Sub-libraries not swapping JSON codec or using region in config

[foggy1]

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Environment

• Erlang/OTP 21 [erts-10.2.1] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [hipe] [dtrace]

Elixir 1.7.4 (compiled with Erlang/OTP 21)

• *ex_aws 2.1.0 (Hex package) (mix) locked at 2.1.0 (ex_aws) b9265152
• ex_aws_lambda 2.0.1 (Hex package) (mix) locked at 2.0.1 (ex_aws_lambda) d1904b97
• hackney 1.15.0 (Hex package) (rebar3) locked at 1.15.0 (hackney) 287a5d23

Current behavior

I have the following in my config

config :ex_aws, :our_app,
  region: "us-west-1",
  json_codec: Jason

and I have tried adding and removing the following as well

config :ex_aws_lambda, :our_app,
  region: "us-west-2",
  json_codec: Jason

When I make an ExAws.request() with any given ExAws.Lambda function, it tries to go to the default us-east-1, ignoring both configs.

Additionally, if I do not have Poison installed, AWS requests (when I specific us-west-2 in the request) fail since they try to use Poison instead of Jason.

I have had a similar problem with the ex_aws_cloudwatch library on a separate project.

Expected behavior

I expect the config to be respected since the docs indicate that it should be. I initially thought this was an issue in the sub-libraries but the error ends up falling back in the core ExAws operation library.

** (UndefinedFunctionError) function Poison.encode!/1 is undefined (module Poison is not available)
    Poison.encode!(%{the map i was trying to encode})
    (ex_aws) lib/ex_aws/request.ex:19: ExAws.Request.request/6
    (ex_aws) lib/ex_aws/operation/json.ex:49: ExAws.Operation.ExAws.Operation.JSON.perform/2

If the issue is in the sub-libraries, it must just be a matter of propagating the config changes downwards. I would be happy to help with this if someone can point me in the right direction.

It's not hard to install Poison or to type us-west-2 in my ExAws.request fields, but it seems silly that I should have to install two JSON libraries or specifiy a single region all over the place.

[benwilson512]

Hey @foggy1 sorry to hear you're having issues.

config :ex_aws, :our_app,
  region: "us-west-1",
  json_codec: Jason

Why are you doing config this way? Just do:

config :ex_aws,
  region: "us-west-1",
  json_codec: Jason

[foggy1]

Ugh, thank you.