FEATURE: Add detailed OIDC request and response logs

This makes use of Faraday middleware to log precise details about all requests made by the OAuth2 gem. This should make it easier to debug configuration issues

lib/openid_connect_authenticator.rb

@@ -64,6 +64,17 @@ class OpenIDConnectAuthenticator < Auth::ManagedAuthenticator
           token_params: token_params,
           passthrough_authorize_options: SiteSetting.openid_connect_authorize_parameters.split("|")
         )
+
+        if SiteSetting.openid_connect_verbose_logging
+          opts[:client_options][:connection_build] = lambda { |builder|
+            builder.response :logger, Rails.logger, { bodies: true, formatter: OIDCFaradayFormatter }
+
+            # Default stack:
+            builder.request :url_encoded             # form-encode POST params
+            builder.adapter Faraday.default_adapter  # make requests with Net::HTTP
+          }
+        end
+
       }
   end
 end

lib/openid_connect_faraday_formatter.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require 'faraday/logging/formatter'
+class OIDCFaradayFormatter < Faraday::Logging::Formatter
+  def request(env)
+    warn <<~LOG
+      OIDC Debugging: request #{env.method.upcase} #{env.url.to_s}
+
+      Headers: #{env.request_headers}
+
+      Body: #{env[:body]}
+    LOG
+  end
+
+  def response(env)
+    warn <<~LOG
+      OIDC Debugging: response status #{env.status}
+
+      From #{env.method.upcase} #{env.url.to_s}
+
+      Headers: #{env.response_headers}
+
+      Body: #{env[:body]}
+    LOG
+  end
+end

plugin.rb

@@ -6,6 +6,7 @@
 # authors: David Taylor
 # url: https://github.com/discourse/discourse-openid-connect
 
+require_relative "lib/openid_connect_faraday_formatter"
 require_relative "lib/omniauth_open_id_connect"
 require_relative "lib/openid_connect_authenticator"