Freya: Freya moved page Minutes 2026-01-23 to Minutes 2026-01-22: put it under the wrong name

2026-01-23T18:42:47Z

Freya moved page Minutes 2026-01-23 to Minutes 2026-01-22: put it under the wrong name

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Revision as of 18:42, 23 January 2026

Freya: Created page with "=Meeting Minutes 01/22/26= * Scott Raiford presenting on how to use Kubernetes * A little banter about the meeting and how LUG runs :P ==Scott Story:== * At a job lost a guy who knew a lot of stuff. There's a system they have to shut down everything and bring it back up 15 minutes later. * Next guy comes in to see how the code worked. The code is full of message boxes that say "I am here" and then SEGFAULTS. * There was no timing to the script, he conned the..."

2026-01-23T18:41:55Z

Created page with "=Meeting Minutes 01/22/26= * Scott Raiford presenting on how to use Kubernetes * A little banter about the meeting and how LUG runs :P ==Scott Story:== * At a job lost a guy who knew a lot of stuff. There's a system they have to shut down everything and bring it back up 15 minutes later. * Next guy comes in to see how the code worked. The code is full of message boxes that say "I am here" and then SEGFAULTS. * There was no timing to the script, he conned the..."

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=Meeting Minutes 01/22/26=

* Scott Raiford presenting on how to use Kubernetes
* A little banter about the meeting and how LUG runs :P

==Scott Story:==

* At a job lost a guy who knew a lot of stuff. There's a system they have to shut down everything and bring it back up 15 minutes later.
* Next guy comes in to see how the code worked. The code is full of message boxes that say "I am here" and then SEGFAULTS.
* There was no timing to the script, he conned the company into paying him :P

==The Presentation:==

* Kubernetes allows the hosting of a lot of software on very small amounts of hardware
** Uses containers very efficiently to make this work
* Linux has the kernel, then on top of that the userspace, and on top of that your own programs.
** Userspace is where your programs live.
** Userspace asks the kernel to do things like file access or sending packets.
** Userspace programs will ask the kernel about network adapters or other processes on the system
* A container is a namespace for processes
** If the kernel is asked what processes are running, it lies and says only the namespace's programs are running
** Multiple namespaces are possible
** Keeps applications from interfering with each other
* Kubernetes is solving the problem of managing containers in a scalable manner
** Example:
**# 3 nodes in a cloud
**# nginx is running on node 1, gateway on nodes 2 and 3
**# node 1 dies
**# nginx is moved into another node
**# when that other node dies, nginx is moved again This is what Kubernetes does, allowing things to keep running even if hardware fails.
** apiserver knows we need some state (a set of software that should be running), and if there's a mismatch, it changes things to make things the way they should be.
*** apiserver and its database is redundant so it is resilient
** istio: routes traffic based on hostname, etc.
** Controllers can be deployed as pods. apiserver itself is a container
** Working example:
*** Containerfile defines what is in the container, what is installed, what is exposed, etc
*** Trivia game needs to be run on a node, with a service that passes traffic into it
*** Write YAML to describe how to actually run the software, pass in traffic
**** Push YAML to apiserver, which then gets added to etcd and run by Kubernetes
*** YAML states how many copies of a software should run
*** Controller configures things to keep things running according to spec, can have side effects.
*** If any node in the cluster gets traffic on any port, it is forwarded through a virtual network to the trivia app
*** a change in the config will trigger a rebuild of the pods (clusters of containers)
*** ''several minutes of troubleshooting have been omitted from these minutes''
*** _19<span id="-54_"></span><span id="54_" class="tag">54_</span> IT WORKS!!

==Extra Little Notes==

* Each control node runs an apiserver
* There is a kubernetes service, anything that wants to make a request can ask it and it will be load-balanced to one of the apiservers
* Meant to fail: if one node goes down, others can pick up the slack
* Outside of Kubernetes, you can run a few instances of software like HAproxy so that when one dies you still have load-balancing.
* Kubernetes will constantly try and repair the cluster if things are killed

Minutes 2026-01-22 - Revision history

Freya: Freya moved page Minutes 2026-01-23 to Minutes 2026-01-22: put it under the wrong name