[kwlug-disc] Docker on VPSes

[Ronald Barnes]

Benjamin Tompkins wrote on 2019-01-22 6:55 a.m.:

> To add to this, my understanding of containers of any type is that they 
> are best used for ephemeral work loads.

As I understand it, this is correct.

Also use containers when it's imperative that software version x.y is 
used, regardless if the OS running the application(s) upgrades to x.z.



> So for instance if you have a large web front end each session that 
> connects gets it's own container that is created on demand.  The client 
> does their thing and the contain then gets destroyed and goes away.  Any 
> and all data is loaded/saved through the container to a backing object 
> store/database/however the site is designed.  This helps to greatly 
> limit the footprint of the application.

I don't think this is correct (I stand to be corrected though).

Nor do I think that a new container for each session would limit the 
footprint; that just doesn't seem to make sense.


> For this case, you would likely break it into to two parts.  First is 
> the container that would have the Apache/nginx frontend with Drupal that 
> would then connect back to a database that is on (potentially) the 
> host.

This I agree with.  And in discussion with Tim, he recommended that the 
files / data be stored on the host OS, not inside the container.


>  Second, you would need some sort of load balancer

> So now the question becomes, do you want to manage all of that?


That's where a Docker Swarm shines.  Have various VPSs joined to the 
master in a "swarm" which can be increased in anticipation of impending 
increases of traffic.


Back to Paul's question - I don't know if using Docker would make your 
situation any better or easier, but since it's a cool technology that's 
rapidly growing in popularity, I say, "Why not?"



Any corrections welcome.

rb