It looks like there is no way to specify some build args (--build-arg parameter for docker build) to build an image using the "dockerfile" option. It supports "args", but only to pass to subsequents docker run calls.
Code changed in jenkins User: Andrew Bayer Path: pipeline-model-definition/src/main/java/org/jenkinsci/plugins/pipeline/modeldefinition/agent/impl/DockerPipelineFromDockerfile.java pipeline-model-definition/src/main/resources/org/jenkinsci/plugins/pipeline/modeldefinition/agent/impl/DockerPipelineFromDockerfileScript.groovy pipeline-model-definition/src/test/java/org/jenkinsci/plugins/pipeline/modeldefinition/AgentTest.java pipeline-model-definition/src/test/resources/additionalDockerBuildArgs.groovy http://jenkins-ci.org/commit/pipeline-model-definition-plugin/04206b8d9122a9b87a0352ce963730212baaa919 Log: [FIXED JENKINS-42693] Add additionalBuildArgs dockerfile parameter
Allows specifying like dockerfile { additionalBuildArgs "--build-arg someArg=someValue" } which will get added to the "docker build ..." command line call.