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Base16: proper theming of vim, Gnome Terminal, Sublime Text, Cygwin and more

As a DevOps Engineer, I use several applications on a daily basis, on different operating systems. The ones I use most are vim, Gnome Terminal, Sublime Text, and Cygwin. For a long time, I’ve been having different themes on these applications and frankly, it was driving me crazy. Not only did my eyes need to get used to a different theme all the time; even while using the same theme on some of these applications there were still minor differences in appearance, as none of the themes were identical for all these applications. Being lazy and not willing to fix this myself by designing all the themes by hand, I went to look for some proper ones that could be used in all these applications.

I’ve had a bit of a hit-and-miss relationship with Solarized over the past few years, so I wasn’t necessarily looking for that. Gnome Terminal (or Cygwin for that matter) has always been a bit problematic with Solarized, as the colors weren’t always perfect (especially in htop). With Gnome Terminal being the more problematic application theme availability-wise, I decided to use that applications as a basis for my search. After doing some duckduckgoing (I say: word of the year 2014) for nice themes, I found the base16 project.

Enter the party zone

I was like a kid in a candy store! This project does not only contain quote some themes that have been specified properly; it also has them for a wide range of applications. On top of that, there is a project called base16-builder. This project contains all the color schemes of all the themes included in the bas16 project and lets you generate theme files for a long list of applications. So even if the templates aren’t in the base16 project, you can either generate them with base16-builder or add the theme templates yourself and then generate them!

Right now, I am still impressed with the amount of different color schemes the project includes and how properly they have been specified. It even includes a version of Solarized that doesn’t hurt my eyes in htop. But frankly, due to what’s available in the project, I haven’t been using Solarized anymore. I’m currently hung up on Base16 Default Dark, which I now use as my default theme for all the applications I mentioned before.

Give it a shot and give back

Everybody should try out these themes, as the project has something for everone. If you find a theme template that isn’t complete or not present yet, please add it to base16-builder and add a pull request in GitHub.  The more people contribute, the better this project will be.

Switching hosts – May 2014

Part of the reason for me to start blogging again was to try out a variety of hosts (as in: VPS providers) and share my experiences with them. The first month or so this blog was hosted on a VPS with GreenValueHost (GVH), a really cheap one I may add. After GVH had been bashed and ridiculed at, I thought: let’s try out these guys. The VPS cost only $8/year, so the risk was really limited.

Although the machine felt snappy at first, after a week or so I experienced the occasional lag (as in: really slow disk performance). IPv6 connectivity never worked properly, despite me sending in a ticket and providing plenty of information on what the actual problem was. I me experience, the support I received wasn’t the best. When you send the output of an MTR run with 250 cycles and over 90% of the packages gets dropped at the gateway, I think a provider should be able to figure out where the problem is. Then again, I was paying $8/year for this machine, so I didn’t expect any support as all. The fact that they did respond is good, though that didn’t solve my problem. But the thing that made me move elsewhere was the fact that when GVH’s site was under a DDoS attack, the staff simply went to bed and only came back to look at it the following morning. I don’t expect people to give my any support for a $8/year VPS, but I do expect a company’s “CEO” to at least care a bit.

So, after that month or so, I moved this site to my Xen-PV VPS in Pune, India. I got this machine from Prometeus [affiliate link] when I purchased a load of iwStack credits in December. The performance of the machine is just fine; in fact, it performs really, really great. It being in India does provide a challenge when working on the machine, though. It’s not really close to where I live, so working on the CLI has some minor lag. That’s not a real issue though, as I only need to SSH into the machine occasionally!

For now, India it is. It gives me some time to think about where to move my blog next! Any suggestions are welcome, of course!

The major problem with SolusVM’s IPv6 implementation

SolusVM, the well-known VPS control panel, has supported IPv6 for a couple of years now. There has been one major problem, though: it’s terrible implementation and the consequences of that.

The implementation

SolusVM assigns IPv6 addresses to users by randomly handing out individual IPv6 addresses out of a larger range. Not an actual block; SolusVM requires you to give a set range of addresses from which to generate random ones. This allows the SolusVM Administrator or Reseller to assign up to 200 individual random addresses to an actual VPS.

IPv6 wasn’t designed for individual addresses, though. It was designed to give end users a block of addresses, the smallest one being a /64. The reason behind this being that the last 64 bits of the 128-bit IPv6 address are used as the interface identifier. It defines a unique interface inside a network, a subnet. This ensures that wherever an interface is, the last 64 bits should never have to change, only the first 64 bits, meaning an address inside a network is theoretically always available. This makes NAT completely unnecessary. More importantly, though, the last 64 bits are used for several IPv6 features: Neighbor Discovery (ND), Stateless Address Autoconfiguration (SLAAC), privacy extensions, and others. Not having a /64 assigned prevents people from using those features.

The problem

With SolusVM not assigning /64 blocks to end users they not only not get all the features of IPv6. They get a free problem with it: incompatibility with those that do use those features.

The best example of this is Google Mail. When you have VPS backed by SolusVM (no matter the virtualization technology) and with statically assigned random IPv6 addresses, you cannot send e-mail to Google Mail addresses using IPv6! Why not? Because the addresses you have come from a /64 (or worse, even smaller) and all your friendly neighbors who have a VPS with IPv6 addresses from that same block, will probably also try sending mail. Google Mail just looks at the /64 when receiving mail via IPv6 and notices that there is a lot of activity coming from that block. No wonder, because there could literally be hundreds of servers with an address from that block of IPv6 addresses. So, Google Mail considers it SPAM and starts blocking every address from that entire range. The result: you either have to disable IPv6 on mail sent to Google or you cannot send mail to Google using IPv6 (your mail server determines which address to use, IPv4 or IPv6).

And that’s just one example…

The solution

SolusVM should start implementing IPv6 the way it should have been years ago: giving users the option to assign a /64 to their VPS and then enable addresses from that /64 to the VPS (so they are actually available in the VPS). This way you don’t have to assign millions of unused addresses to the server and you give the users an address block that is in accordance with IPv6’s design and implementation. It will not only solve the Google Mail problem, but also other (and potentially future) problems.

Hello world!

Welcome to my blog! It’s been a while. I’ve decided to write blog posts regularly again, either long or short, on a variety of topics. This website will also contain some more information about who I am and what I do.

For now, this will have to as the first post.

Hello world!

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