Custom Servers + BYO `express` cleanup tasks

A master-list of tasks to do after #1109 lands.

• Stop hard-coding the admin path on static build
• Rename all the paths to routes (to be consistent with the StaticApp API of accepting a route (the URL) and a path (local file system).
  • Change FileAdapter API from { route, directory } -> { path, src } to match everything else. #1644

---

• Get the build() step working for static assets.
• Rename options for server-static to path for the URL portion, and src for the file-system portion.
• Add more tests for the different edge cases of the prepare method + CLI (currently written as test.todo() in the code as placeholders) #1109
• Remove keystone from @keystone-alpha/app-admin’s constructor (it’s passed into the prepareMiddlewares() function. #1197
• There is a port parameter being passed to prepareMiddleware() which is only used for some console.logs. I want to move all that into the default server and stop passing the port parameter. #1203
• Most of the custom servers now only exist to insert default data. Can we provide a better API for that which is setup in index.js, or (better yet) is a separate script that is run only once? This would make most of our custom servers go away leaving us with a nice clean index.js everywhere.
  • Provide an alternate mechanism for running things after connect (#1200)
  • Remove the custom servers (#1204)
• This new structure makes it easier to start listening to requests immediately rather than waiting for all of KS to be ready + the AdminUI, etc. We can avoid the bad DX of having to hit F5 constantly until it boots up. (#1205)
• ~Move the default server into its own file default-server.js so it’s easier to reference / discover for app developers.~ The default server is now heavily customised and might actually be confusing for devs, so I wont be doing this.
• Documentation #1214
  • The expected API for servers.
  • Different ways to specify servers:
    • Export the servers array from index.js
    • Create a custom server.js and export the servers array from index.js
    • Create a custom server.js which instantiates all of its own middlewares
  • How to customise the GraphQL middleware (it’s just another server 😉)

[jesstelford]

@jed see #1205 - it should work for any app (because it happens before they’re initialised)

[MadeByMike]

Current PRs will resolve all outstanding issues here