Slicehost installation profile - unix

I'm no UNIX Guru, but I've had to set up a handful of slices for various web projects. I've used the articles on there to set up users, a basic firewall, nginx or apache, and other bits and pieces of a basic web server.
I foresee more slice administration in my future. Is there a more efficient way to set up users, permissions, and software on a clean slice than configuration by hand?

It sounds like you can create a new slice from the backup of an existing one. This might not work for you if the slices would be different sizes, different distros, etc. Their forums mention this: Clone a slice?

Depending on the number of machines you might find it makes sense to use something like CFEngine, or Puppet, to configure the new installs.
That brings your work down to configuring each new machine as a CFEngine, for example, client. Then that may be used to install the packages, edit files, & etc.
There are a few articles I wrote on the subject, with a Debian bias, here:
http://www.debian-administration.org/tag/cfengine

Related

How do I upload changed files via FTP? (wordpress)

I'm used to git and command line stuff, but working on a wordpress site freelancing. I have FTP access, but the site I'm working on has like 16,000 files just in wp-content. Is there a way to automatically only upload changed files? I'm using Filezilla and there's an option to do that, but going through 16,000 files takes hours anyway. I know I could use git and do things manually, but that's a pain.
I'm open to suggestions outside of FTP if there's any easier way in general for wordpress dev.
Since you're bound to FTP¹, your options are quite limited. There are free (in limited capacity) services to deploy to SFTP² via git. Some examples: DeployBot, Buddy.works, DeployHQ, etc. There is also Beanstalk, which I've used in the past and it worked rather well, but the free account is limited to 100MB (which would obviously not work for your situation, and it sounds like the client is too cheap to buy a paid account). It is a bit odd to me to store media library in git, but that is another topic and I understand your dilemma.
¹I would highly recommend using the insecurities of FTP as an argument to try to convince the client to switch to... literally anything else.
²Not certain if these services support FTP (as opposed to SFTP). You would probably need to ask, but they may not given the insecurity of FTP.
EDIT - There may also be some open source options like this (albeit old) solution: https://github.com/mehedi101/ftploy (purely as an example; there are others, but they appear to vary in complexity and I have not tried them)

Sass at Multiple Physical Locations

I am about to start a new Sass project where the work will need to be carried out from multiple physical locations on different machines including laptops.
The 1st location is a standard setup with compass etc all running ok.
The second again has compass setup but cannot be networked as such to the first.
The third would be laptops etc.
So the question:
What is the best way to work access the same sass file from all 3 locations ( different times) without carrying a stick or drive around ?
Google drive ?
ftp down load at each?
Also concerned that someone may not get on to the latest version before modifying it.
When any sort of code is going to be worked on in multiple locations, it's always best to use some sort of version control system. Ideally, any time any code is being done, it should use a version control system, but I'll overlook that.
A version control system (VCS) will allow you to make changes in one place, store them in a central place, and then get those changes on other machines. It will also mean you can check what changes were made when, and find what caused something to break a little easier.
There's a multitude of different options out there, and it comes down to whether or not you want to host your own server, use a generally available one, pay a small amount each month to keep servers private etc.
The obvious candidate (being the seemingly current favourite) would be to use git, where you can have your own server or use something like github. But there's also oter options including (but not limited to):
CVS
SVN
Mercurial
Which option you go for will depend on your preference really.
If you are the only one working on the code and don't care much about safety, which versioning systems provide, you can very easily put your project on a Dropbox and set desktop application to sync only selected directories, ignoring others.
I use this method even though I use Git, just because sometimes I just want to not commit changes and continue working on them in different location. I fire up other computer and I am right where I left everything (including text editor settings, plugins, etc.)

Where to start with Xen?

I am a newbie with Xen.I want to know how does Xen work.
It's really a puzzle when facing the code and I don't know where to start.
Are there some easy articles for me?
Since you mention looking at the code, I assume you want to understand the technical details of Xen and not just merely how to start a VM.
As with all problems, start with something simple and then work your way up. Some pointers:
Be sure to have the prerequisite experience under your belt. In particular, strong C and Linux affinity, but also x86 paging and virtualized memory workings.
Make sure you have a sound grasp of the general Xen architecture. For instance, paravirtualized versus hardware-supported virtualization, the special role of the management domain (Dom0) compared to unprivileged domains (DomU), etc.
Investigate the the Xen components running in Dom0:
The Xen control library (libxc) which implements much of the logic relating to hypercalls and adds sugar around these (look in tools/libxc).
The swiss army knife for administrating Xen, namely the Xen light library (libxl). This library replaces the deprecated xm tool with the xl tool and takes care of all your maintenance tasks such as starting/stopping a VM, listing all running VMs, etc. For all these operations, it works in tandem with the aforementioned libxc. (Libxl lives in tools/libxl.)
The Xenstore is a tree-like data structure from which all running domains can retrieve and store data. This is necessary since all I/O goes through Dom0 (not the hypervisor!), and domains need to communicate with Dom0 how they are going to pass I/O along. (Look in tools/xenstore.) You can inspect the Xenstore with a tool such as xenstore-ls.
the blkback/netback kernel drivers which pass the data over shared channels to the VMs. (You will find these drivers in a recent Linux kernel (e.g. >= v3.0) that has so-called PVOPS support).
Take a look at the console daemon (tools/console). Note that sometimes the Qemu console is actually used. Qemu also comes in the pictures as a default backend for if you choose a file-backed virtual storage for a VM.
Experiment with the 'Xen-way' of inter-VM communication: Grant tables, event channels and the Xenstore. With these fundamentals you can create your own shared channel between VMs. You can do this, for example, with writing a kernel module that you use in two domains to let them talk to each other.
I can also give some pointers in the source that you can check out:
xen/xen/include/public/xen.h will give you a list of all the hypercalls with comments what they do.
xen/xen/include/xen/mm.h gives you an introduction to the different memory terminology used by Xen (i.e., real versus virtualized addresses and page numbers). If you don't grasp these differences, then reading the hypervisor code will surely be frustrating.
xen/xen/include/asm-x86/config.h gives an overview of the memory layout of Xen.
xen/tools/libxc/xenctrl.h exports a large list of interesting domain control operations, which gives an abstract view of task division between Dom0 and the hypervisor.
Last but not least, the book 'The Definitive Guide to the Xen Hypervisor' by David Chisnall comes highly recommended. It covers all these topics and more in a thorough, technical fashion with plenty of code examples.
The Xen wiki and developer mailing lists are also a great resource for understanding Xen.
If you have a more specific question, then I can give you a more specific answer.
Here are few links which will guide you with ZEN Start up.Hope they will be useful.
http://www.howtoforge.com/howtos/virtualization/xen
http://wiki.xen.org/wiki/Category:HowTo
http://wiki.debian.org/Xen
For me, that is the best and more concrete tutorial with examples and step by step to start. I used it when I started.
Then you can read a lot more on Xen documentation itself or some books but as a starting point that allows you to easily install and test Xen, I choose that tutorial from Debian Wiki.
If you just want an overview, you may read this: http://wiki.xenproject.org/wiki/Xen_Project_Beginners_Guide.
This will introduce you to Xen hypervisor, suggest configuration to set up virtual machines, provide information about the networking and finally have details about tools for the management of virtual machines.
This documentation is to get the Xen specifically on ubuntu (Most importantly, it works!)
https://help.ubuntu.com/community/Xen
===
However, if you want to go to the next level and understand the working of Xen; Xen architecture, memory management, device management, CPU scheduling etc., I would recommend reading the book "The Definitive Guide to the Xen Hypervisor".

Drupal development workflow for teams

In my last Drupal project we were 5 people doing coding and installing new modules, at the same type our client was putting up content. Since we chose to have only one server for simplicity there were times were many people needed to write to the same files like style.css or page.tpl.php or when someones broken code would prevent others from working
Are there any best practises for a team that works with Drupal? How can leverage code repositories or sandboxes?
A single server may appear to give you "simplicity", but what it gives you, as you've experienced, is utter chaos -- and you were lucky if it didn't result in unpleasant and hard-to-reproduce, harder-to-fix crashes. Don't settle for anything less than a "production" server (where your client can be working -- on content only -- if they like minor risks;-) and a "staging" one (where anything from the development team goes to get tested and tried for a while before promotion to development, which is done at a quiet and ideally prearranged time).
Second, use a version control system of some kind. Which one matters less than using one at all: svn is popular and simple, the latest fashion (for excellent reasons) are distributed ones such as hg and git, Microsoft and other have commercial offerings in the field, etc.
The point is, whenever somebody's updating a file, they're doing so on their own client of the VCS. When a coherent set of changes is right, it's pushed to the VCS, and the VCS diagnoses and points out any "conflicts" (places where two developers may have made contradictory changes) so the developer who's currently pushing is responsible for editing the files and fixing the conflicts before their pushes are allowed to go through. Only then are "current versions" allowed to even go on the staging system for more thorough (and ideally automated!-) testing (or, better yet, a "continuous build" system).
Basically, there should be two layers of defense against such conflicts as you observed, and you seem to have deployed neither. They're both essential, though, if forced under duress to pick just one, I guess I'd reluctantly pick the distinction between production and staging servers -- development will still be chaotic (intolerably so compared to the simple solidity of any VCS!) but at least it won't directly hurt the actual serving system;-).
Here's a great writeup about development workflow in Drupal. It sums everything so far responded here and adds "Features", "Strongarm" and a few more tricks to the equation. http://www.lullabot.com/articles/site-development-workflow-keep-it-code

What is a good method for sharing source code among 3-4 developers that does NOT require it to be Open Source?

I'm a newbie developers and building an application with 3 other remote developers. I've only worked alone until now, and now I need a way to share my source code with the other developers on the project. All of the project sites out there (SourceForge, Codeplex, Google, etc) seem to be aimed at Open Source development I'm not interested in making our code available to the world, I'm just looking for a method of sharing the code among the four of us. What is the best known method...or how is this usually accomplished?
Set up a Subversion repository (can be accessed across http).
There is an excellent online free book detailing pretty much everything you need to know about Version Control with Subversion
Yep, you need a version control repository which is remotely accessible. Subversion is excellent and very widely used; Git is another good option.
You could set up your own repository - you'll need a server which all devs can access via ssh, or via Apache/WebDAV - or use a hosted service, like Beanstalk, Project Locker, Unfuddle, SVNsite, etc.
http://beanstalkapp.com/
Set up a Subvserion repository (http://subversion.tigris.org/). You can control who may view your data through accounts, plus it gives you document versioning. When paired with a Http server, you can even view the source directly in a browser.
Subversion has all sorts of plugins for Eclipse and even Visual Studio, I believe. Tortise SVN is a stand-alone SVN client you may like, although I recommend an IDE-integrated plugin.
Subversion also goes well with a continuous integration server, such as Continuum.
Hosted: http://wush.net is another Subversion hosting platform.
Or, if you can host your own server, check out the VERY easy to use and VERY free VisualSVN Server: http://www.visualsvn.com/server/
You don't say what computing resources you have available, but the easy choice is to use a central server with say SVN to which you all have ssh access using a public key. You can probably rent such a service for around $10 per month.
If you don't like central servers, you can try Mercurial or git and ssh back and forth between your personal development machines.
If ssh is problematic, git actually enables you to send patches to each other by email (probably Mercurial does too). Ben Lynn's Git Magic tutorial explains.
You can use an online source control (like SVN or Git), and share it only with your team members. You should look into Unfuddle, it's a free source control/project hosting, complete with bug tracking system. I use it for my personal projects and it's awesome.
I think the best solution is Subversion. Subversion is a free source control system that is ideal for your requirement.
You can use many other support tools like Tortoise SVN to make the things more easier.
Here is one of the cheat sheets that describes commands of SVN.
Most of the Web hosting providers support easy one click installation of SVN on their servers. ex : Dreamhost So you can get a setup done very easily.
CVS is another Source control system that are used widely but I haven't seen any providers that support easy installation of CVS but there should be. You can have support tools for CVS such as Tortoise CVS as well.
I don't think you are interested in visual source safe (Microsoft Proprietary and not over Web) so I am not going to add information about it here. :)
You need to set up a source control repository. It's a pretty big topic, I'm really not sure where the best place to start reading about it would be. I'm sure the Wikipedia article on Revision Control will at least give you a bit of an overview.
This seems like a decent introductory series as well: Source Control HOWTO
Subversion works just fine over http/https. It is an open source project, but you can use it for whatever purposes you want.
http://subversion.tigris.org/
Most modern source control systems work well. Subversion is a common one. Which operating system will the developers be running?
If you just want to get up and running quickly with something, check out a hosted subversion system like www.beanstalk.com or www.unfuddle.com.
Subversion is open source, and I know you don't need it, but there are a lot of options here. If on Windows, check out Tortoise SVN. If on a Mac and you don't want a command line client, check out Versions.
You can actually setup google code to only allow viewing/editing by registered members. And I don't think they force any licenses either.
We currently use VSS but are in the process of migrating everything over to Source Gear Vault because VSS makes jumping out of our third story windows a common thought...
Here is a free solution with premium options available... https://freepository.com I have not tried this one.
Try github. It will cost you $12/month though.
Just use devunity.com. upload your code via zip or import it from svn and thats it. lets you collaborate around code instantly.

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