This change is part of the efforts to make DockerManager implement the Runtime
interface.
The change also modifies the interface slightly to work with existing
code, and aggregates the type converting functions to convert.go.
This change refactors the GetPods function and add some basic unit tests.
We should start migrating docker specific tests from kubelet_test to
manager_test.go.
We want to stop leaking more docker details into kubelet, and we also want to
consolidate some of the existing docker interfaces/structs. This change creates
DockerManager as the new home of some functions in dockertools/docker.go. It
also absorbs containerRunner. In addition, GetDockerPodStatus is renamed to
GetPodStatus with the entire pod passed to it so that it is simialr to the what
is defined in the container Runtime interface.
Eventually, DockerManager should implement the container Runtime interface, and
integrate DockerCache with a flag to turn on/off caching. Code in kubelet.go
should not be using docker client directly.
