Show HN: Bocker – Docker implemented in 100 lines of bash • Hacker News Board

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

#1

Post by p8952 » Tue, Jul 21, 2015, 9:20 PM UTC

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

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

#2

Post by WD-42 » Tue, Jul 21, 2015, 10:08 PM UTC

Nice work. Great to see the advanced features of BTRFS put to use.

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

#3

Post by vezzy-fnord » Tue, Jul 21, 2015, 10:11 PM UTC

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 limited.

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

#4

Post by sandGorgon » Tue, Jul 21, 2015, 10:21 PM UTC

not sure if you ever saw this - https://www.phoronix.com/scan.php?page=news_item&px=CoreOS-B...

it might be interesting to see a version of your script using overlayfs

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

#5

Post by tlrobinson » Tue, Jul 21, 2015, 10:27 PM UTC

Here's a proof-of-concept implementation of "docker pull" in bash (YMMV, I think it has broken since I wrote it): https://gist.github.com/tlrobinson/c85dca269f4405ad4201

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

#6

Post by Bocker » Tue, Jul 21, 2015, 10:50 PM UTC

Approved.

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

#7

Post by p8952 » Tue, Jul 21, 2015, 10:58 PM UTC

sandGorgon wrote: post #4

not sure if you ever saw this - https://www.phoronix.com/scan.php?page=news_item&px=CoreOS-B... it might be interesting to see a version of your script using overlayfs

Interesting, it was my understanding that Docker was going in the other direction. Moving off AuFS towards Btrfs due to issues getting AuFS patches into the mainline kernel.

I'll have to look info CoreOS's reasons for going with Ext4.

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

#8

Post by p8952 » Tue, Jul 21, 2015, 11:00 PM UTC

WD-42 wrote: post #2

Nice work. Great to see the advanced features of BTRFS put to use.

Thank you.

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

#9

Post by zobzu » Tue, Jul 21, 2015, 11:02 PM UTC

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…

also that they dont use a root daemon and random hard to debug, hard to verify things.

it feels like most of them build large products around things to justify making money, while i like the simple, elegant, easy to verify little pieces of software (some call it "the unix way")

unshare and iproute are pretty decent for ex.

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

#10

Post by asdfaoeu » Tue, Jul 21, 2015, 11:02 PM UTC

There's also https://github.com/docker/dockerlite . But not sure how current it is.