Re: [Userops] Why is it hard to move from one machine to another? An analysis.

[Christopher Allan Webber]

Asheesh Laroia writes:

> Semi-sorry to be a pedant, but:
>
> On Wed, Apr 8, 2015 at 11:04 AM, Christopher Allan Webber <
> address@hidden> wrote:
>
>> Dave Crossland writes:
>>
>> > On 8 April 2015 at 11:22, Christopher Allan Webber <
>> address@hidden>
>> > wrote:
>> >
>> >> running 80 heavy and expensive Docker images
>> >
>> >
>> > Huh? The entire purpose of contains is that they are light and cheap.
>>
>> Are they?  Certainly compared to a VM as in terms of execution, they are
>> a lot smaller.  As in terms of size of the image itself, they seem to
>> often be just as large:
>>
>>
>> http://stackoverflow.com/questions/24394243/why-are-docker-container-images-so-large
>>
>> Astute Docker fans may point out that new images can be based off of a
>> lightweight image, and at that point your image is essentially a diff,
>> which is true!  Unfortunately, I don't think it remains that way
>> usually.  You need to upgrade packages on your derived image, and this
>> means either you need to migrate away from the base image, or maybe the
>> *base image* upgrades something, but regardless now you're out of sync.
>>
>
> If you're going to say that "Docker containers" are typically large and
> heavy-weight, that's a pretty reasonable thing to say!
>
> I emphasize this because I made a Sandstorm package (aka container image)
> of a Python hello-world using Pyramid a few weeks ago, and the app
> (including all its dependencies for the container) is a 5.1MB SPK file. So
> I just think it's important to keep the terminology clear so that people
> don't think that "container" _means_ large disk footprint, but rather that
> "Docker container" means large disk footprint.

This is a good point, and yes, I was basing it off of experiences with
Docker.

> Also, I generally agree with everything else you said; thanks for running
> virtual-asheesh-laroia on your email before sending. (-;

Good to the diffs between our analysis is not too large, yes! ;)

> As for reproducible images -- Sandstorm is getting there, but hasn't
> succeeded at that yet. It's on the queue, but we're not working on it
> super-duper-much at the moment.

Great to hear it's in the pipeline!  I do think reproducibility across
the entire stack is critical both from a user freedom perspective and
also for a practicality standpoint.