(UndefinedFunctionError) function CAStore.file_path/0 is undefined (module CAStore is not available)

Hello guys I cant connect to MySQL using ecto_sql and myxql connect to mysql at planetscale

I have config file dev.exs below

config :myproject, Myproject.Repo,
  username: "asdf",
  password: "asdf",
  hostname: "hostname,
  database: "wbdev-db",
  ssl: true,
  ssl_opts: [
    verify: :verify_peer,
    cacertfile: CAStore.file_path(),
    server_name_indication: String.to_charlist("hostname"),
    customize_hostname_check: [
      match_fun: :public_key.pkix_verify_hostname_match_fun(:https)
    ]
  ],
  stacktrace: true,
  show_sensitive_data_on_connection_error: true,
  pool_size: 10

Error message

** (UndefinedFunctionError) function CAStore.file_path/0 is undefined (module CAStore is not available)
    CAStore.file_path()
    /Users/macbookpro/Documents/myproject/config/dev.exs:12: (file)
    /Users/macbookpro/Documents/myproject/config/config.exs:64: (file)
    (stdlib 4.2) erl_eval.erl:748: :erl_eval.do_apply/7
    (stdlib 4.2) erl_eval.erl:961: :erl_eval.expr_list/7
    (stdlib 4.2) erl_eval.erl:290: :erl_eval.expr/6
    (stdlib 4.2) erl_eval.erl:282: :erl_eval.expr/6

CAStore is undefined if I run it in Supervisor tree it work fine MyXQL.start_link(db_config)

What does your CAStore module look like? It might be a namespacing issue.

For example, if you have something like defmodule Myproject.CAStore, you’d need to alias it or use the full module name in your dev.exs.

# either add
alias Myproject.CAStore
# or use
Myproject.CAStore.file_path()
# instead of
CAStore.file_path()
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Thank for response. CAStore is work when I start it in application.ex for me I want to config in dev.exs and runtime.exs CAStore is not work

Can you share your working application.ex and ca_store.ex?

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sorry ca_store.ex doesn’t exist cause
here is my application.ex I think CAStore might use in Ecto Im not sure

defmodule Wb.Application do
  # See https://hexdocs.pm/elixir/Application.html
  # for more information on OTP Applications
  @moduledoc false

  use Application

  @impl true
  def start(_type, _args) do
    children = [
      # Start the Telemetry supervisor
      WbWeb.Telemetry,
      # Start the Ecto repository
      # Wb.Repo,
      # Start the PubSub system
      {Phoenix.PubSub, name: Wb.PubSub},
      WbWeb.Presence,
      # Start the Endpoint (http/https)
      WbWeb.Endpoint,
      # Start a worker by calling: Wb.Worker.start_link(arg)
      # {Wb.Worker, arg}
      Wb.Tracker.TrackerSupervisor,
      {
        MyXQL,
        username: "",
        database: "wbdev-db",
        hostname: "",
        password: "",
        ssl: true,
        ssl_opts: [
          verify: :verify_peer,
          cacertfile: CAStore.file_path(),
          server_name_indication: String.to_charlist("aws.connect.psdb.cloud"),
          customize_hostname_check: [
            match_fun: :public_key.pkix_verify_hostname_match_fun(:https)
          ]
        ],
      }
    ]

    # See https://hexdocs.pm/elixir/Supervisor.html
    # for other strategies and supported options
    opts = [strategy: :one_for_one, name: Wb.Supervisor]
    Supervisor.start_link(children, opts)
  end

  # Tell Phoenix to update the endpoint configuration
  # whenever the application is updated.
  @impl true
  def config_change(changed, _new, removed) do
    WbWeb.Endpoint.config_change(changed, removed)
    :ok
  end
end

Can you show your mix.exs? Do you have the :castore package in the deps?

1 Like

Ahh, CAStore.file_path() is from the dependency castore.

Would config files even have access to dependencies? If I recall correctly, config files are read at build time, which is before the application gets compiled and its dependencies loaded.

Edited To Add: https://elixir-lang.org/getting-started/mix-otp/config-and-releases.html#configuration

Configuration

Configuration files provide a mechanism for us to configure the environment of any application. Elixir provides two configuration entry points:

  • config/config.exs - this file is read at build time, before we compile our application and before we even load our dependencies. This means we can’t access the code in our application nor in our dependencies. However, it means we can control how they are compiled
  • config/runtime.exs - this file is read after our application and dependencies are compiled and therefore it can configure how our application works at runtime. If you want to read system environment variables (via System.get_env/1) or any sort of external configuration, this is the appropriate place to do so
1 Like

I have installed it and test it doesn’t work

thanks you I will try another solution

Were you able to resolve this? The planetscale connection configuration tool suggests to add the following to your dev.exs which seems to be incorrect. I see that you’ve done the same in your project.

hostname = "aws.connect.psdb.cloud"
{:ok, pid} = MyXQL.start_link(username: "*******",
  database: "*******",
  hostname: hostname,
  password: System.get_env("DATABASE_PASSWORD"),
  ssl: true,
  ssl_opts: [
    verify: :verify_peer,
    cacertfile: CAStore.file_path(),
    server_name_indication: String.to_charlist(hostname),
    customize_hostname_check: [
      match_fun: :public_key.pkix_verify_hostname_match_fun(:https)
    ]
  ]
)

my config in dev.exs username and password I remove it bcoz it can be public

  • the reason that It doest work and error CAStore is undefined
  • MySQL it not working with EtcoSQL can config with Repo
  • if start MyXQL under the Supervisor tree (application.ex) it work.

Just a heads up, that planetscale connection example has the configuration/connection code in a mix task where the castore dependency is available. Putting that code in dev.exs which gets called by config.exs during build time results in an error since dependencies are not available then.

To configure and connect during build time, try specifying the file path directly rather than through CAStore.file_path(). To use CAStore.file_path(), try adding the configuration/connection code into runtime.exs which is read after dependencies are available.

1 Like

Thanks you so much now I can connect to planet-scale

1 Like