Archive for the ‘Linux’ Category
LibreOffice hot off the presses for Ubuntu and now in PPA!
Posted by: jeffro in Linux, Software, Technology on March 1st, 2011
In case you haven’t heard, LibreOffice is available as a PPA. That means no more downloading individual .debs and auto updating! Found through OMG!Ubuntu here.
You can never really escape it
I enjoy running Linux, not only because I am sort of a fanboy about it, but I have been running it long enough to be much more proficient in it when compared to anything else. There are things that drive me nuts about it, just there are with anything. In my job, I am a front-end/UI developer. Not a designer, mind you, I am not terribly good at dreaming up good user interfaces, but I am good at implementing them. This is in the web-based world also I have to add. So that brings me to the biggest gripe I have about my profession, browser differences, or more specifically Internet Explorer.
I have the pleasure of being able to run Linux on my workstation, but I still have to keep a Window partition around so I can reboot occasionally and check my work in Internet Explorer. Usually there aren’t a lot of issues to correct for it to layout right in IE, but sometime there are major problems and I find myself spending the whole day in Windows. *sigh… I guess you can never really escape
Let me introduce you to my little friends
Posted by: jeffro in Linux, Software, Technology on December 22nd, 2010
I installed Linux on my workstation this week and I have been ‘rediscovering’ some useful apps.
First off, guake, yet another drop down terminal, but this one works surprisingly well. Its simple, but does just what it needs and nothing more. Apps like this are few an far between, since everyone tries to get their apps to rollover and fetch the newspaper too. Get this one if you use the terminal a lot.
Then there is Docky, I think I am just about the last person to have found this pretty and a useful system panel, a la OSX. Mac-ites should’t get all the cool apps.
And, why-oh-why does the default Ubuntu desktop come with Empathy rather than Pidgin for IM? I could go on about how incomplete and buggy Empathy is, but I think everyone already knows that…except for the Ubu-devs..
Maven, I think I know what this does..Its a..ahh, no, actually I am not even sure why I threw it in here. I have been it a lot lately and I am not sure if I am repulsed by it or intrigued..I have narrowed it down to either being the salvation of Java developers, or damnation wrapped in nicely formatted XML. I dunno, you decide..
Ok, so this list wasn’t nearly as long as I was thinking it was going to be..
The resurrection of RobbinsWeb
I have small linux server under my desk at home that has been chugging away for the past 3 years with nary a peep. Two weeks ago when I entered my office I was presented with the distinct smell of something burning. The smell was emanating from from ole’ trusty. I never realized how much I depended on this little machine until it stopped. No more OpenDNS updates to keep the kiddies safe on the internet, no more dynamic IP updates, no more backups, no more proxy server (for those ‘special’ occasions), no more playing Gearhead at work! I felt like I had lost a close friend, or at least a favorite pet.
Now, three weeks later, a new power supply, RAM, and a mess of case fans, RobbinsWeb lives again. *sigh…welcome back buddy
Lighttpd can’t bind to port 80
If you are running Ubuntu 10.01 and you get the error message “can’t bind to port: :: 80 Address already in use” when you try to start up, check your config file and comment out the line that has ‘ include_shell “/usr/share/lighttpd/use-ipv6.pl” ‘
Just some advice from my wanderings.
Of bash and LVM
Posted by: jeffro in Linux, Technology on October 5th, 2010
Wow, has it actually been 2 months since I posted anything to this site? I suppose it has.. What has kept me busy you might ask? Well, I have been working on my backup script rather faithfully lately due to some unfortunate happenings at work lately, more on that later. I have introduced a simple database dump feature to the script so it can dump a database (mysqldump) into the directory it is backing up, then you get a nice bundled backup in one shiny tarball!
At this point I am pondering how to keep the script from turning into a massive procedural nightmare of bash code. Sure, it does everything I need it to do right now, but adding features could prove to be an exercise in masochism if I had to do anything major. Right now the script it sitting at 357 lines of code, a lot of which is debugging output, so in reality the script it probably closer to around 250 lines, but the whole thing it still bigger than I anticipated it getting. Bash has turned out to be surprising powerful, but surprisingly limited. I suppose it was never meant to be used as a full programming language.
At this point I am trying to figure out how to get a single instance of the script to backup multiple directories into separate tarballs. The only thing I have been able to come up with thus far has been a separate configuration file with some sort of structure to define each backup job. I will probably go this route, but not before I have exhausted other options first.
Ok, back to the unfortunate happenings at work. One of our web servers runs CentOS, if you have read any of my previous posts you will know that I absolutely adore CentOS…wait did I say adore, I mean despise. When I got the colocated server CentOS had already been set up on it so I just went with it. Little did I know, they enabled the Linux Volume Manager to manage the disks. I applied a routine kernel upgrade, then rebooted and the machine died a horrible silent death right then and there. It never came back and never relinquished any of the data off the drives, even though I was running the drives in Raid 1. FSCK basically came back with a “Your screwed” error message after trying to read the Volume groups for a couple of hours. How did this happen, I have no idea. I do know that this was the worse server melt down in my entire history of being an admin, and it was also the only time I have ever ran CentOS with LVM in a production environment. I am open to the idea that it might be possible that I did something in the recovery effort to completely hose all the data. However, take a guess at who I am blaming for the whole fiasco 
You don’t know how much junk you have until you move
Here is the situation, I need to move a website running from server A to server B. Server A is starting to show its age and need some upgrades (hard drives, RAM, and OS). I needed to move a very important web site from server A to server B, so we can take down A for an extended period of time. So after using my best buddy rsync, all the files are in place on server B, all I need to do is point all the services that used to point to server A now will be pointed at server B. Easy right?
Try number 1; Rsynced all files to server B, flipped the switch and realized that something was wrong with the SMTP server, and I would need to flip it back to make the corrections. 1 day lost..
Try number 2; Rsynced all files to server B (there are people actively adding files to this server throughout the day); flipped the switch, and realized that I never installed a custom backup program that was running on server A, crap, I can’t find the source, flip it back to do some searching. Another day lost..
Try number 3; Flipped the switch, then found that the version of PHP installed on the new server had some issues with the CMS software, and I forgot to rsync the files over before I flipped the switch, crap! Flip it back to do some research on the issue. 1 week lost while I tracked down the issue with PHP 5..
Try number 4; Rsynced all the files to server B, flipped the switch…waited for the other shoe to drop…crawled out from under my desk and looked around, everything was running, nothing was broken..I am fully up and running on server B now.
I really should have written down everything that was required since I am going to have to move the site back to server A soon…
Great post on relaying Postfix through Gmail
Posted by: jeffro in Linux, Technology, Web on March 6th, 2010
I was setting up a home server and I wanted to relay postfix through Gmail, but I was having a terrible time getting it to work. I found this site that explains it very simply. Should take you longer than 10 minutes and you will be realying to your hearts content…provided you have a GMail account 
http://www.felipe-alfaro.org/blog/2009/05/10/have-postfix-relay-e-mail-to-gmail/
CentOS, let me count the way I hate thee
First, the default IPTables configuration is just plain stupid. Seriously, everyone I have talked to about this recommends flushing all the default rules and starting from scratch. Even the CentOS wiki recommends this procedure. I understand this might be a RedHat thing, but seriously, change it in the default config if all you are going to do is recommend everyone throws it out once setup is complete. Yes, I am referring to the esoteric RH-Firewall-1-INPUT chain..
Second, unless I am running some enterprise government high-load zombies-at-the-door, the end is nigh server, enabling SELinux by default is over-kill. No seriously, if you wanted to make a more secure system, take a page from the Ubuntu server playbook and try disabling some services on default setup. Do I really NEED printing capability on a headless server that is most-likely running in a remote NOC somewhere? Then there is avahi, seriously!?, on a server?? Did the decision to include that in a default SERVER install come from the Playskool development team? I spent an hour ripping the guts out of needless services installed by default.
Third, and this may be applicable to RedHat-based distros in general. But not including core functionality in the PHP RPM is just…well, I am at a loss for words here. Thank you ever so much to http://benlancaster.wordpress.com/ for his writeup on Installing PHP’s JSON extension, I would have been totally lost with out it. Unfortunately, it just underlines the issue..
Posix ACL’s
I manage to get a used HP DL380 and a bunch of big drives (did I write about this already?) And my first instinct was to immediately put Linux on it, then figure out what to do with it later. After a moment I realized that most of the servers were filling up their drives and a file server would be an excellent addition. Then I also realized that most of the servers were Windows-based and everyone authenticated against Active Directory. Hmm, I had never set Samba up to authenticate against AD before, this sounded like a sweet challenge.
I am writing up a tutorial on what I did to get everything working, everything was fairly straight forward until I started to tack down the access lists. At first I thought I would limit directory access through the Samba ‘valid users’ option, but that was too limited, since I would need nested permissions, and I wasn’t about to create shares for EVERY nested directory that needed special permissions. What I did end up doing was allow everyone to see all the shares, except some super secret ones where the management keeps the cheat codes to their video games. But rather than control access through samba I would do it all through ACL’s on the file system.
If you haven’t used ACL’s on a Linux system, don’t worry I am guessing many haven’t. Rather than the vanilla UGO perms of the standard Linux file system, you can get much more granular in who can see and do what. Its still RWX based but you can specify multiple users and groups and their specifics perms per directory and file. Everything is controlled through the commands ‘getfacl’ and ‘setfacl’. I am writing some wrappers around these to simplify their usage, since I am going to have to teach a couple people at work how manipulate permissions. I will post it when I have something more. Might get a tutorial in with it too. 
