FAB-9759 Make controllers instantiate by intf

Presently, the core/container package reaches directly into the
core/container/inproccontroller and core/container/dockercontroller
packages.  Because these packages need to implement interfaces for
core/container, this creates an awkward core/container/api directory.

In reality, these VM provider types should be registered as part of the
construction of the container vm controller.  This CR takes the first
step of instantiating the providers by interface, rather than by
reaching into the package directly.

Change-Id: Ifed8a01a68fb11cab6058a15242f4cda335d2297
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>

core/container/controller.go

@@ -21,6 +21,10 @@ import (
 	pb "github.com/hyperledger/fabric/protos/peer"
 )
 
+type VMProvider interface {
+	NewVM() api.VM
+}
+
 type refCountedLock struct {
 	refCount int
 	lock     *sync.RWMutex
@@ -34,6 +38,7 @@ type VMController struct {
 	sync.RWMutex
 	// Handlers for each chaincode
 	containerLocks map[string]*refCountedLock
+	vmProviders    map[string]VMProvider
 }
 
 var vmLogger = flogging.MustGetLogger("container")
@@ -42,6 +47,10 @@ var vmLogger = flogging.MustGetLogger("container")
 func NewVMController() *VMController {
 	return &VMController{
 		containerLocks: make(map[string]*refCountedLock),
+		vmProviders: map[string]VMProvider{
+			DOCKER: dockercontroller.NewProvider(),
+			SYSTEM: inproccontroller.NewProvider(),
+		},
 	}
 }
 
@@ -52,17 +61,11 @@ const (
 )
 
 func (vmc *VMController) newVM(typ string) api.VM {
-	var v api.VM
-
-	switch typ {
-	case DOCKER:
-		v = dockercontroller.NewDockerVM()
-	case SYSTEM:
-		v = &inproccontroller.InprocVM{}
-	default:
+	v, ok := vmc.vmProviders[typ]
+	if !ok {
 		vmLogger.Panicf("Programming error: unsupported VM type: %s", typ)
 	}
-	return v
+	return v.NewVM()
 }
 
 func (vmc *VMController) lockContainer(id string) {

core/container/dockercontroller/dockercontroller.go

@@ -85,6 +85,19 @@ type dockerClient interface {
 	RemoveContainer(opts docker.RemoveContainerOptions) error
 }
 
+// Controller implements container.VMProvider
+type Provider struct{}
+
+// NewProvider creates a new instance of Provider
+func NewProvider() *Provider {
+	return &Provider{}
+}
+
+// NewVM creates a new DockerVM instance
+func (p *Provider) NewVM() container.VM {
+	return NewDockerVM()
+}
+
 // NewDockerVM returns a new DockerVM instance
 func NewDockerVM() *DockerVM {
 	vm := DockerVM{}

core/container/inproccontroller/inproccontroller.go

@@ -19,6 +19,19 @@ import (
 	"golang.org/x/net/context"
 )
 
+// Provider implements container.VMProvider
+type Provider struct{}
+
+// NewProvider creates a new instances of Provider
+func NewProvider() *Provider {
+	return &Provider{}
+}
+
+// NewVM creates an inproc VM instance
+func (c *Provider) NewVM() container.VM {
+	return &InprocVM{}
+}
+
 type inprocContainer struct {
 	chaincode shim.Chaincode
 	running   bool