URL Shortener

URL shortener will be one of the first party applications developed and published by pcloud team.

Background

PCloud customers, especially businesses, will want to share documents with easy to find and intuitive names. For example internal design document hosted at https://docs.google.com/document/d/X0N4-M0oI2P9l8NMRN6JZR9ETo1fpPIMUf_LUPB5Omgw/edit can be named and shared as https://go/auth-service-dd

Goals

  • Authenticated user must be able to assign name to any given URL address.
  • User can choose name manually or generate it randomly.
  • User must be able to view list of all named URLs owned by them.
  • [Stretch] User must be able to transfer ownership of the name to the other user.
  • [Stretch] Administrator of the system must be able to act as any other user.

Non-goals

  • Authentication will be implemented outside of this service. URL shortener can assume that if user can access the page that user has already been authorized.
  • [Maybe] Changing address of alread created entry must not be possible.

Technichal overview

URL Shortener service will serve only one page at the root path /. At the top of the page must be a form to create new named address entry. And below the form must be listed all the named addresses created by currently logged in user.

Form will have two input texts: one to input the address user wants to name and second one for the name itself. Name can be either entered manually or auto-generated by server (user will have to click Randomize button. Clicking Create button must store new named entry in the storage.

Storage component will have following interface:

type NamedAddress struct {
	// Name of the address. Must be unique across the service.
	Name    string
	Address string
	OwnerId string
	Active  bool
}

type Store interface {
	// Creates new named address.
	Create(name, address, ownerId string) error
	// Activates given named address. Does nothing if named address is already active.
	Activate(name string) error
	// Deactivates given named address. Does nothing if named address is already inactive.
	Deactivate(name string) error
	// Transfers ownership of the given named address to new owner.
	ChangeOwner(name, ownerId string) error
	// Retreives all named addresses owned by given owner.
	List(ownerId string) ([]NamedAddress, error)
}

We will have single implementation of the Store interface backed by go-sqlite3. Path to the sqlite3 file will be passed as a flag, which can be parsed and accessed using standard flag package, for example ./url-shortener --db-path=/path/to/sqlite3.db. At the startup server must check if file at given path exists and if not create and initialize (create table for named address entries) it with new sqlite db.

Standard net/http is sufficient to implement the web server. Server will have just two handlers registered:

  • GET / - if request path is / render form and list of addresses owner by current user, otherwise (for example /foo) server will find named address for foo and send HTTP redirect (StatusSeeOther) to address given name was assigned to.
  • POST / - to create new named address entry

Single HTML template will be sufficient to render the home page via html/template package. And embed package will be used to embed said HTML template into the final binary.

Implementation will go to apps/url-shortener directory.