docker - Vagrant up --no-parallel flag meaning -

do know vagrant --no-parallel flag does? found in docs should use whenever linkink 2 different containers within same vagrantfile.

vagrant.configure(vagrantfile_api_version) |config|     config.vm.define "a" |app|         app.vm.provider "docker" |d|             d.name = "a"             d.image = "a"         end     end     config.vm.define "b" |app|         app.vm.provider "docker" |d|             d.name = "b"             d.image = "b"             d.link("a:a")         end     end end 

what should run if have vagrantfile looking this?

vagrant --no-parallel && vagrant b 

or

vagrant && vagrant b --no-parallel 

or

vagrant --no-parallel 

?

--no-parallel option makes sense when vagrant up used bring multiple machines altogether: when vagrantfile declares multiple machines , vagrant up either given no machine names or multiple machine names. in case, if provider supports (and yes, docker provider indeed), vagrant attempt bring requested machines in parallel, unless --no-parallel given.

so docker provider, when linking containers, 1 may use --no-paralel when bringing multiple machines altogether:

$ vagrant --no-parallel 

or

$ vagrant /regex match machine names/ --no-parallel 

however, if bring machines one-by-one separate commands, have no effect (no harm either) if --no-parallel specified or not. 1 may do:

$ vagrant && vagrant b