Rich Freeman on 7 Nov 2017 08:50:52 -0800

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Re: [PLUG] small business server virtualization?

On Tue, Nov 7, 2017 at 8:14 AM, Lee H. Marzke <> wrote:
> Again as I understand it , proper containerization is separating an application
> into it's components, so you wind up with many more components than VM's.

I'd argue that this is proper hosting, and not proper
containerization, but since containers are cheap you see it more

> A developer that wants to use the latest release of some library for instance,  can't
> do that on an LTS release of Ubuntu provided by IT, but in a container he can put together
> his small application, custom lib, etc and now run it.   IT now has to deal with a huge
> number of variants of the same lib in production, not to mention that this lib might be only an
> alpha release, and some how the production app is now failing, or has security
> issues because of vulnerabilities in that lib.   IT operations cares about different
> things that developers.   So developers start using more versions of libraries,
> and perhaps less stable.

So, custom libraries and containers are orthogonal issues.

You can tell your developers to stick to the Ubuntu LTS and run it all
in a container.  Heck, Ubuntu even publishes Docker images for this

You can also let your developers deploy whatever library versions they
want on your VMs or physical hosts.  It will cost you all the hassles
you bring up, but you can do that.

The image management in Docker makes it easier to add layers with
things like different library versions.  Separating all your services
of course also helps because your custom library only impacts one
service and not 47 of them.

However, the fact that Docker makes it easier doesn't mean that it
will ever be as easy as just telling everybody to stick to Ubuntu LTS,
and you can certainly still do that.  Sticking only to the distro libs
is obviously going to come with some drawbacks, but you can do it just
as easily with containers.

I wouldn't equate containers with
have-developers-run-production-servers.  It can make that approach
easier, but it certainly doesn't necessitate it.

I think the fact that containers are popular in the whole devops crowd
has led to a bit of conflation.  Containers are just a way to isolate
processes, nothing more or less. Anything else is an application of
the technology.  And Docker does WAY more than just containers.

If you can stick to Ubuntu LTS in a VM you can stick to it in a
container.  It is just a root filesystem.

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