Short version, outside of a short tutorial to get Docker up and running, I really have not used it. I have read about it quite a bit, and see why it’s got very nice value. But, I have not really dived all in.
Here is my use case: I have 2-3 servers where I run many different web applications: email (postfix/dovecot/spamassassin/etc) + nextcloud + gitlab + a static home page + a little shopping list app) all with LE and behind Apache.
It has been up and running without significant issue for 2+ years.
The one problem with this setup is, it’s not very modular AT ALL. As time as gone on, I have become afraid of doing much to it, for fearing of breaking something. For example, slowly I am finding myself in a situation where I need to upgrade the database (couple year old version of mysql), but all the applications share the same one! This is bad design, I know. But, it was my first stab.
Now, that I feel a bit more mature, I see my errors.
Docker seems like it could help. I could basically put all these apps in their own containers, all behind a common web server that handles LE, and maybe (I will have to decide) a common DB or each with their own.
Also, should I ever want to, I could move these systems of my local home servers, onto a cloud server without major issue.
I guess I just gotta figure out (after I figure out Docker basics), how to manage the interaction between containers (if I share a db, probably will just eat the overhead, and not do that), and networking between the web host and the various containers. Then, I should be good to go.
Is my thinking sound? Should I take the leap?