Category Archives: PCs (and Macs)

Windows, rsync and permissions

Just a short note on mixing Linux utilities with Windows. I wanted to set up a single button deployment of updates to a static web site. I had been using an rsync script, but it required me to manually enter authentication credentials every time it was used to send updates to a remote Ubuntu server.

I set up public key authentication, but it would not work with the permissions of the key files on the Windows machine where the updates were coming from. After struggling with this for a bit, I finally used Cygwin running on the Windows machine to set the permissions just as I would on a Linux system. After that, things worked fine — it’s a single click script with no intervention required.

Still don’t know how to get this done using Windows only. Too lazy to figure it out.

An Email Server on Ubuntu 14.04

Email is pretty old. It is older than the Internet. Despite the perennial claims that email is “dead”, it is still going strong. It’s also a bit complicated, which is why most folks set up an account with someone else (Yahoo!, Gmail, HotMail, ProtonMail, FastMail, etc.) who can take care of it for them.

However, if you want to host your own server, it can be done. If you are running Ubuntu 14.04 (and only that version at this time), MailInABox can handle most of the setup for you automatically.

It takes care of things like anti-virus, anti-spam, grey-listing, and HTTPS for you. The one area it cannot handle for you is the DNS setup. That’s something that is typically done with the domain registrar. And it seems to be different at each one, although there are tutorials appearing on the MailInABox web site that walk through the process at specific registrars. That was really the only difficulty I had.

There may be other problems getting other email services to accept email from your new server. They each have some arcane heuristic rules that block email before it even reaches their spam filters.

So, if you’re tired of having all of your email read just to send you more advertising, think about setting up your own server. It isn’t that hard anymore.

ssh Cleverness

Just a quick note about using SSH. Recently I had to wipe and re-install Ubuntu. (More on that later.) That meant my ssh private key was wiped as well. In order to replace it, I copied the file from a Windows machine onto my newly installed Linux partition.

When I tried to log into some of my other servers, ssh gave me a warning about lax permissions and refused to log in without my password. Very clever. I never even thought to check the permissions of the file I copied over.

Setting the correct permissions:

chmod 600 ~/.ssh/id_rsa

fixed the problem.

Cloud Storage at Copy

I use the Cloud very simply, nothing elaborate. I use BitBucket to keep track of my repositories. I use DropBox to store copies of scientific publications and Fargo outlines. For important stuff, I use SpiderOak because of its great security model. I think I have an iCloud account somewhere. That’s it.

This morning, I’ve been playing with a new service called Copy. It is very much like DropBox but starts you out with much more storage, 15GB instead of 2GB. And you can get bonus space by referring other users. For example, if you click the link above and sign up, we will both get an extra 5GB. If you get a few of your friends to sign up, that can add up to a lot of extra space.

If you share items with other people, Copy splits the charges equally amongst all the folks being shared with. For example, if there is 30GB of data being shared by three people, each is charged for only 10GB. Nice.

If you want more storage than you can get for free, you can sign up for a couple of levels of paid service. The rates aren’t bad.

There is an API for deploying apps against. Still reading, but it looks reasonable.

Not really sure yet about the security aspects and other details (is storage versioned? storing only diffs? what happens to deleted data?) But things don’t look too different than DropBox.

The only problem that I’ve had with the service is that the Windows version of the application will not recognize my user name and password. The web and iPad app have no problems. Haven’t tried the Linux client yet.

Overall, this seems like a very nice addition to the cloud storage space.