kjx-headless // WIP

POC for a custom headless LFS distro setup, deploy and monitoring

Taking up from where eulab-poc left ;D

This proof-of-concept monorepo gathers concepts from several [1] constrained systems to create a *NIX Distro, Linux-based. Composed by Busybox/LFS, it applies CI/CD for infrastructure automation. Aimed to explore the performance of virtualized environments.

Check the Gitlab mirror for an example using Jenkins instead of Github Actions.

sh .-"``"-. / _.-` (_) `-._ \ (_.----._) / \ / \ / `\ \____/ /` `-.____.-` __ _ / \ / /__ (_)_ __ / \ / '_/ / /\ \ / /_ | | _\ /_/\_\_/ //_\_\ | | | |___/ deomorxsy/kjx |__|__| ---------------------------------------------- /_ | _\ Reboot (01.00.0, ${GIT_CONTAINERFILE_HASH}) ----------------------------------------------

The entire boot flowchart, from kernel init scripts to k3s initialization: kernel | 1| .--- /etc/runit/reboot ---. 14 ,---| 2 |<--- (runit-init) <---- init 0|6 | '--- /etc/runit/stopit ---' | | 13 | '------------------------------------> 3| .-----> runit | | | | .---<---------<----+-------->---------. | | | | 4| | 6| 10| runit/1 | runit/2 runit/3 | | | | 5| | 7| 11| start things | runsvdir sv | | | | | | 8| | +---------------+ '--->---'| runsv /var/service/* | Parent Process| | | | +---------------+<------------' | | | | 12| |1. Fork libbpf | stop things |2. Fork k3s process | | | | | |3. Send signal SIGUSR1 to libbpf | send SIGTERM v v v +--------------------+ +--------------------+ | | Child: libbpf | | Child: k3s Process |---' | Program | | Wait for SIGUSR2 | +--------------------+ +--------------------+ ^ ^ | 4. Wait for SIGUSR1 | 6. Wait for SIGUSR2 | (self-loop) | (self-loop) v v +--------------------+ +--------------------+ | Start Monitoring |------------>| Signal: Monitoring | +--------------------+ | Started | | +--------------------+ | | | | | 5. Send SIGUSR2 to k3s Process | v v +--------------------+ +--------------------+ | Monitoring Active | | Start k3s Process | +--------------------+ +--------------------+ | ┌──────────────────────┘ | │ | ┌─────────────── ▼ ───────────────────┐ v │ ┌──────────────┐ │ +--------│-------│server process│------------+ │ | ▼ └──────────────┘ | │ | +----------+ | │ | |supervisor|──┐ +-------+ ◄───────┐ | │ ┌──────────────┐ | +----------+ │ |flannel|--------┐| | │ +------│client process│----+ | ▼ +-------+ || | │ | └──────────────┘ | | +----+ +----------+ || | │ | +-------+ | | |kine|◄───|API-server| ◄-┐ +----------+ || | │ | |flannel|──────┐ | | +----+ +----------+ └-|kube-proxy|◄┘| | │ | +-------+ ▼ | | ▲ ▲ ▲ +----------+ | | │ | ▲ +----------+| | +----------+ │ │ │ | | │ | +------+ | |kube-proxy|| | |controller| | | | +-------+ | | │ | |tunnel| └─┐ +----------+| | |manager |──┘ | └──────|kubelet|─────┘ | └───|proxy |◄┐ | | | +----------+ +---------+ +-------+ | | +------+ | └─────┐ | +---------------|scheduler|-----│------------+ | ▲ └────┐ | | +---------+ │ | └───── +-------+ | │ +-------------|kubelet|----+ +----------+ │ +-------+ |containerd| ◄───────┘ +----------+ │ +----------+ |containerd|◄───────┘ │ +----------+ │ +---+ │ └─► |Pod| │ +---+ +---+ └─► |Pod| +---+

Unit and Integration tests use the go testing package with code coverage. Currently exploring fuzz tests. There is also a chore using bats-core. The adopted strategy is composed by spinning up a container, setting permissions with libcap and switching between test scopes for different containerized environments.

References

[1] LFS, Sabotage, Alpine, Busybox OS, ALFS, PILFS, Cross Linux from Scratch, Embedded Linux from Scratch, Dragora Linux, Alpine Linux and Void Linux.

• Alpine Wiki
• Sabotage && devsonacid
• Buildroot manual
• ALFS
• Cross Linux from Scratch
• Embedded Linux from Scratch
• Dragora Linux Handbook || archive
• VoidLinux docs
• Alpine User Handbook
• TinyEmu
• Hardened Gentoo
• Linux From Scratch on the Raspberry Pi
• runit-for-lfs
• containerd-rootless
• rootless containers initiative
• rhatdan's Podman in Action
• qemu-fuse-disk-export script
• youki tests!
• the cromwell runntime
• The firecracker scripts from kubefire