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Comment by efficax | Hacker News Reader

Do you have a database, a queue service, a caching layer (or 3), a session store? If all your app needs is an http server then sure, why bother with docker... But if it's more complicated than that, it's great to have standard recipes for alignment in local development, a problem docker solves very well

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These things can also be solved by using distro packages and `cp`-ing config files. Docker introduces a ton of complexity into the stack.

Using Docker to solve these problems is like hiring a construction company to build a birdhouse. Sure, it'll save you the work of having to build the birdhouse yourself, but...it's major overkill, and could end up costing you more effort than other options.

Now, if you were running a complex suite of mircoservices, then there might be a good reason to use containers. But containers are like JavaScript; you shouldn't jump for them before you've weighed your other options.

Reproducibility with a well-written Docker image is well worth it over "cp-ing config files" shiver.

Docker isn't Kubernetes -- it's not that complicated.

cp-ing config files is typically done by using config management like puppet, chef, ansible, or saltstack via templating based on server type, location, etc.

What's so risky about cp-ing config files as opposed to typing "COPY" or mounting a volume in a Dockerfile?

If you use a distro like Debian you shouldn't be worried about breaking changes, especially if you're subscribed to updates/relnotes for the critical parts of your stack (e.g., an announcements mailing list).

Those are good practices to have regardless of your platform.

Docker images aren’t built in a reproducible way unless you use something like Nix to create them

Docker is just a layer on top of cgroups, and Dockerfiles are basically just shell scripts. It doesn't have to be a huge undertaking

Docker and its tightly coupled sibling programs amount to millions of lines of code. It took billions of dollars in funding to make. There's a reason it's classified as a PaaS.

It is far more than a "layer on top of cgroups".

If you believe "Dockerfiles are basically shell scripts", you could try using shell scripts.

Already done https://github.com/p8952/bocker/blob/master/README.md (Docker implemented in around 100 lines of bash.)

The Nix package manager is great for this - the package language was initially a bit more foreign to me than Dockerfile, but the package manager gives the same reproduceability benefits, integrates well with the OS, and being purely functional/immutable let’s you roll the system state back at any time, like Git

You don’t need complex microservices do get some benefits from reproducible production environments. If you have multiple machines and need all of them to have an identical environment, there is no better way. Everything else is ridiculously error prone and complicated. Ever tried to debug why two Java installations have different classpaths? Good luck. Need to upgrade different system level dependencies but your applications needs a specified version? How will you do that?

Docker is like the static typing of deployments. It may seem a bit over the top at first, but it will really make your life easier.

I have most of those things. I just use hosted versions of those things.

Even locally?

In my case, I run all services locally without docker. apt-get seems to work just fine.

Seems a bit brittle.

Oddly, most of this brittle nature helps build a more robust product.

That is, yes, it will break often in small ways. However, most of the breaks will be from version upgrades or machine changes. The sooner you find those, the better.

Most issues are because of changes between software versions. Some very few are because of environment, but that's what a staging environment is for.

Honestly, it hasn't been. Probably helps that I run Linux, but would probably do the same on Mac. Managing that extra virtualization layer has always been more pain than just relying on services that are just always there.

> database, a queue service, ... a session store

I use these three both remote and locally, and start all of these using a simple shell script.

Does the bash script run on Linux, macOS and Windows?

It does if you run it inside a Linux VM.

EDIT: Just to be clear, I am referring to the fact that Docker on Mac and Windows runs inside a Linux VM.

Real men test in production. Others know better.

Everyone has a test environment. The lucky ones have a different environment for prod.

My favorite: "We have a dedicated environment for QA. To save time we also use it for production."

We just had a hosted development database, development redis, etc. It works just fine.

I think you're pointing out the double-edged sword that is Docker; it's very easy to run and experiment with new technologies, even ones you might not be organizationally ready for. The "local" kafka that you used for a proof of concept is now AWS MSK in production.

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