Show HN: Bocker – Docker implemented in 100 lines of bash

Post by maccam94 » Wed, Jul 22, 2015, 7:09 AM UTC

p8952 wrote: post #11

vezzy-fnord wrote: post #3

Using btrfs subvolumes as the image format, that's a nice touch. On the same road as the hypothetical systemd packaging system (not that I'm very enthusiastic about that). The network, PID and mount namespaces are the ones unshared, plus a private /proc. I like tools like this because they're reality checks on how the basics of Linux containers are just a few essential system calls, and particularly that they're limi…

Thank you. One of the things I found really interesting here is how much could be done with just basic userland tools, and how old some of those tools are. Docker was released in 2013, but support for kernel namespacing has been around since ~2007. That's quite a long time for such a great feature to go mainstream.

Post by arianvanp » Wed, Jul 22, 2015, 7:17 AM UTC

Post by vidarh » Wed, Jul 22, 2015, 7:45 AM UTC

hueving wrote: post #58

ecnahc515 wrote: post #32

Earlier quoted context omitted.

It turns out that the kernel is smart enough to deduplicate (in memory) the same version of a shared library across VM boundaries, so I don't really see why we need to make packaging handle this, especially if this can be applied to containers (if it isn't already). Duplicates of the same file on disk is not a big deal, and can be solved by a good file system which handles deduplication. I don't see why we necessaril…

This means your security depends on the app maintainer, which is a terrible place to be in. I don't want to have to wait for the latest image of 100 apps and hope they didn't break anything else just to deal with an openssl vulnerability.

Post by vidarh » Wed, Jul 22, 2015, 7:53 AM UTC

Spivak wrote: post #57

pekk wrote: post #54

Earlier quoted context omitted.

No, that's a dumb joke. Actually I don't really even use Docker personally. HN's standard middlebrow dismissal of Docker is to claim that it's nothing except LXC, which really misses the point entirely. But at least it lets people pretend they are smarter, which is what really counts.

They are rightfully dismissive of Docker because it's just the current cycle of trendy abstractions. It's a barely passable solution to a bigger problem. "We're running many services on a single machine. But this is complicated and difficult to update and maintain." "We took our machine, ran a virtualization platform on it, and split each service into its own VM. But this comes at the cost of increased resource usage…

Post by merb » Wed, Jul 22, 2015, 8:37 AM UTC

davexunit wrote: post #31

catern wrote: post #28

Earlier quoted context omitted.

Perhaps the parent poster was wryly indicating that he doesn't think that much of Docker. Certainly I think both of you are correct: Docker is about packaging, and it absolutely sucks at that. The only reason that that is not obvious is that Docker is piggybacking on the relatively excellent and well-developed package management of distributions like Debian and Fedora.

Debian and Fedora do packaging better than Docker, relatively speaking, but they still have major issues that have lead to "solutions" like Docker, Chef/Omnibus, etc. They install packages globally which doesn't allow for having multiple versions of the same software/library, they don't allow for unprivileged package management so users are at the mercy of the sysadmin, there's no transactional upgrades and rollbacks…