If I’m okay with the software (not just trying it out) am I missing out by not using dockers?

No, I think in your use case you’re good. A lot of the key features of containers, such as immutability, reproduceability, scaling, portability, etc. don’t really apply to your use case.

If you reach a point where you find you want a stand-alone linux server, or an auto-reconfiguring reverse proxy to map domains to your services, or something like that - then it starts to have some additional benefit and I’d recommend it.

In fact, using native builds of this software on Windows is probably much more performant.

Containers can be based on operating systems that are different to your computer.

Containers utilise the host’s kernel - which is why there needs to be some hoops to run Linux container on Windows (VM/WSL).

That’s one of the most key differences between VMs and containers. VMs virtualise all the hardware, so you can have a totally different guest and host operating systems; whereas because a container is using the host kernel, it must use the same kind of operating system and accesses the host’s hardware through the kernel.

The big advantage of that approach, over VMs, is that containers are much more lightweight and performant because they don’t have a virtual kernel/hardware/etc. I find its best to think of them as a process wrapper, kind of like chroot for a specific application - you’re just giving the application you’re running a box to run in - but the host OS is still doing the heavy lifting.

I was using file merging, but one issue I found was that arrays don’t get merged - and since switching to use Traefik (which is great) there are a lot of arrays in the config! And I’ve since started using labels for my own tooling too.

I was recently helping someone working on a mini-project to do a bit of parsing of docker compose files, when I discovered that the docker compose spec is published as JSON Schema here.

I converted that into TypeScript types using JSON Schema to TypeScript. So I can create docker compose config in code and then just export it as yaml - I have a build/deploy script that does this at the end.

But now the great thing is that I can export/import that config, share it between projects, extend configs, mix-in, and so on. I’ve just started doing it and it’s been really nice so far, when I get a chance and it’s stabilised a bit I’m going to tidy it up and share it. But there’s not much I’ve added beyond the above at the moment (just some bits to mix-in arrays, which was what set me off on this whole thing!)

I just have a static page that I randomly change - you can see mine here. In this case I was testing the idea of having text within an SVG for better scaling from mobile to desktop, and also I’m loving orange and purple at the moment for some reason! Oh, and I was testing automated deployments from CI/CD, so I always use my own base domain with those first tests!

Glad you sorted it though! It’s a nightmare when you get such an opaque error and there’s so many moving parts that could be responsible!

Assume nothing! Test every little assumption and you’ll find the problem. Some things to get you started:

• Does the “app” domain resolve to the app container’s IP from within the nginx container?
• Can you proxy_pass to the host:port directly rather than using an upstream definition? If not, what about IP:port?
• Can you connect to the app container from outside (if exposed)? What about from inside the nginx container? What about inside the app container?
• Is the http(s) connection to the server (demo.example.com) actually going to your nginx instance? Shut it down and see if it changes.
• If it works locally on 80, can you get it to work on the VPS on 80?
• Are you using the exact same docker-compose.yaml file for this as locally? If not, what’s different?
• Are you building the image? If so, are you incrementing the version number of the build so it gets updated?
• Is there a firewall running on the host OS? If so, is it somehow interfering? Disable it and see.

While not a direct solution to your problem, I no longer manually configure my reverse proxies at all now and use auto-configuring ones instead. The nginx-proxy image is great, along with it’s ACME companion image for automatic SSL cert generation with certbot - you’ll be up and running in under 30 mins. I used that for a long time and it was great.

I’ve since moved to using Traefik as it’s more flexible and offers more features, but it’s a bit more involved to configure (simple, but the additional flexibility means everything requires more config).

That way you just bring up your container and the reverse proxy pulls meta-data from it (e.g. host to map/certbot email) and off it goes.