Fix open-ended params for api_json.log

changelogs/unreleased/53155-structured-logs-params-array.yml

+---
+title: Use key-value pair arrays for API query parameter logging instead of hashes
+merge_request: 22623
+author:
+type: other

doc/administration/logs.md

@@ -84,7 +84,7 @@ Introduced in GitLab 10.0, this file lives in
 It helps you see requests made directly to the API. For example:
 
 ```json
-{"time":"2017-10-10T12:30:11.579Z","severity":"INFO","duration":16.84,"db":1.57,"view":15.27,"status":200,"method":"POST","path":"/api/v4/internal/allowed","params":{"action":"git-upload-pack","changes":"_any","gl_repository":null,"project":"root/foobar.git","protocol":"ssh","env":"{}","key_id":"[FILTERED]","secret_token":"[FILTERED]"},"host":"127.0.0.1","ip":"127.0.0.1","ua":"Ruby"}
+{"time":"2018-10-29T12:49:42.123Z","severity":"INFO","duration":709.08,"db":14.59,"view":694.49,"status":200,"method":"GET","path":"/api/v4/projects","params":[{"key":"action","value":"git-upload-pack"},{"key":"changes","value":"_any"},{"key":"key_id","value":"secret"},{"key":"secret_token","value":"[FILTERED]"}],"host":"localhost","ip":"::1","ua":"Ruby","route":"/api/:version/projects","user_id":1,"username":"root","queue_duration":100.31,"gitaly_calls":30}
 ```
 
 This entry above shows an access to an internal endpoint to check whether an

lib/gitlab/grape_logging/formatters/lograge_with_timestamp.rb

@@ -6,7 +6,7 @@ module Gitlab
 
         def call(severity, datetime, _, data)
           time = data.delete :time
-          data[:params] = utf8_encode_values(data[:params]) if data.has_key?(:params)
+          data[:params] = process_params(data)
 
           attributes = {
             time: datetime.utc.iso8601(3),
@@ -20,6 +20,14 @@ module Gitlab
 
         private
 
+        def process_params(data)
+          return [] unless data.has_key?(:params)
+
+          data[:params]
+            .each_pair
+            .map { |k, v| { key: k, value: utf8_encode_values(v) } }
+        end
+
         def utf8_encode_values(data)
           case data
           when Hash