docs VS tini

I will recommend you review the documentation for the official Postgresql docker images which you can read here.

This is the full documentation for these images. Please note, this page has links to Docker official documents on volumes, etc., which are necessary to run images such as this.

We've just followed the official documentation to add a PostgreSQL database server. This will act as an application container, as our app will soon be depended on it. And in order to make sure that the database container is always started whenever we start our application container, we've added a new depends_on key to the app service and let it know which other service(s) it, well, depends on. This will make sure that the database server is up and running before the app. You may also have noticed that we've mounted volume to our database server's datapath a bit differently. This is known as "named volume". We'll discuss it a bit more in another part, it's not relevant to what we're learning here.

Nextcloud isn't hard to setup, follow the official doc https://github.com/docker-library/docs/blob/master/nextcloud/README.md

Looking at the setup for this (link here: https://github.com/docker-library/docs/blob/master/nextcloud/README.md), I am starting to understand a lot of the recent posts that we've seen & how much of a mess it still is :(

Coming back to nextcloud, the official readme of the nextcloud image has a few notes on how to set up both nextcloud versions.

Use the native command envstubst to replace the Auth Tokens in your Config File before starting NGINX. Example: https://github.com/docker-library/docs/tree/master/nginx#using-environment-variables-in-nginx-configuration-new-in-119

It's not clear why you want to split the web server (nginx) and the app (nextcloud). However, if you do have a good reason, you're in luck, they have a compose file that does just that: https://github.com/docker-library/docs/blob/master/nextcloud/README.md#base-version---fpm (version 2, but it'll work)

yes busybox httpd or civetweb is even smaller, both around 300kb.

for tini you mean https://github.com/krallin/tini? how large is your final docker image, why not just alpine in that case which is musl+busybox

Tini, a useful process manager for containerized apps

Ah gotcha. I believe it can be baked into images as well, per the entrypoint example in the readme: https://github.com/krallin/tini

Not sure how this will fare IRL in k8s as I haven’t much experience there. It’s still silly that this is the default behavior where you need something like Tini, but I digress.

To be fair, even for running a single process the pitfalls are real. I've been seeing Tini[1] a lot for these situations.

I just read in the README that Tini is included by Docker since 1.13 if using --init flag.

[1] https://github.com/krallin/tini

The default init process used is the first docker-init executable found in the system path of the Docker daemon process. This docker-init binary, included in the default installation, is backed by tini.

AFAIK It's for the init process to reparent zombie processes. See TINI

The second easiest (and most common when your entry point is a bash script) is to use a fake init tool like tini