fn build

$ fn build

DEVELOPMENT COMMANDS
  fn build -   Build function version
               
USAGE
  fn [global options] build [command options] [function-subdirectory] 
    
DESCRIPTION
  This command builds a new function.
    
COMMAND OPTIONS
  --verbose, -v                  Verbose mode
  --no-cache                     Don't use docker cache
  --build-arg value              Set build-time variables
  --working-dir value, -w value  Specify the working directory to build a function, must be the full path.
  

Some link