Previously, long lived CLI plugin processes weren't
properly handled
(see: https://github.com/docker/cli/issues/4402)
resulting in plugin processes being left behind
running, after the CLI process exits.
This commit changes the plugin handling code to open
an abstract unix socket before running the plugin and
passing it to the plugin process, and changes the
signal handling on the CLI side to close this socket
which tells the plugin that it should exit.
This implementation makes use of sockets instead of
simply setting PDEATHSIG on the plugin process
so that it will work on both BSDs, assorted UNIXes
and Windows.
Signed-off-by: Laura Brehm <laurabrehm@hey.com>
Laura Brehm