footer: June 12, 2020 slidenumbers: true
Lunch and Learn series - remote edition
Nick Brandaleone AWS Specialist SA - Containers
- Ask questions
- Try to be on mute when not asking questions
- I will be moving quickly
- https://github.com/nbrandaleone/what-is-a-container
- I will be using Cloud-9 (Ubuntu OS) for a demo
| Lesson | Time |
|---|---|
| Why are containers so popular? | 5 minutes |
| What is the magic? | 5 minutes |
| Demo, using BASH | 20 minutes |
| Firecracker demo | 5 minutes |
- Code portability issue is solved
- Faster start-up time makes them preferrable to VMs
- Greater hardware efficiency makes them cheaper
- Isolation provides security (not perfect though)
- Docker tooling is easy to use
- Namespaces
- cgroups (Linux capabilities + Seccomp)
- COW or layered filesystem
Linux Kernel tricks - Windows should use .Net Core
CGROUP - limit cpu/memory for a group of processes. MNT: It allows a process to have its own filesystem. PID: The pid namespace gives a process its own view of /proc. NET: Isolated network stack. UTS: System’s hostname and domain name. USER: The user namespace maps the uids to different uids. IPC: message queues and shared memory.
Where namespaces isolate a process, cgroups enforce fair resource sharing between processes.
For example:
- how much memory a process can use
- how much CPU can a process use
- how many children processes can be spawned
-
Layered Filesystems are how we can efficiently move whole machine images around.
-
Also known as tarballs...
-
Storage Drivers:
- overlay2
- aufs (older version)
- Docker -> the company that made it easy to use containers. Purchased by Mirantis in late 2019.
- OCI -> The open source components of Docker
- containerd (high-level interface)
- runc (low level)
No fork() and exec()
We now clone() or unshare()
Stay Safe and Sane
- https://www.infoq.com/articles/build-a-container-golang/
- https://gist.github.com/christophberger/58505418133d474486a88f958d8ea14b
- https://www.nickaws.net/linux/2020/03/05/Containers-are-not-magic.html
- https://www.youtube.com/watch?time_continue=2&v=sK5i-N34im8
- https://www.youtube.com/watch?v=Utf-A4rODH8
- https://containersummit.io/events/nyc-2016/videos/building-containers-in-pure-bash-and-c
- http://redhatgov.io/workshops/containers_the_hard_way/
- https://ericchiang.github.io/post/containers-from-scratch/
- https://github.com/riyazdf/dockercon-workshop