1. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
Create your containers with PerlCreate your containers with Perl

2. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
So first... Who am I?So first... Who am I?

3. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
So first... Who am I?So first... Who am I?
➢ System Administrator at heartSystem Administrator at heart
➢ Teaching at Sofia UniversityTeaching at Sofia University
➢ Organizing events like this one...Organizing events like this one...
➢ CEO of 1H Ltd.CEO of 1H Ltd.
➢ CTO of GetClouderCTO of GetClouder
➢ Chief architect of Siteground.comChief architect of Siteground.com

4. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
The current state of containers
➢ LXC
➢ Docker
➢ lmctfy
➢ A bunch of other small implementations
➢ Build it your self

5. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
Root inside the containerRoot inside the container
ONLY WITH LXCONLY WITH LXC

6. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
So why would you need a Perl
implementation
➢ Patching LXC is writing in C...
➢ Writing in C is not very user friendly
➢ If most of your logic is already in Perl...
➢ Keep less moving blocks in your architecture

7. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
So what the hell is a container?
➢ chroot ( isolate the directory tree )
➢ unshare ( create new namespace(s) )
➢ cgroups ( add limits )
➢ drop capabilities (optional)

8. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
What do we have in Perl?
➢ Linux::Unshare
➢ Linux::Setns

9. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
What do we need?
➢ Linux::Capabilities
➢ Linux::Networking

10. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
What am I proposing?
a toolkit
➢ pc-start
➢ pc-stop
➢ pc-restart
➢ pc-list
➢ pc-top
➢ pc-attach

11. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
➢ pre-read-config hook
➢ read yaml config
➢ post-read-config
➢ prepare cgroup
➢ post-cgroup-setup hook
➢ fork
➢ prepare mount hook
➢ chroot
➢ post-chroot hook
➢ unshare
➢ post-unshare hook
➢ drop caps
➢ post-dropcaps hook
➢ setup networking
➢ post-networking hook
➢ fork -> exec init
➢ post init hook
➢ setup user mappings
➢ post usermap hook
So let'sSo let's
look inside thelook inside the
implementationimplementation
in depthin depth
pc-startpc-start

12. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
➢ pre-read-config hook
➢ read yaml config
➢ post-read-config
➢ check if there is a cgroup
➢ check if the cgroup is not empty
➢ check if the base device
➢ find a FD from one of the PIDs
➢ pre-attach hook
➢ setns
➢ execute bash -i
pc-attachpc-attach

13. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
➢ pre-read-config hook
➢ read yaml config
➢ post-read-config
➢ check if there is a cgroup
➢ check if the cgroup is empty
➢ do pc-attach
➢ execute halt
pc-stoppc-stop

14. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
➢ loop trough the configs
➢ check if the cgroup exists
➢ check if the cgroup is empty
➢ check if it has init running inside
pc-listpc-list

15. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
➢ Loop trough all the configs
➢ check if the cgroup exists
➢ check if the cgroup is not empty
➢ collect the following stats
➢ cpu usage
➢ memory usage
➢ I/O usage
➢ Network usage
➢ It should allow the admin to
➢ sort each by each resource
➢ handle signals
➢ configure the interface
pc-toppc-top

16. YAPC::EU 2014 SofiaYAPC::EU 2014 Sofia
http://github.com/hackman/azilian