This changes the way the exec drivers work by not specifing a -driver
flag on reexec. For each of the exec drivers they register their own
functions that will be matched aginst the argv 0 on exec and called if
they match.
This also allows any functionality to be added to docker so that the
binary can be reexec'd and any type of function can be called. I moved
the flag parsing on docker exec to the specific initializers so that the
implementations do not bleed into one another. This also allows for
more flexability within reexec initializers to specify their own flags
and options.
Signed-off-by: Michael Crosby <michael@docker.com>
This uses "," instead of spaces so that the flags are parsed correctly
and also does not do a strings.Split on an empty string because
strings.Split will return a slice with one element, and empty string
causing parsing to fail when it validates that the cap exists.
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
