In my occasional series on waiting for things, I setup a BASH function to wait for AWS CloudFront invalidations. I mentioned it would be possible to invalid and wait in the same function, but was feeling lazy and left it to the reader. Well, I’ve gotten tired of the two step process, so I’m being industrious so I can be lazy.

Here’s about as esoteric a post as I ever write, my love of pushd and it’s little abused directory stack. If you don’t live on the command line, move along, there is nothing to see here.

If you have a lot of SSH keys loaded you may run into the dreaded:

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Received disconnect from 10.10.10.10: 2: Too many authentication failures for spike

This happens because the SSH client tries each key in order, until it finds one that works. The SSH server allows only so many authentication attempts before kicking the client to the curb (default 6, controlled by the MaxAuthTries setting). Fortunately, there’s a fix.

A quickie today on leveraging “the cloud” for warm-ish spare servers.

I run a mix of physical and cloud based servers. The Cloud is convenence, however, in general, I prefer physical servers for lower cost (over time anyway) and greater control. Of course that means having dependency on hardware, upstream connectivity, data center power, etc.

I sometime hedge my bets by keeping a backup copy of the server in AWS.

It’s Boulder Startup Week. With so many tech startups in town, there a lot of focus on code and coders. How do you become a developer? What developer career paths are there? Where do I find work? Etc. Etc.

Coincidentally, my mom, who is pruning, sent me a copy of a letter I wrote, more than 30 years ago now, when I was applying to colleges. It I describe how I first learned to program. I had forgotten this story, but I think it’s relevant and worth sharing.

A couple of posts back, I showed off some functions to pop up notifications when a host became pingable again or when a port became reachable. Today’s (semi) quick tip is how to use BASH’s autocomplete functionality add hostname autocompletion to those notifications functions.

BASH autocompletion is a system that provides tab completion of command arguments. You’re familiar with it’s default behavior which is to complete filenames and paths.

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~ ls enctypt<TAB>
encrypt              encrypt-only-sym.rb  encrypt-time.rb
encrypt-decrypt.rb   encrypt-sym.rb       encrypt.rb
~  ls encrypt

You can override this behavior by providing BASH with a list of possible completions. The list can be a literal list of words, or it can be a function that looks at the current environment ($PWD, user, time on day, etc) and generates context aware list.