Refactored the driver api so that is aligns well with the design
of endpoint lifecycle becoming decoupled from the container lifecycle.
Introduced go interfaces to obtain address information during CreateEndpoint.
Go interfaces are also used to get data from driver during join.
This sort of deisgn hides the libnetwork specific type details from drivers.
Another adjustment is to provide a list of interfaces during CreateEndpoint. The
goal of this is many-fold:
* To indicate to the driver that IP address has been assigned by some other
entity (like a user wanting to use their own static IP for an endpoint/container)
and asking the driver to honor this. Driver may reject this configuration
and return an error but it may not try to allocate an IP address and override
the passed one.
* To indicate to the driver that IP address has already been allocated once
for this endpoint by an instance of the same driver in some docker host
in the cluster and this is merely a notification about that endpoint and the
allocated resources.
* In case the list of interfaces is empty the driver is required to allocate and
assign IP addresses for this endpoint.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
In the present code, each driver package provides a `New()` method
which constructs a driver of its type, which is then registered with
the controller.
However, this is not suitable for the `drivers/remote` package, since
it does not provide a (singleton) driver, but a mechanism for drivers
to be added dynamically. As a result, the implementation is oddly
dual-purpose, and a spurious `"remote"` driver is added to the
controller's list of available drivers.
Instead, it is better to provide the registration callback to each
package and let it register its own driver or drivers. That way, the
singleton driver packages can construct one and register it, and the
remote package can hook the callback up with whatever the dynamic
driver mechanism turns out to be.
NB there are some method signature changes; in particular to
controller.New, which can return an error if the built-in driver
packages fail to initialise.
Signed-off-by: Michael Bridgen <mikeb@squaremobius.net>
This commits brings in a functionality for remote drivers to register
with LibNetwork. The Built-In remote driver is responsible for the
actual "remote" plugin to be made available.
Having such a mechanism makes libnetwork core not dependent on any
external plugin mechanism and also the Libnetwork NB apis are free of
Driver interface.
Signed-off-by: Madhu Venugopal <madhu@docker.com>
This is an intial pass at the design docs.
Hopefully, we can merge this and then start accepting PRs to improve it!
Signed-off-by: Dave Tucker <dt@docker.com>
