Starting Cachex via Supervisor.start_link

[lucavenir]

Hello there,

I really hope I'm not wasting anyone's time here, but I simply went and read the "welcome page/guide" of this (awesome!) package and I've got myself a papercut.

I read from the docs, in regards of starting Cachex in a supervision tree:

children = [
  {Cachex, [:my_cache]},     # with default options
  {Cachex, [:my_cache, []]}  # with custom options
]

So I try this in my phoenix application; I copy-paste the first line in my list of children:

children = [
  ...,
  {Cachex, [:my_cache]},
]

But, Supervisor.start_link gives this error:

** (Mix) Could not start application my_app: MyApp.Application.start(:normal, []) returned an error: shutdown: failed to start child: Cachex
    ** (EXIT) :invalid_name

Whereas, if I write my cache name like below, no error is raised on startup:

{Cachex, name: :my_cache},

Which makes sense, AFAIK supervisor wants a keyword list as a second argument of the tuple.

But... am I doing this right? Am I missing something?

[lucavenir]

By the way I've read #380 before opening this issue. I've updated my cachex dependency to match exactly 4.0.1, but the behavior is identical.

[whitfin]

Hi @lucavenir!

At a glance, yes, the docs for this are wrong and need to be updated. I can double check when I get a moment, just in case!

[whitfin]

@lucavenir instead of changing the docs, I decided to just make sure that the form shown in the README also works - I did that in #384. I also added checks to make sure this is tested going forward!

It should be released in v4.0.2 if you want to double check that it's all good for you now!

[lucavenir]

Oh, okay! I'll try this out ASAP.

If anyone's having this same problem, I am currently starting two different Cachex instances like so:

[
  Supervisor.child_spec(
    {Cachex, name: MyApp.Whatever.Module.One},
    id: MyApp.Whatever.Module.One
  ),
  Supervisor.child_spec(
    {Cachex, name: MyApp.Whatever.Module.Two},
    id: MyApp.Whatever.Module.Two
  )
]

I did this when trying to make it work: Supervisor.start_link/2 gives a nice error which shows you the different options.