Meetup - Red Hat - Techtalks Copenhagen What are containers, how do they work. and some details about RHEL Atomic http://www.meetup.com/Red-Hat-Tech-Talks-DK/

1. Containers
Hosts and lxc, docker..
@RedHatNordics
@sshaaf

2. Containment , always been ...
Zones
LXC

3. Namespaces
namespace wraps a particular global system
resource in an abstraction that tells the
processes within the namespace that they have
their own isolated instance of the global
resource

4. Namespaces
Mount - CLONE_NEWNS, Linux 2.4.19
IPC - CLONE_NEWIPC, Linux 2.6.19
PID - CLONE_NEWPID, Linux 2.6.24
UTS - CLONE_NEWUTS, Linux 2.6.19
Network - CLONE_NEWNET, started in Linux 2.6.24
User - CLONE_NEWUSER, started in Linux 2.6.23

5. Cgroups
Control Groups provide a mechanism for
aggregating/partitioning sets of
tasks, and all their future children, into
hierarchical groups with
specialized behaviour.
Ref: Kernel.org

6. Cgroups
Subsystems, hierarchies.
Parameters: Memory, disk, cpu ..
CPU Set
Mem
CPU
Top Set

7. I got containerized

8. Software packaging concept that typically includes an application and all of its runtime
dependencies.
● Easy to deploy and portable
across host systems
● Isolates applications on a
host operating system. In RHEL,
this is done through:
● Control Groups (cgroups)
● kernel namespaces
● SELinux, sVirt
What is?

9. Loose 1 not all
...and compromised, there is far less exposure.
Only the container process is lost – lose the
process not the system.

10. Overview

11. Containers in RHEL

12. Image based containers

13. Virt and containers