More Virtual Machine Development
I’ve written before developing on OS X using virtual machines. That was ~6 months ago and it seemed time for an update.
Docker is Better
One thing that has improved is Docker. Docker Compose now works on OS X. Docker Machine also has become more stable, which allows a boot2docker like experience on any “remote” VM where “remote” includes things like cloud servers as well as Vagrant VMs.
In terms of development, Docker Compose seems really nice in theory. You can define a suite of services that get started and linked together without having to manually switch configs all over the place. Eventually, Docker Compose will also be supported on things like Docker Swarm, which means, in theory at least, that you could deploy an entire stack.
In practice though, the linking is not as robust as one would like. If a container doesn’t start, the link doesn’t get added to the host machine’s /etc/hosts file. It’s also unclear how portable this is across different distros. While an /etc/hosts file is pretty standard, it still must be used by the OS using whatever resolution system is in place. I’ve gotten the impression that things are moving towards injecting DNS in the mix in order to avoid lower level changes, but time will tell.
While it hasn’t worked for me, I’m still planning to keep trying docker compose as it seems like the best solution to starting up a suite of microservices for development.
Docker and Emacs !?!
Emacs has a package called Prodigy that lets you manage processes. I also played around with running my dev environment in a docker container where I just used Prodigy to run all the services I need as subprocesses of the Emacs process. It is like a poorman’s emacs init system. Alas, this wasn’t much better than working on a cloud server. While it is clever and portable, it still is like ssh’ing into a box to work, which get frustrating over time.
Vagrant and rdo
A while back I released a tool called rdo that lets you remotely execute commands like they were local. This has become my primary entry point into using Vagrant and avoiding having to use a terminal to access my dev environment. I also integrated this into my xe tool to make things more cohesive, but overall, it is easier to just use rdo.
Even with a reasonably efficient way to make VM development feel local, it’s still a little painful. The pain comes in the slowness of always working through the VM. Vagrant shares (by way of VirtualBox shared folders) are slow. I’m looking at using NFS instead, which I understand should be faster, so we’ll see. The fastest method is to use rsync. This makes sense because it basically copies everything over to the VM, making things run as “native” speeds. My understanding is that this is a one way operation, so that doesn’t work well if you want to run a command and have the output piped to a file so you can use it locally (ie dosomething | grep “foo” > result_to_email.txt).
I also spent some time developing on a cloud server. Basically, I set up an Ubuntu box in our cloud and ssh’d in to work. From a purely development standpoint, this worked pretty well. I used byobu to keep my emacs and shell sessions around after logging out or getting disconnected. Everything worked really fast as far as running tests, starting processes and even IRC. The downside was the integration into my desktop.
When I work in a local Emacs, I have key bindings and tools that help me work. I use Emacs for IRC, therefore, I have an easy key binding to open URLs. This doesn’t work on a cloud server. What’s more, because I’m using Emacs, any fancy URL recognition iTerm2 often gets screwed up where I can’t click it, and in some cases, I can’t even copy it. Another thing that was problematic was that since the cloud server used a hypervisor, I couldn’t run VirtualBox. This meant no Chef Kitchen, so I was forced to head back to OS X for doing any devops work. Due to firewall restrictions, I also couldn’t access my work email on my cloud server.
Lastly, since the machine was on a public cloud, running any process was usually available to the public! In theory, these are just dev processes that don’t matter. In practice though, spinning up a jenkins instance to test jobs in our real environment, was dangerous to run openly.
The result was that I had to make a rather hard switch between pure dev work and devops work when using a cloud server. I also had to be very aware of the security implications of using my cloud server to access important networks.
Sidenote: Emacs in the Terminal
Emacs through a terminal, while very usable, has some nits related to key bindings. There are far fewer key bindings available in a terminal due to the shell having to provide actual characters to the process. While I tried to work around these nits, the result was more complex key bindings that I had no hopes of establishing as habit. One example is C-= (C == ctrl). In reStructuredText mode, hitting C-= will allow cycling through headings and automatically add the right text decoration. Outside rst-mode, I typically have C-= binded to expand region. Expand region lets me hit C-= repeated to semantically select more of the current section. For example, I could expand to a word, sentence, paragraph, section, and then document. While these seem like trivial issues, they are frustrating to overcome as they have become ingrained in how I work. This frustration is made more bitter by the fact that the hoops I’ve jumped through are simply due to using OS X rather than Linux for development.
I’m not going to give up just yet and install Linux on my Macbook Pro. I’m doing some work with rdo to allow using docker in addition to Vagrant. I’m also confident that the docker compose and network issues will be solved relatively soon. In the meantime, I’m looking at ways to make rdo faster by reusing SSH connections and seeing if there are any ways to speed up shared folders in Vagrant (NFS, Rsync).