Containers All The Way Down

Talk about building blocks of modern containers
(from chroot to AuFS). Introduction to Docker with Ruby+Redis
container examples, and docker-compose workflow.

Source code and more details: https://github.com/morhekil/talks-and-slides/tree/master/containers

Transcript

1. Containers all the way down
2. Containerisation is not virtualisation
3. Containers are not Hypervisors
4. Why virtualise? 60s-70s Big mainframes, time-sharing CP-65 for CP/CMS OS by IBM
5. Why virtualise? cheap x86 low infrastructure utilisation
6. Why virtualise? cheap x86 low infrastructure utilisation define low?
7. Why virtualise? VERY LOW infrastructure utilisation · 5% - McKinsey's Data Center study, 2008 · 8% - Accenture paper, 2011 · 12% - Gartner, 2012
8. How to virtualise? · Hypervisors · Containers
9. Hypervisors first mentioned in 1965, for IBM's system. · 1988 - first SoftPC for Macintosh; can only run DOS, later - Win 3.x, 9x · 1997 - Connectix VirtualPC for Macintosh, later sold to Microsoft
10. Hypervisors
11. Hypervisors
12. Hypervisors · 2001 - VMWare GSX Server, x86 Windows; Connectix VirtualPC for Windows · 2003 - Xen, open-source hypervisor · 2005 - free VMWare Player · 2006 - VMWare Server, free Microsoft VirtualPC · 2007 - VirtualBox Open Source Edition
13. Containers
14. Containers guest OS can only be of the same kind (e.g. Windows or Linux) as the host OS.
15. Containers 1982 - chroot (4.2BSD) filesystem only
16. chroot 4.4BSD-Lite - sys/kern/vfs_syscalls.c chroot(p, uap, retval) // ... { register struct filedesc *fdp = p->p_fd; int error; struct nameidata nd; if (error = suser(p->p_ucred, &p->p_acflag)) return (error); NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE, uap->path, p); if (error = change_dir(&nd, p)) return (error); if (fdp->fd_rdir != NULL) vrele(fdp->fd_rdir); fdp->fd_rdir = nd.ni_vp; return (0); }
17. chroot let's chroot something sudo chroot -u `whoami` newroot
18. · 1982 - chroot (4.2BSD) (filesystem view only) · 2000 - FreeBSD jail (fs + users, socket and process interaction restrictions) · 2001 - Linux-VServer (with a kernel patch) · 2005 - Solaris Zones (allow dedicated CPU, RAM, net-if controls, plus ZFS-powered features - snapshots and cloning) · 2005 - OpenVZ - by SWSoft, aka Parallels (with a kernel patch)
19. · 2008 - LXC · 2013 - lmctfy (Google's set of tools controlling cgroups) · 2013 - Docker (leverages Linux cgroups and namespaces - first via LXC, then libcontainer)
20. AuFS Advanced Multi Layered Unification Filesystem unite several directories (branches) into a single virtual filesystem
21. AuFS
22. AuFS sudo mount -t aufs -o br=~/work/dir01:~/work/dir02 none ~/view mount -o remount ~/view
23. Docker · LXC · AuFS · Application-centric · Toolset and ecosystem
24. Docker LXC namespaces and cgroups process isolation
25. Docker AuFS layered filesystem (versioning)
26. Docker Application-centric deploying applications, not servers
27. Docker Toolset and ecosystem · base images · public registry · standard containers · third-party tools and workflows
28. ClickME Application Two containers: · Ruby (trivial Sinatra app) · Redis
29. Docker on OSX boot2docker runs a vm on VirtualBOX, automatically installs/configures it
30. Docker on OSX boot2docker much better than it used to be, but sometimes still buggy
31. Docker on OSX boot2docker > brew install boot2docker > boot2docker help > boot2docker init > boot2docker start
32. Dockerfile container definition Reference just read it, it's a dozen of commands :)
33. Let's build a container!
34. Why? (Again)
35. Why? (Again) Repeatable infrastructure Containers + Registry
36. Why? (Again) Immutable infrastructure CoreOS
37. Why? (Again) Immutable infrastructure Also a challenge - no local state/storage!
38. Why? (Again) Immutable infrastructure Network everything · logs - syslogd/fluentd/logstash, · files - object storage (S3/Swift/Riak)
39. Why? (Again) Infrastructure as a code Dockerfile
40. Why? (Again) Easy preconfigured environments docker-compose
41. Why? (Again) Composable services docker-swarm, fleet
42. The cloud is coming!
43. References · A Dive into Docker · The Docker Ecosystem · The Docker Book · Docker in Practice