Introduction to containers

About Me

  • I am Mohammed Daoudi AKA iduoad
  • I am a devops engineer @Nimbleways
  • I am programming enthusiasts (Go/Python)
  • I taught a semester of Database Security @Sorbone university Paris
  • I love cinema

What are containers ?

A little bit about container history

1979-90s: The inception

  • It is all about process isolation.
  • 1979: Unix V7 introduced chroot.
    • chroot segregates file access for unix processes.
  • 1982: BDS introduced chroot.
  • 2000: FreeBSD introduced jails.

90s-00s: The downfall of container

  • Windows is here !!
    • Windows is not compatible with UNIX.
    • We need to run Windows on Unixes, and the other way too.
    • The rise of hardware virtualization.
  • Hardware virtualization is about machines (CPU, RAM, Devices, …)
  • Virtual machines have nothing to do with containers.

early 00s: Renaissance - The age of VPS

  • The web is hot = High demand for web hosting !!
  • Better resource management + process isolation vs Security + true isolation.
  • 2001: Linux VServer
  • 2004: Solaris Containers
  • 2005: Open VZ (Open Virtuzzo)

2008: Finally Linux container - LXC

  • 2006: Google contributed Cgroups into the linux kernel.
  • 2008: LXC is here: the first complete implementation of a linux container manager.
    • LXC is a system container manager.
    • Introduced container images.
    • LXC is Linux native.

2013: DOCKER !!

  • 2011-2013: Warden, LMCTFY, …
  • 2013: Docker is here
    • Docker started as a PAAS company (like heroku).
    • Docker used LXC as a backend, then moved to libcontainers after.
    • Docker solves a new problem.

2015-: The golden age of cloud native

  • 2015: Open Container Initiative
  • 2015: Kubernetes
  • 2015: Cloud Native Compute Foundation
  • 2015-: Tons of container engines, runtimes and tools: podman, buildah, skopeo, crun, gVisor, katacontainers…

Linux containers under the hood

Linux processes

linux process table

Linux Namespaces.

Namespaces are a feature of the Linux kernel that partitions kernel resources such that one set of processes sees one set of resources while another set of processes sees a different set of resources.

int clone(int (*fn)(void *), void *stack, int flags, void *arg, ...
                 /* pid_t *parent_tid, void *tls, pid_t *child_tid */ );
int unshare(int flags);
int setns(int fd, int nstype);

Linux Namespaces

Linux Namespaces

Linux Namespaces.

  • PID namespaces
  • UTS namespaces
  • Mount namespaces
  • Network namespaces
  • User namespaces
  • IPC, Date

Linux Namespaces.

Linux Namespaces


cgroups is a Linux kernel feature that limits, accounts for, and isolates the resource usage of a collection of processes.


  • Linux Capabalities
  • Seccomp
  • SeLinux/AppArmor

Running containers

Container lifecycle

Running Containers

Case Studies


Docker runtime

PBS (container-tools)


System container runtimes: LXC/LXD, OpenVZ …


Thank you

Let’s be friends! 🤗