abstractmachines

How to calculate probability

Counting Distinct Objects

Combinations and Permutations

Combinations: Order Doesn't Matter

$$ C = \frac{n!}{(n-r)!r!}$$

abstractmachines

• https://dave.cheney.net/practical-go/presentations/qcon-china.html

abstractmachines

Debugging Kubernetes Flow Chart

Not sure of the source of this

abstractmachines

Kubernetes envtest

A testing environment for Kubernetes

Note: Everything mentioned here is also in the Controller Runtime's pkg envtest docs.

envtest can run on a local control plane, or an existing cluster.

• To start up a local control plane, envtest spins up a local instance of control plane binaries. These would be, etcd and kube-apiserver. It's available as a package under controller-runtime.
• Alternatively, an existing cluster can be used to run envtest, by loading up CRDs and client config.

abstractmachines

Open Source Reading Material

• https://steveklabnik.com/writing/the-culture-war-at-the-heart-of-open-source
• https://steveklabnik.com/writing/what-comes-after-open-source

abstractmachines

How to keep VSCode's Go Extension from removing Go imports while developing

We would think this would be enough for VSCode's Go Linter/formatter, but nopes:

{
  "editor.formatOnSave": false,
}

We instead need to do this:

abstractmachines

Taints, tolerations and node affinity : the e-magnetism of Kubernetes Nodes in the Kube Scheduler

We can think of Node Affinity as analagous analogus to magnetic attraction;

We can think of Node Taints as the complement of that (magnetic repulsion);

We can think of the determinant of a Node's eventual location as being "up to the Kube scheduler.

That's why we'll often have an effect of NoSchedule for nodes we'll want an exception of sorts for.

• See Scheduling/Eviction: Taints and Tolerations.

abstractmachines

// Receiver arguments: https://tour.golang.org/methods/1
// Factory patterns:
// https://www.sohamkamani.com/golang/2018-06-20-golang-factory-patterns/
// https://stackoverflow.com/questions/49712313/golang-factory-method

package main

import "fmt"

type Instrument struct {

abstractmachines

Concurrency: Time Sharing For Multiple Processes (Single Core).

• One CPU, one "pipeline" / shift register / ALU

Parallelism: Separate Cores, separate computations. Parallel "pipelines." Think multiple shift registers, ALUs.

> Read more: http://tutorials.jenkov.com/java-concurrency/concurrency-vs-parallelism.html#concurrency-vs-parallelism-tutorial-video

abstractmachines

Python VSCode settings.json w black and flake8

{
    "editor.formatOnSave": true,
    "python.formatting.provider": "black",
    "files.insertFinalNewline": true,
    "python.testing.pytestEnabled": true,
    "python.linting.pylintEnabled": false,
 "python.linting.flake8Enabled": true,