Braindump » Linux

Ubuntu for 30 Days – Day 3 thru 10

clamasters — Tue, 14 Jul 2009 02:30:12 +0000

I was a little busy with work and baby prep so I really wasn’t on the computer all that much however, I am really liking the shear number of applications that are at my finger tips. I started using workspaces a bit more. At home I only have a single 17″ monitor, I know I know. Hopefully it’s only temporary. I’m used to having duals at work so it’s a bit of a change.

I will say that I am liking Rhythmbox as my music player and started using Miro for my video podcasts or videocasts…whatever you want to call them. I really only watch Hak5 so far but I’m sure I’ll be adding more in the future.

I had been having some problems staying connected to my VPN at work via the Cisco VPN app so I really haven’t been interfacing to my work from home a lot except from my eeePC. I want to do a site to site from home to work but I’m sure my employeer wouldn’t want that. Sorry for the boring update, hopefully some good stuff coming up.

Ubuntu for 30 Days – Day 2

clamasters — Fri, 03 Jul 2009 04:37:00 +0000

Until about an hour ago, tonight’s Ubuntu experience was “meh”. I really couldn’t think of anything that I actually wanted to do. I then remembered that the pictures needed offloaded from our camera from Jessica’s baby shower. After a little wrestling with a bad cable connection (camera’s fault) I was greeted with a happy to import greeting from “f-spot”. For such a simple application it has some neat features including the ability to export as a gallery which I like to do from time to time. Here is a quick example. I do have to say, the photo management in f-spot is pretty good. I still went ahead and installed the Ubuntu package for Picasa. I use the web albums as a backup for any of my photos so it makes sense. It appears that all the features of the Windows version are in the Linux version as well so no lack luster there.

I’m still enjoying the simplicity of Rhythmbox as the music player. Connected to last.fm it plays much like Pandora does and I really like the popups to let me know what song/artist is playing.

Doing my everyday tasks (gmail, wordpress, etc.) really is not effected by the use of Ubuntu as they are all browser based. I upgraded my install of wordpress today and needed an application like WinSCP for Ubuntu. Turn’s out that it’s built in. NEAT… Go to “Places” –> “Connect to Server” then using SSH as the connection type I was given a file/folder manager access to my server via SFTP/SSH.

So far so good.

Ubuntu for 30 Days – Day 1

clamasters — Thu, 02 Jul 2009 04:05:07 +0000

Tonight was a little rocky for Mr. Ubuntu. I was trying to help my father out with an Outlook Express issue obviously on a Windows machine. My typical remote access solution would not work as it requires Windows as the support PC. However, I went ahead and tried to do a terminal server connection to a server on his network and then launch the application. In this case ShowMyPC. The connection was SLOW!!! I then started searching around for something that was cross compatible. I found YuuGuu but apparently am too dumb to figure it out.

Does anyone have a recommendation for remote support TO Windows and OS X workstations and servers FROM linux? Preferably Ubuntu. I prefer free solutions but would be willing to pay a small fee if needed as long as it also supported support from Windows as I could use it from my job.

On a softer note, I do like RhythmBox. I want to get Pandora playable inside there but that can come later.

Setting up VPNC and the Network Manager VPN piece was pretty easy. All through apt-get… I needed this to connect into my work place and do time entries and remote support stuff.

So far so good. With the exception to remote support to Windows based clients, I’m pretty rock solid on Ubuntu.

5 Minute Cron Tutorial – Linux Task Scheduler

clamasters — Wed, 20 Aug 2008 02:34:32 +0000

Cron is an exceptionally useful tool in the Linux world where administrative tasks can easily be rolled up into shell, php, perl, and python scripts among other things. Per a website that I just came across, the word cron comes from the Greek word chronos which means time.

First, lets setup the environment. I use VI as my text editor on Linux and you can view my “60 second VI tutorial” on here as well. To ensure that VI will be our crontab (cron table) editor we will need to edit your “.profile” file for whatever user you are going to be logged in with (typically root).

vi /root/.profile

Add one of thefollowing lines above the second fi to match your preference.

export EDITOR=/usr/bin/vi #if you have just VI installed export EDITOR=/usr/bin/vim.basic #if you have VIM installed

Ensure that you save it with :wq.

Now that we have that out of the way, lets start scheduling tasks.

Since backups are traditionally something that you would want to automate or schedule, I’ll use it as my main example but first I’ll break down the cron scheduling syntax.

Field	Meaning (input)
1	Minutes (0-59)
2	Hours (2-24)
3	Day of the Month (1-31)
4	Month (1-12) January thru December
5	Day of the week (0-6) Sun thru Sat
6	User to execute the command
7	Command to execute

0 2 * * * root tar czf /var/backup/www.tar.gz /var/www >> /dev/null 2>&1

With the above example and the table of what each field does, you get can put together that at 0200 or 2:00 AM every day root will be running “tar czf /var/backup/www.tar.gz /var/www >>/dev/null 2>&1″ which is telling tar to tar up /var/www into /var/backup/www.tar.gz and /dev/null 2>&1 is a way to have the command put any output into a “trash can” if you willÂ Alternately you can specify a log file for that output to go with “>> /var/log/cronforcommand.log 2>&1″.Â The * in a schedule means to omit that portion of the schedule.

That one was pretty basic so I’ll get a little more complicated now.Â Matter of fact, I’ll just skip the user and command to execute from now on and focus on the command structure for scheduling with cron

EXAMPLES:

Every Minute – * * * * *

Every 5 Minutes – 0,5,10,15,20,25,30,35,40,45,50,66 * * * *

Every 5 Minustes (Simple) – */5 * * * *

Every Hour – * */1 * * *

Every 2 hours – * */2 * * *

Every Day @2:00 AM – 0 2 * * *

Every Day @ 6:00 PM – 0 18 * * *

Every Sunday @ 3:15 AM – 15 3 * * 0

On Feburary 11 @ 10:00 PM – 0 22 11 2 *

That pretty much covers the majority of typical uses for cron. Obviously this is a very powerful tool and can do so much more but for this post, I think it’ll do.Â If I messed anything up , please let me know.Â Enjoy.

Excelent Time Management Video – Randy Pausch

clamasters — Mon, 11 Aug 2008 20:17:58 +0000

At work, I find it somewhat hard to stay on task.Â I like it when I get real material things that can help manage my time.Â One of they guys I work with sent me a link for this lecture by Randy Pausch.Â As he recently passed due to cancer, this speaks volumes for his character as he had approximately 3 months to live at the time of this talk.Â Please enjoy.

Apache2 on Ubuntu – OpenSSL CSR / Self Signed Cert

clamasters — Wed, 30 Jul 2008 19:49:27 +0000

Seventy-five percent of the servers I have been working on over the last few months have been Linux. Mostly Ubuntu. This due to the fact that my company has allow me to start migrating over and building new servers on this platform. With that, we need secure ways to access the servers. On occasion I’ll use webmin but mostly just SSH and whatever website is running on it (management, applications, etc). Webmin takes care of itself with a self signed certificate and SSH creates its own keys. Pretty easy there. Now, for the website that is running on the box, out of the gate it’s unencrypted TCP/80 traffic running from an Apache 2 web server. This short tutorial will cover how to create a CSR with OpenSSL for use when getting a certificate from one of the CA’s. I won’t explain everything here but you may use Ubuntu’s https-help guide if you need more info found here.

First, let’s make sure we have the right packages installed.

apt-get install openssh apache2 apache2.2-common php5

Now let’s enable SSL for apache2

sudo a2enmod ssl

Now lets create the server SSL key.

cd /etc/ssl/private
openssl genrsa -des3 -out dns.server.com.key 1024

Ok, now that we have the key, let’s create the CSR to be given to the CA.

openssl req -new -key dns.server.com.key -out dns.server.com.csr

It will prompt you for the passphrase and some other bits of information. The most important one is site name. This must match the name of your server. Something like mail.domain.com or www.domain.com would be appropriate here.

The CSR can now be uploaded to whatever CA you choose. I use GoDaddy because they are so cheap.

If you do not want to purchase a certificate you can create your own self signed cert with the following command.

openssl x509 -req -days 365 -in dns.server.com.csr -signkey dns.server.com.key -out dns.server.com.crt
cp /etc/ssl/private/dns.server.com.crt /etc/ssl/certs

Now that we have the cert created, let’s configure Apache to use it. Add the following 3 lines to your website configuration. The default one is located in /etc/apache2/sites-available/default.

SSLEngine on SSLCertificateFile /etc/ssl/certs/dns.server.com.crt SSLCertificateKeyFile /etc/ssl/private/dns.server.com.key

Save that config file and enable Apache to listen on 443 for HTTPS traffic. Add the following line to /etc/apache2/ports.conf

Listen 443

Restart your Apache2 process and you should have a fully functional SSL enabled website.

/etc/init.d/apache2 force-reload && /etc/init.d/apache2/restart

60 second vi intro

clamasters — Wed, 30 Jul 2008 18:53:05 +0000

vi is neat.Â Most of the engineers I work with like nano or pico but I like vi.Â For some reason it makes me feel more like a geek when I’m using it.Â In fact, I’ve been using it so often lately that I have been trying to use vi command in notepad (obviously without success).Â This tutorial will cover only the basics but that should be enough to get you started.Â A much better tutorial is available here.

vi /etc/network/interfaces - opens /etc/network/interfaces in vi

i - insert / - search G - [Shift] g - go to bottom of page dd - delete the line d <- or d -> - d [left or right arrow] delete 1 character in that direction 10G - 10 [Shift] g - move to line 10 (obviously number can be replaced) 10dd - delete 10 lines from cursor and below (again, number can be changed) :q - quit (no changes may have been made) :q! - quit (do not save changes) :wq - write quite (save and quit) :w - write (save)

Ok, now that you have mastered the basics of vi, please refer all other needs to the link provided above.Â Hope you like vi as much as I do.

NOTE:Â Ubuntu (and maybe debian) have a few things that the built in vi program have that seem a little strange.Â I usually install vim just to be safe.Â to do this run sudo apt-get install vim-full.

Getting Ubuntu Ready for “REAL” use…

clamasters — Sat, 31 May 2008 05:49:40 +0000

I love Ubuntu…it’s undubitably the best free OS on the planet. However, there is one thing that I absolutely hate about Ubuntu.. My inability to SSH into the system from anywhere. I know it is this way by design and that it’s a “security” feature but it still annoys me. So the following commands are what I use to get the system ready for use after a fresh install.

apt-get install openssh-server openssh-client

That’s it. If you want to play around a little more you can configure Ubuntu’s firewall in just a few simple steps as well. In my example I will enable tcp/80, tcp/443, tcp/22 and udp/53 inbound.

ufw disable
ufw allow 80/tcp
ufw allow 443/tcp
ufw allow 22/tcp
ufw allow udp/53
ufw enable

And then you can validate what you have entered with:

ufw status

The output will be similar to this:

Firewall loaded

To Action From
– —— —-
80:tcp ALLOW Anywhere
443:tcp ALLOW Anywhere
22:tcp ALLOW Anywhere
53:udp ALLOW Anywhere

And that’s really all I do…it’s definately not much but it will be enough to get you started connecting remotely.

Switchvox PBX replaced my trixbox

clamasters — Fri, 28 Mar 2008 03:42:00 +0000

This was a pretty quick change but one of my friends recommended that I try out Switchvox which is an IP PBX build on Asterisk and is owned by Digium. I took a few looks at the webpage and I was pretty much sold. It looked so easy (and pretty). I installed it on a separate machine that I just picked up from a school district that was getting rid of PC’s for dirt cheap from an old computer lab. The setup was almost the same as trixbox but had fewer questions for me to answer making it simpler overall. Once installed, the first thing that I noticed was the SSL based access to the box was the only way to manage the server. This was cool and questionable at the same time as command line traditionally is the easiest/best way to debug anything. Well, I logged into the server with my friend on the phone, added in my Teliax information and in 2 minutes I was able to call out. This was amazing in my opinion. Something this easy has to come with a price tag. Nope, I’m using the free edition…with a big smile on my face. A few minutes later and I was able to call through my provider from my cell and hit voicemail (that was already setup). The setup of dial plans, providers, hardware interfaces, and extension is SO EASY. Much easier than trixbox and I thought it was easy. Switchvox even auto detected my Sipura SPA-1000 device. At this point I was completely sold. To be honest, the only complaint that I have at this point is the inability to go to command line to debug stuff. That’s it. I would recommend this product to any home or small business.

trixbox now working

clamasters — Thu, 20 Mar 2008 16:01:26 +0000

Well, a few weeks ago I really wanted to get a home phone setup for my house. My wife an I have been using our cell phones for pretty much everything for the last 2 years and thought it would be a good time to get something else. So instead of taking the easier route with a telephone company, I chose to setup Asterisk on an old extra computer with a Sipura SIP converter connected to a traditional home phone. My VoIP provider is TelIAX out of Colorado and so far has been pretty cheap. I would say the support isn’t the best but as long as you know what you are doing, the system is always online. The real reason I chose them was their IAX2 support. I didn’t want to have a huge number of ports opened on my firewall to allow SIP to work. Also, traditionally SIP has not been the nicest with NAT though Asterisk does a pretty good job with that issue.

Instead of going command line or even installing the package manually, I chose Fonality’s trixbox CE which is free and is an all-in-one solution for IP telephone. At least on the server side. Install is straight forward, answer a few questions and it’ll eventually reboot and you’ll have a functioning Asterisk server with FreePBX installed as well as some other goodies.

Once you have trixbox up and running, you login to the web GUI and start configuring. Mine is http://192.168.1.10. Under FreePBX I had to configure 3 things:

1. Trunk – This is to tell Asterisk who to connect to for inbound and outbound calling. You have to configure things like registration strings, usernames, passwords, and any specific information for your provider. I have attached my configuration to this post.

2. Extension – I created a new extension (201) to allow my Sipura SPA-1000 to register to my trixbox. The setup on that was fairly easy with just an extension number, password and a few options for voicemail and fax.

3. Inbound/Outbound routes – Tell Asterisk to use a specif trunk for outbound calls and specify what dial patterns you want it to pick up on. Then on inbound you need to tell Asterisk what extensions to ring when a call is coming in.

That’s it. Really, really simple. This was not my first time with trixbox but it was the first time that I actually got it to work. I was quite surprised how clean the calls sound through the Internet, I was expecting to need to do QoS to get it right. I’ll still do that but so far I have not needed to.

My next goal is to get some of the advanced features running. Music on hold, failover call routing, etc.