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>
That job was a hacky solution to a real race condition. This removes the
hack without re-introducing the race.
Signed-off-by: Solomon Hykes <solomon@docker.com>
This disentangles the following functions, which were previously all mixed together:
* 1) Waiting for jobs to terminate when shutting down
* 2) Handling signals in the Docker daemon
* 3) Per-subsystem cleanup handlers
* 4) pidfile management
Responsibilities are dispatched as follows:
* Signal traps are set in `main`, and trigger `engine.Shutdown`
* `engine.Shutdown` coordinates cleanup by waiting for jobs to complete, and calling shutdown handlers
* To perform cleanup at shutdown, each subsystem registers handlers with `engine.OnShutdown`
* `daemon` is one subsystem, so it registers cleanup via `engine.OnShutdown`.
* `daemon` owns the pidfile, which is used to lock access to `/var/lib/docker`. Part of its cleanup is to remove the pidfile.
Signed-off-by: Solomon Hykes <solomon@docker.com>
This works mostly by refactoring our "main" package to be careful about what it imports based on the daemon build tag. :)
Also, I've updated Travis to test "client-only" compilation after it tests the daemon version.
Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
