1 files changed, 68 insertions, 0 deletions
diff --git a/gems/click_house-client/lib/click_house/client/configuration.rb b/gems/click_house-client/lib/click_house/client/configuration.rb
new file mode 100644
index 00000000000..882b37993dc
--- /dev/null
+++ b/gems/click_house-client/lib/click_house/client/configuration.rb
@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+
+module ClickHouse
+  module Client
+    class Configuration
+      # Configuration options:
+      #
+      # *register_database* (method): registers a database, the following arguments are required:
+      #   - database: database name
+      #   - url: URL and port to the HTTP interface
+      #   - username
+      #   - password
+      #   - variables (optional): configuration for the client
+      #
+      # *http_post_proc*: A callable object for invoking the HTTP request.
+      #   The object must handle the following parameters: url, headers, body
+      #   and return a Gitlab::ClickHouse::Client::Response object.
+      #
+      # *json_parser*: object for parsing JSON strings, it should respond to the "parse" method
+      #
+      # Example:
+      #
+      # Gitlab::ClickHouse::Client.configure do |c|
+      #   c.register_database(:main,
+      #     database: 'gitlab_clickhouse_test',
+      #     url: 'http://localhost:8123',
+      #     username: 'default',
+      #     password: 'clickhouse',
+      #     variables: {
+      #       join_use_nulls: 1 # treat JOINs as per SQL standard
+      #     }
+      #   )
+      #
+      #   c.http_post_proc = lambda do |url, headers, body|
+      #     options = {
+      #       headers: headers,
+      #       body: body,
+      #       allow_local_requests: false
+      #     }
+      #
+      #     response = Gitlab::HTTP.post(url, options)
+      #     Gitlab::ClickHouse::Client::Response.new(response.body, response.code)
+      #   end
+      #
+      #   c.json_parser = JSON
+      # end
+      attr_accessor :http_post_proc, :json_parser
+      attr_reader :databases
+
+      def initialize
+        @databases = {}
+        @http_post_proc = nil
+        @json_parser = JSON
+      end
+
+      def register_database(name, **args)
+        raise ConfigurationError, "The database '#{name}' is already registered" if @databases.key?(name)
+
+        @databases[name] = Database.new(**args)
+      end
+
+      def validate!
+        raise ConfigurationError, "The 'http_post_proc' option is not configured" unless @http_post_proc
+        raise ConfigurationError, "The 'json_parser' option is not configured" unless @json_parser
+      end
+    end
+  end
+end