mvallim/kubernetes-under-the-hood

This tutorial is someone planning to install a Kubernetes cluster and wants to understand how everything fits together.

Kubernetes under the hood

It even includes a SlideShare explaining the reasoning behid it Kubernetes under the hood journey

Target Audience

The target audience for this tutorial is someone planning to install a Kubernetes cluster and wants to understand how everything fits together.

Index

Atention: the documentation for this project is being actively improved to explain the demonstrated concepts clearly. If you face any difficulties while following the steps described in the documentation, please open an issue, so we can keep improving it. The version of Kubernetes used here is 1.20.15

1. Introdution
   • Up and running out of the cloud
2. Planning
   • Architecture Overview
   • Technology Stack
   • Networking
3. Kubernetes
   • Overview
   • Masters and Workers
   • etcd
   • flannel
   • Linux image
4. Putting all together
   1. How to setup the Debian Linux image from scratch
   2. How to setup the Gateway and Busybox components
   3. How to setup the HAProxy Cluster with high availability
   4. How to setup the Masters using kubeadm bootstrap
   5. How to setup the Workers using kubeadm bootstrap
   6. How to setup the Dashboard
   7. Demo Application
   8. LoadBalancer
      1. How to setup the MetalLB
5. Appendix
   1. External CA Infrastructure
      1. How to create the external CA Infrastructure
   2. External etcd
      1. How to setup the external etcd with TLS
      2. How to setup the Masters using kubeadm bootstrap with external etcd

Contributing

Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.

Versioning

We use GitHub for versioning. For the versions available, see the tags on this repository.

Authors

• Marcos Vallim - Initial work, Development, Test, Documentation - mvallim
• Fabio Franco Uechi - Validation demo - fabito
• Dirceu Alves Silva - Validation demo - dirceusilva
• Leandro Nunes Fantinatto - Validation demo - lnfnunes
• Ivam dos Santos Luz - Validation demo, Articles - ivamluz
• Marcos de Lima Goncalves - Validation demo, Presentation Organizer - marcoslimagon
• Murilo Woigt Miranda - Validation demo, Presentation Organizer - woigt-ciandt

See also the list of contributors who participated in this project.

License

This project is licensed under the BSD License - see the LICENSE file for details

kubernetes-under-the-hood's Issues

Typo

Hello,

It seems https://github.com/mvallim/kubernetes-under-the-hood/blob/master/documentation/ca-external-infrastructure.md?plain=1#L344 should be:

Create the intermediate `ca-certificate-manager` CA certificate chain

Since etcd-ca is already created at point 9.

Robin,

Unable to access Demo Application Website from Host Computer

Hi Team,

I have been working my way through your Kubernetes under the hood project in order to deploy a small production Kubernetes server at work for use by our development team.

I have been able to deploy and setup all of the masters/nodes using your instructions as well as launch the demo application. However I am running into an issue with accessing the website service once deployed. The project says to go to http://kube-node01.kube.demo:{NodePort} however when i try to do this I get a server not found error.

Also when i try to nslookup kube-node01 from the host computer I am unable to find the ip address assigned so think potentially I am missing a IP route on the host to get to the DNS/node network? When ssh'd into the busybox I am able to nslookup kube-node01 succesfully and also curl the website and get the correct response.

Any help on trying to work out what is going wrong here would be much appreciated. I believe I have followed all the documentation correctly to this stage but may have missed something.

Thanks for you help,
Callum

"Demo the application " is broken

https://github.com/mvallim/kubernetes-under-the-hood/blob/master/documentation/kube-demo-application.md#creating-the-guestbook-frontend-deployment

The container gbfrontend:v4/v5 does not exist. Looks v4 or v5 tag was removed from Google Container Registry and the application was broken.

The source code is: https://github.com/kubernetes/examples/blob/master/guestbook/frontend-deployment.yaml#L19

The better way is using private registry and set contained.

Kubernetes Network Model

Just a small doubt about the Kubernetes Network Model picture in Flannel documentation

the picture show that pod interface numbered "eth1", "eth2" and "eth3" which is not correct,
as i far as i know, pods always hold "eth0" as an interface

e.g. create new pods on the same node
pod-1

pod-2

i know this maybe not a mistake and just used as illustration

How to setup storage GlusterFS

Hi guys, thanks for your great work, it's really helpful. I just have a small question on the documentation on the set up storage GlusterFS. In the section "Send commands to all panes", step 1, "join the Gluster nodes to the cluster", i saw the command is "ssh kube-node01", which mean it's issued from kube-node01(worker node I assume), but I think this should be issued from the newly created glusterFS node? Please correct me if I am wrong, thanks.

Question about : etcd documentation

Hello,

I am learning about etcd and TLS and found your repo but I am stuck. Found a solution using cfssl but I want to use openssl directly. Nor peer or server extensions are available and I can't find the config.conf file you are using.

Could you share it or point me where I can find it ?

Robin,

documenation required to enable metallab in virtualbox

I want to build metal-lb load balancer with a range of IP address to assign for mariadb deployment using helm.

I've following 3 Kubernetes nodes and a jump server -
On each of those VMs I've 2 adapters

1. NAT network
   K8s Network - 10.0.2.0/24
2. Vboxnet0

#############################################################################
root@control-plane:/home/vboxuser# ifconfig | grep inet | grep -v inet6
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
inet 10.0.2.4 netmask 255.255.255.0 broadcast 10.0.2.255
inet 192.168.56.102 netmask 255.255.255.0 broadcast 192.168.56.255
inet 127.0.0.1 netmask 255.0.0.0
inet 10.10.235.128 netmask 255.255.255.255 broadcast 0.0.0.0
root@control-plane:/home/vboxuser#
#############################################################################
vboxuser@work-node1:$ ifconfig | grep inet | grep -v inet6
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
inet 10.0.2.5 netmask 255.255.255.0 broadcast 10.0.2.255
inet 192.168.56.103 netmask 255.255.255.0 broadcast 192.168.56.255
inet 127.0.0.1 netmask 255.0.0.0
inet 10.10.64.0 netmask 255.255.255.255 broadcast 0.0.0.0
vboxuser@work-node1:$
#############################################################################
root@work-node2:/home/vboxuser# ifconfig | grep inet | grep -v inet6
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
inet 10.0.2.6 netmask 255.255.255.0 broadcast 10.0.2.255
inet 192.168.56.104 netmask 255.255.255.0 broadcast 192.168.56.255
inet 127.0.0.1 netmask 255.0.0.0
inet 10.10.181.128 netmask 255.255.255.255 broadcast 0.0.0.0
root@work-node2:/home/vboxuser#
#############################################################################
root@jump-server:/home/vboxuser# ifconfig | grep inet | grep -v inet6
inet 10.0.2.7 netmask 255.255.255.0 broadcast 10.0.2.255
inet 192.168.56.105 netmask 255.255.255.0 broadcast 192.168.56.255
inet 127.0.0.1 netmask 255.0.0.0
root@jump-server:/home/vboxuser#
#############################################################################

Based on your documentation - https://mvallim.github.io/kubernetes-under-the-hood/documentation/kube-metallb.html

how to configure the local routing ?
what should be routes and bit explanation.