caindy

WSL2 container development with Moby

Building, pulling, pushing, and running containers is something many developers do often without even thinking. Most of my development over the past couple of years has been exclusively in a Linux environment, specifically WSL2.

Even prior to the recent licensing changes to Docker Desktop, I found myself increasingly as an engineer whose workflow didn't line up with my tools. I never used the GUI features. I never built Windows containers. I used kind or k3d instead of the Docker Kubernetes functionality. I never mounted the Windows filesystem into my containers. And I certainly didn't enjoy frequent downtime caused by updates for those features that I wasn't using. I wanted the container experience in my dev environment to match what I got on a server - just the runtime & tools.

That said, I still like shiny new (or not-so-new but I never see anyone use them

caindy

open System
let xmas = DateTime.Parse("December 25")
let (|ChristmasEve|ChristmasDay|Twelvetide|NearlyThere|TisTheSeason|NotChristmas|) (d : DateTime) =
  match (d - xmas).Days with
  | 0  -> ChristmasDay d.Year
  | -1 -> ChristmasEve d.Year
  | t when t > 0 && t < 12 -> Twelvetide t
  | t when t > -7  && t < 0 -> NearlyThere
  | t when t > -25 && t < 0 -> TisTheSeason
  | _ -> NotChristmas

caindy

(*
let shareMsgParser = fun j -> jsonParse {
  let! shareWith = j?users
  return Share shareWith }
*)

let inline (?) (j : JsonValue) (k : string) =
  match j with
  | JObject props -> jget props k
  | _ -> Failure <| sprintf "%s not found in %A" k j

caindy

// this works...
let n =
  match System.Int32.TryParse("10") with
  | (true,n) -> Some n | _ -> None

// but this is...  
let inline tryParse (s : string) : ^o option =
  let mutable o = Unchecked.defaultof<(^o)>
  if (^o : (static member TryParse: string * ^o byref -> bool) (s, &o)) then Some o else None

caindy

// link to competition: https://www.kaggle.com/c/whats-cooking/

//reference deelde with fsharp charting
#r "../packages/Deedle.1.2.4/lib/net40/Deedle.dll"
#r "../packages/FSharp.Charting.0.90.12/lib/net40/FSharp.Charting.dll"
#I "../packages/FSharp.Charting.0.90.12"
#load "FSharp.Charting.fsx"
#r "../packages/Newtonsoft.Json.7.0.1/lib/net45/Newtonsoft.Json.dll"

open System

caindy

A comparison of Collection+JSON, HAL, JSON-LD and SIREN media types.

Discussion at 

http://sookocheff.com/posts/2014-03-11-on-choosing-a-hypermedia-format/

caindy

Make it real

Ideas are cheap. Make a prototype, sketch a CLI session, draw a wireframe. Discuss around concrete examples, not hand-waving abstractions. Don't say you did something, provide a URL that proves it.

Ship it

Nothing is real until it's being used by a real user. This doesn't mean you make a prototype in the morning and blog about it in the evening. It means you find one person you believe your product will help and try to get them to use it.

Do it with style

caindy

[<AutoOpen>]
module Auto =
  type Result<'s, 'f> =
  | Success of 's
  | Failure of 'f
  open System
  open System.Runtime.CompilerServices
  open System.Collections.Generic
  open Newtonsoft.Json.Linq

caindy

#! /bin/bash

if hash brew 2>/dev/null; then
  echo "Found Homebrew"
else
  echo >&2 "Please install Homebrew"
  exit 1
fi

if hash fsharpi 2>/dev/null; then

caindy

open System.Numerics

let (|Rect|)  (x: Complex) = (x.Real, x.Imaginary)
let (|Polar|) (x: Complex) = (x.Magnitude, x.Phase)

//conversion functions easily expressed in terms of active patterns
let toRect  = function | Rect(r, i) -> (r, i)
let toPolar = function | Polar(m, p) -> (m, p)

//following two functions are equivalent, but the former reads better IMO