Planning

Step 1

This is a JSON file that records teachers, TAs and students for the DevOps course. For each person, we have a given name, role and email. The roles can be "Teacher", "TA" or "Student". The emails are school emails, and always formatted as <name>@mail.com.

{
    {
        "name": "Larissa",
        "role": "Teacher",
        "email": "larissa@mail.com"
    },
    {
        "name": "Eric",
        "role": "TA",
        "email": "eric@mail.com"
    },
    {
        "name": "Sofia",
        "role": "TA",
        "email": "sofia@mail.com"
    },
    {
        "name": "David",
        "role": "Student",
        "email": "david@mail.com"
    },
    {
        "name": "Herdi",
        "role": "Student",
        "email": "herdi@mail.com"
    }
}

Edit the JSON and extend it with your own credentials!

Step 2

Intro to Dhall

• Type safety/typing
• Enums
• Functions

Step 3

let Role = < Teacher | TA | Student >

let makeUser =
      \(name : Text) ->
      \(role : Role) ->
        { name = name
        , role = role
        , email = "${name}@mail.com"
        }

in  [ makeUser "Larissa" Role.Teacher
    , makeUser "Eric" Role.TA
    , makeUser "Sofia" Role.TA
    , makeUser "David" Role.Student
    , makeUser "Herdi" Role.Student
    ]

let Role = < Teacher | TA | Student >

let User : Type =
      { name : Text
      , role : Role
      , email : Text
      }

let makeUser : Text -> Role -> User =
      \(name : Text) ->
      \(role : Role) ->
        { name = name
        , role = role
        , email = "${name}@mail.com"
        }

in  [ makeUser "Larissa" Role.Teacher
    , makeUser "Eric" Role.TA
    , makeUser "Sofia" Role.TA
    , makeUser "David" Role.Student
    , makeUser "Herdi" Role.Student
    ]
    : List User

Step 4

The DevOps course has decided to migrate to YAML, and you now have to convert the JSON to YAML. Fortunately this is a breeze, since you are using Dhall.

• Create a YAML
• Create a CSV, by defining how it should look

Step 5

Canonical forms

• How do we check equivalence between all three config files?
• Define canonical form and use it to check!