression to svn-dumps
 
    # We also would like to save the dump to remote place/usb
    if [ -d "$baktousb" ] && [ -w "$baktousb" ] ; then
      # USB/other directory exists, copy the dump there
      echo "Going to copy $repo dump to $baktousb directory...\n"
      cp $bakdest/$repo-$bakdate.svn.dump $baktousb
    fi 
  done
else
  echo "Unable to continue SVN backup process."
  echo "$bakdest is *NOT* a directory or you do not have write permission."
fi
 
 
# End of backup script
echo "\n\n================================="
echo " - Backup Complete, THANK YOU :-]"

Install, configure and start subversion in the new server.
help: https://injustfiveminutes.com/2013/01/24/how-to-install-subversion-on-centos-6-x/

```
yum install subversion
```
```
/usr/sbin/useradd svn
```
```
passwd svn
```
```
cd /var
```
```
mkdir repos_svn
```
This is where our repositories will reside

chown -R apache:svn repos_svn/
You can use cat /etc/passwd | cut -d: -f1 and cat /etc/group |cut -d: -f1 list users & groups

```
chmod -R 774 repos_svn/
```
```
chmod -R 774 /var/repos_svn/
```
```
chmod g+s /var/repos_svn/
```
Configure the svnserve.conf file. This file can be obtained by creating a test repository.
```
svnadmin create /var/repos_svn/test
```

cp /var/repos_svn/test/conf/svnserve.conf .

Made the folowign modifications to the svnserve.conf file.
```
auth-access = write
anon-access = none
realm = SDU
```
I did not enable the "password-db = passwd" line because I'm going to use sasl2 passwords file instead of the default plain text password file. I will create the sasl2 password file first for testing and later replace it with the file from my old server (in order to migrate existing users).

saslpasswd2 -f /var/repos_svn/sasl2db -u SDU testusername

svnserve -d --root=/var/repos_svn/ --config-file=/var/repos_svn/svnserve.conf

Start the subversion daemon with the global configuration file.

```
netstat -tulpn
```
Check whether the daemon is listening on port 3690

Since iptables is "on" by default on CentOS and rejects any traffic on ports except 22, I had to add rules to allow svn port before testing.

/etc/init.d/iptables start
chkconfig iptables on

iptables --line-numbers -n -L
# HTTP
iptables -I INPUT 5 -p tcp --dport 80 -j ACCEPT
# SVN
iptables -I INPUT 6 -p tcp --dport 3690 -j ACCEPT

/etc/init.d/iptables save

help: http://www.cyberciti.biz/faq/turn-on-turn-off-firewall-in-linux/

The test repository created was available at svn://192.248.10.122/test

Restore repository dumps.
svn-restore.sh

#!/bin/sh
 
# From where to load repos?
# ---------------------------
svnrepos="/var/repos_svn"
echo "\nGoing to restore all SVN repos to: $svnrepos \n"
 
# Where to load the dump from?
# ------------------------
bakdest="/root/svn-backups"
 
# _________NO-COFIG-REQUIRED-BELOW-THIS-LINE___________
 
# First go to SVN repo dumps folder
cd $bakdest 
 
# Just make sure we have write access to backup-folder
if [ -d "$svnrepos" ] && [ -w "$svnrepos" ] ; then
  # Now $repo has folder names = project names
  for repo in *; do
 # do svn dump for each project
 echo "Restoring backup/svndump of: $repo"
 echo "Executing : svnadmin create $svnrepos/$repo \n"
 svnadmin create $svnrepos/$repo
 echo "Executing : svnadmin load $svnrepos/$repo < $repo \n"
 svnadmin load $svnrepos/$repo < $repo
  done
else
  echo "Unable to continue SVN restoration."
  echo "$svnrepos is *NOT* a directory or you do not have write permission."
fi
 
 
# End of backup script
echo "\n\n================================="
echo " - Restoration Complete, THANK YOU :-]"

Copy the sasl2db password file from old server to the new server
Relocate working copies to point to the new server

Notes

If your subersion client gives the error "Could not obtain the list of SASL mechanisms" try installing the cyrus-sasl-md5 package and restarting the subversion daemon.

If you get the error "SASL(-1): generic failure: unable to find a callback: 2" make sure that the /etc/sasl2/svn.conf file looks like below

/etc/sasl2/svn.conf

pwcheck_method: auxprop
auxprop_plugin: sasldb
sasldb_path: /var/repos_svn/sasl2db
mech_list: DIGEST-MD5

in detail: http://www.question-defense.com/2009/06/16/could-not-obtain-the-list-of-sasl-mechanisms

Additional Resources

A shell script for easily starting and stopping subversion daemon.
svnserve.sh

#!/bin/sh
REPO_ROOT=/var/repos_svn
#SVN_UID=subversion
#SVN_GID=subversion
#. /etc/rc.status
#rc_reset
case "$1" in
   start)
        echo -n "Starting svnserve ... "
        #startproc -u $SVN_UID -g $SVN_GID -e svnserve -d -R -r $REPO_ROOT
        svnserve -d --root=$REPO_ROOT/ --config-file=$REPO_ROOT/svnserve.conf
        echo "[OK]"
        #rc_status -v
        ;;
   stop)
        echo -n "Shutting down svnserve ... "
        #killproc -TERM svnserve
        killall svnserve
        #rc_status -v
        ;;
   restart)
        $0 stop
        $0 start
        #rc_status
        ;;
   *)
        echo "Usage: $0 {start|stop|restart}"
        exit 1
        ;;
esac
#rc_exit
exit 0

A shell script for easily creating new project repositories.
svn-new.sh

#!/bin/bash

if [ "$#" != 1 ]; then
        echo "You need exactly one parameter ."
else
        if [ -d /var/repos_svn/$1 ]; then
                 echo "[Error]: Repository \"$1\" already exists."
        else
                cd /var/repos_svn

                echo "Initializing the project in the repository ..."
                svnadmin create /var/repos_svn/$1
                chown -R www-data:svn repos_svn/
                chmod -R 774 repos_svn/
                echo "Done."

                echo "Please use the convention of directories \\trunk \\tags \\branches for storing your project"
  #echo "You may need to start the svn-server using the command \"/etc/init.d/svnserve start\""
                echo "Please note that you have to Check-Out the project from the repository before working."
                echo "Your repository URL is: svn://192.248.10.122/$1"
                #echo "Don't forget to create the users with: htpasswd /etc/apache2/dav_svn.passwd "
                echo "Don't forget to create users with: \"saslpasswd2 -f /var/repos_svn/sasl2db -u SDU \" command"
        fi
fi

NAT rules for public IP access
I also defined NAT rule to the new server from my primary server to allow it access via a public IP address.

Made the folowign modification to the /etc/sysctl.conf file.

/etc/sysctl.conf


net.ipv4.ip_forward = 1

Issued following commands to configure the NAT forwarding.

sysctl -p /etc/sysctl.conf
iptables -I FORWARD -i eth1 -p tcp -d 192.168.22.143 --dport 3690 -j ACCEPT
# delete the reject rule to allow opening of random port to forward request
iptables -D FORWARD 2
# add NAT rules
iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 3690 -j DNAT --to-destination 192.168.22.143:3690
iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE
# check whether successful
/etc/init.d/iptables status
# save
/etc/init.d/iptables save

Enable listing of repositories via HTTP

yum install mod_dav_svn

# edit /etc/httpd/conf.d/subversion.conf
<Location /svn>
  DAV svn
  SVNParentPath /var/repos_svn
  SVNListParentPath On
  <LimitExcept GET PROPFIND OPTIONS REPORT>
     Require valid-user
  </LimitExcept>
</Location>
<Location ~ "/svn/.+">
   Require valid-user
</Location>

# restart httpd
service httpd restart

e-සටහන්

Friday, April 4, 2014

MS SQL Server 2000 Row Numbering

Tuesday, April 1, 2014

Moving old Subversion repositories to a new server