Running code on Phoenix start?

Questions & Help Questions
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3

I tried adding a child to the supervision tree which boiled down to this:

defmodule MyApp.Application do
  alias MyApp.Contexts.MyContext
  use Application

  def start(_type, _args) do
    import Supervisor.Spec, warn: false
    
    children = [
      supervisor(MyApp.Repo, []),
      worker(Task, [&MyContext.warm_up_cache/0], restart: :temporary)
    ]
    
    opts = [strategy: :one_for_one, name: MyApp.Supervisor]
    Supervisor.start_link(children, opts)
  end
end

That works, but blows up with errors when the database is down or being provisioned (which is obvious in retrospect). Instead, I think what I want in this case is a blocking task: i.e. wait to start the rest of the app until this one thing is complete.

Does someone have a good example of how to do something like this? My example here is warming up the cache.

Thanks for any guidance!