Today i describe the few steps of installation of subversion (with repository) on Linux (Debian lenny). That description show the installtion proccess in 5 steps. And the configuration of Apache Mod-DAV as additiona information. So let’s start.
If subversion is not installed, install it with:
$apt-get install subversion
Today i’ll give you some interesting examples of using lsof command.
lsof stands for “list open files”. So actually it shows all files used by some processes of a system. That command exist on most of and on different Linuxes and Unixes.
It bases on architecture of a kernel which causes evety procces to hold it used files in /proc – (a virtual file-system). A typical hierarchy wold look like:
/proc/process id/fd/file descriptor
In the absence of any options, lsof lists all open files belonging to all active processes of a system. But that is to much for most cases, because many of cases are networkrelated. An if you consider that sockets are files in linux we can use lsof to search fo them. Read more »
I noticed that my last post was a 101 post on this blog which is good occasion to do some self evaluation.
I started to write here in January 2007 it’s nearly 4 years ago. You see I’m not very productive blogger. Nevertheless i wrote some interesting things which have attracted some people or comments. Here some of them chronologically:
I’ve learned pretty much and i tried different themes. I think in the future i will write more and more technical stuff. So e.g. Java comes to short so far also web technologies where not covered while i have to do with them relatively often. Read more »
Yesterday i installed Ubuntu (10) linux alongside of Windows XP (SP3) on my Lenovo Thinkpad T60 – meanwhile 4 years Laptop. To be short i observe only start-time of both system on the same machine in this post.
Here some hardware details:
An here are starttimes on two Systems (in seconds):
As we see Windows takes 1 minute from OS-Selection dialog till User-login dialog, whereas Ubunto takes only 24 sec. Ok, windows checks “security chip” (what it exactly means and why it so good for me i don’t know) and that takes considerable time and i’m unsure whether Ubunto do something like this, but however i can’t change it.
On a graph we see also, that for the rest of “loading work” from login till first page appears in firefox browser windows takes more time again. It takes 95 seconds whereas Ubunto need only 19! I was clicking on browser Icon as soon it appeared and was “clickable” and waited till pre-selected starting page (google) appears.
Of cause tas is not very strict measurement so maybe I’ve lost one or two seconds somewhere, who cares if
till i can use my typical day by day application. So now i can save more than a one and halfe minute of my life on every start of a system.
Respect Ubuntu, keep on going!
Here give a short overview of important JSR of Java Community Process which define and standardises WebServices development on Java Platform.
Did I forgot something?
Probably most of modern IT related people know Atlassian JIRA – issue and project tracking system. Maybe many of you know other popular tracking system like Bugzilla, GNATS, und many many others. Personally I like JIRA last but not least because i worked many years with it and I’m impressed of a simplicity of the work flow and the realisation of the concepts around it.
However this is not one post which should bring JIRA near to you. But if you know that you need it, now is best time to get it, because Atlassian started their “Get Startet” Price, which now allows you to by full functional JIRA for 10$ for ever even with one year support. All you need is a little bit of free CPU time, root access, 10$ and if you buy it outside of USA, you will need a credit card.
I installed it for my private purposes and it works fine! I just followed Atlassian documentation (Read it carefully). Maybe, the easiest way is to install the “all in one” solution which comes with Apache Tomcat. I choosed that one. But don’t forget to switch to serious database before you start really using it. Take MySQL for example like I did.
I will not provide here step by step how to do it, because Simon has already described some of the important configurations moments as he heard about new pricing 
and as already mentioned the Atlassian installation guide is good and really answered all my questions.
Nevertheless feel free to ask questions here, about installation and configuration to.
Also i would like to discuss other Atlassian developer tools which also available for 10$. Is here outside someone experienced in bamboo?
Queen Elizabeth II head of the Commonwealth and daugher of George VI. She was born on 21 April 1926 and have seen lot of politics and historical acts in her life, because now she is 84!
As her father dies in 1952, she become the Queen regnant an met 11 Presidents of United States till now:
Today I’ll describe short, how to configure sending of emails with your Debian or other Linux distribution. The ability of sending mails is very useful feature for every long-running server machine, it’s easy and common way to notify the administrator on problems.
Here are configurationsteps for mail-sending with Exim and Googlemail account (google Apps accounts work the same way too).
$ apt-get update $ apt-get install exim4
$ dpkg-reconfigure exim4-config
Other parameter are not so important for a start. However read more about debconf questions and other configuration if you like.
gmail-smtp.l.google.com:yourYourMail@googlemail.com:yourPass *.google.com:yourYourMail@googlemail.com:yourPass smtp.gmail.com:yourYourMail@googlemail.com:yourPass
$ chown root:Debian-exim /etc/exim4/passwd.client
$ update-exim4.conf
Your ‘re done!
Now it’s test it with.
echo "Server Mail Test Message " | mail -s "Just Test" SomeMail@someDomain.org
Watch logs:
$ tail -1000f /var/log/exim4/mainlog
When you see something like this. Everything should vent perfect.
2010-02-14 23:00:26 1NgmVu-0007v8-Kt < = root@mail-server1.mycompany.com U=root P=local S=424 2010-02-14 23:00:28 1NgmVu-0007v8-Kt => testMail@mycompany.org R=smarthost T=remote_smtp_smarthost H=gmail-smtp-msa.l.google.com [72.14.221.109] X=TLS1.0:RSA_ARCFOUR_MD5:16 DN="C=US,ST=California,L=Mountain View,O=Google Inc,CN=smtp.gmail.com"
What should young people do at a long, cold, rich of snow and boring winter. A winter like in Magadan town.
Here the answer
Never heard of Magadan?
Magadan is associated with far far east of Russia. It is associated with cold and people-less places, taiga, beautiful nature and interesting people. Of course this Region is famous for former Soviet GULAGs too.
SSH (Secure Shell) allows simple establishment of encrypted and authenticated connection between computers. Today i describe how easy it is do establish such SSH tunnels without using a password. You may need such connections when they have to be opened by daemons (e.g. Cron) without user interaction.
Two words on theory. Password-less connections have to be authenticated at least so strong like the password enabled one, so asymmetric cryptography which enables certificates comes into play. The clue is to have private and public keys and share your public key with domains which should be able identify you.
So therefore let’s start by generation a needed key-pair.
It is possible to create key with pass-phrase and without (or empty pass-phrases). I prefer to not use pass phrase because it is asked every-time on later usage of a ssh.
Even there are ways to gives the pass-phrase to ssh command, but it is more work, with no significant security benefits. So i do the following statement and do not enter any pass-phrase (just hit enter on question).
$ ssh-keygen -t rsa
This will create RSA key-pair as following files in ~/.ssh directory:
Now public key need to be copied to remote host and has to be added to end of ~/.ssh/authorized_keys file.
The best way to do it is to use ssh-copy-id program which is inside of many linux distributions.
$ ssh-copy-id -i ~/.ssh/id_rsa.pub remote-user@remote-server.org
In that case everything is done automatically and you are ready after that. But if ssh-copy-id is not available, you can copy keys manually e.g. like that.
$ cat ~/.ssh/*.pub | ssh remote-user@remote-server.org 'umask 077; cat >>.ssh/authorized_keys'
Attention! On some linux distrs SSH2 searches for keys in ~/.ssh/authorized_keys2 . Not so in actual Debian (Lenny), but seems to be so in SuSe linux.
Now remote login, scp and sftp can be used without password.
Test it:
# establish connection $ ssh remote-user@remote-server.org #or copy files secure and password-less. $ scp /home/user/some-file remote-user@remote-server.org:/some-path/dir/
More information on SSH related man pages.
This short tutorial describes how to configure JBoss Application Server (Jboss GA 5.1.0) on a debian linux (Debian GNU/Linux 5.x “Lenny” ). Article starts with installation of java JDK and continues with JBoss installation and basic configuration according to standard file system hierarchy. Also init.d. scripts configuration is given here.
Nowadays installing Java environment on Debian is an easy task. I used JDK 1.6. Don’t confound JDK with JRE, because bare Java Runtime Environment is not enough for running JBoss. Debian Wiki maintains (hope) a list of available java .deb packages, which are easily can be installed with your preferred way. I prefer aptitude, but apt-get of course works too.
$ aptitude install sun-java6-jdk #or by good old apt-get. $ apt-get install sun-java6-jdk
Installation is done after seconds. Now test your java installation with
$ java -version # Here example result on my configuration: java version "1.6.0_12" Java(TM) SE Runtime Environment (build 1.6.0_12-b04) Java HotSpot(TM) 64-Bit Server VM (build 11.2-b01, mixed mode)
If you get something like this, you’re done and your java should be already in the PATH.
Now let’s install JBoss Application Server.
Normally you are not willing to start services (especially when they are accessed from outher machines) with root privileges. Therefore we have to define new user and group which will be used to manage JBoss. So next line will create new group and new user with this group.
$ groupadd jboss $ useradd -s /bin/bash -d /home/jboss -m -g jboss jboss
This jboss user has no password, so nobody can login with this username. If you consider to login with jboss user, password has to be set. Use passwd jboss command for that.
Now download desired Jboss version. I started with JBoss 5.1.0 GA, which can be download with:
$ cd /tmp # swithch to temp dir $ wget http://sourceforge.net/projects/jboss/files/JBoss/JBoss-5.1.0.GA/jboss-5.1.0.GA.zip/download
Check also the whole list of verisons if interested. As you may noticed JBoss binaries are packaged with ZIP. So it is comfortable to use unzip tool. Maybe you have to install it first.
But before you extract downloaded file, we have to decide, where exactly should JBoss files be placed on a file-system. Unfortunately JBoss is not quite conform to Linux File System Hierarchy Standard per default, so there are many possibilities for a location configuration. Some of you may want to place JBoss into /opt directory. But I prefer to split the installation a little bit and want to start by putting JBoss core files in /usr/local/, where local, unchangeable and read-only files usually placed. E.g. I use /usr/local/jboss/510 as JBoss 5.1.0 GA root. So let’s create that location and extract files into it.
mkdir /usr/local/jboss #create new jboss directroy chown jboss:jboss /usr/local/jboss #now its belongs touser jboss and group jboss su jboss mkdir /usr/local/jboss/510 cd /usr/local/jboss/510 unzip /tmp/jboss-5.1.0.GA.zip
At this moment you should have new working JBoss. If you want, test it with
bin/run.sh -b 0.0.0.0
Where -b 0.0.0.0 means that JBoss is listening for every ip address of current machine.
However at this stage the installed Jboss still brakes the Linux Filesystem Hierarchy Standard, so let’s improve this situation.