Alright, let me tell you about my weekend project, I’m calling it “cocooner.” It’s a silly name, I know, but it kinda fits what I was trying to do. Basically, I wanted a way to quickly spin up isolated environments for testing code. You know, like a little cocoon where my code could hatch without messing up everything else.
First things first, I fired up my trusty old laptop. It’s got all the stuff I need already installed, Docker, Python, the whole shebang. Then, I started thinking about what I actually wanted. I didn’t want to mess with virtual machines, too heavy. Docker seemed like the right way to go, nice and lightweight.
So, I dove into Docker. I hadn’t really used it much before, just enough to get by. I grabbed a basic Ubuntu image from Docker Hub and started tinkering. The idea was to create a Dockerfile that would install all the dependencies my code needed.
Here’s the tricky part: figuring out exactly what dependencies I needed! My test code uses a bunch of libraries, and I kept forgetting something. Installed this, installed that, kept getting errors. It was a real pain. I ended up writing a little script to scan my code and try to automatically figure out the dependencies. That saved me a bunch of time.
Next, I needed a way to launch these containers quickly and easily. I didn’t want to mess with the command line every time. So, I whipped up a simple Python script using the Docker SDK. It lets me specify which Dockerfile to use and then starts the container, runs my test code, and then shuts down the container. Super simple, but it works.
I added some error handling, because, you know, things always go wrong. And I put in some logging so I could see what was happening inside the container. It’s really helpful for debugging.
Ran into a funny issue with file permissions. My test code was trying to write to a directory that it didn’t have permission to. That took me a while to figure out. Ended up having to add a user to the Dockerfile and set the permissions correctly.
Finally, after a whole day of messing around, I got it working! I can now spin up a container, run my test code, and get the results, all with a single command. It’s not the prettiest thing in the world, but it’s a huge time saver.
Here’s what I learned: Docker is awesome, but it can be a bit of a pain to get started with. Also, automating dependency management is crucial. And always, always check your file permissions!
I’m planning on adding some more features to “cocooner” in the future. Maybe integrate it with my CI/CD pipeline, or add support for different languages. But for now, I’m happy with what I’ve got. It’s a simple, effective tool that makes my life a little bit easier.
So yeah, that’s “cocooner.” A weekend well spent, I think.
