Service definitions can export environment variables.

src/main.cr

@@ -67,6 +67,11 @@ class ServiceDefinition
 		checks: {
 			type: Array(Checks),
 			default: [] of Checks
+		},
+		environment_variables: {
+			type: Array(String),
+			key: "environment-variables",
+			default: [] of String
 		}
 	})
 
@@ -259,6 +264,17 @@ class Service
 	def export_environment_variables
 		ENV["SERVICE_ENVIRONMENT"] = @environment.name
 		ENV["SERVICE_ENVIRONMENT_TYPE"] = @environment.type.to_s
+
+		# FIXME: Parsing should probably be done… when parsing the file.
+		# FIXME: Parsing is probably a bit primitive. Maybe this isn’t the right way of defining this.
+		@reference.environment_variables.each do |string|
+			# FIXME: Should probably deserve a warning.
+			variable = string.match(/^[^=]*=/).not_nil![0]
+			value = string[variable.size..string.size]
+			variable = variable[0..variable.size-2]
+
+			ENV[variable] = value
+		end
 	end
 	private def evaluate(string)
 		string.gsub /%{[a-zA-Z]+}/ do |match|