From 7dd49516d85bcf8ed8ed888fd4d1e5133fba2daa Mon Sep 17 00:00:00 2001
From: Brian Goff <cpuguy83@gmail.com>
Date: Fri, 17 May 2019 17:01:05 -0700
Subject: [PATCH] Decouple vkubelet/* packages from providers (#626)

This makes the concept of a `Provider` wholely implemented in the cli
implementation in cmd/virtual-kubelet.

It allows us to slim down the interfaces used in vkubelet (and
vkubelet/api) to what is actually used there rather than a huge
interface that is only there to serve the CLI's needs.
---
 cmd/virtual-kubelet/commands/root/http.go | 20 ++++++--
 providers/alibabacloud/eci.go             |  6 +--
 providers/aws/fargate/cluster.go          |  4 +-
 providers/aws/provider.go                 |  6 +--
 providers/aws/provider_test.go            |  4 +-
 providers/azure/aci.go                    |  8 +--
 providers/azurebatch/batch.go             |  6 +--
 providers/azurebatch/batch_test.go        |  6 +--
 providers/cri/cri.go                      |  7 +--
 providers/huawei/cci.go                   |  6 +--
 providers/mock/mock.go                    |  9 ++--
 providers/node.go                         | 28 -----------
 providers/nomad/nomad.go                  |  5 +-
 providers/openstack/zun.go                |  5 +-
 providers/provider.go                     | 60 ++---------------------
 providers/web/broker.go                   |  6 +--
 vkubelet/api/exec.go                      | 41 +++++++++++-----
 vkubelet/api/logs.go                      | 26 +++++++---
 vkubelet/api/pods.go                      | 12 ++---
 vkubelet/{apiserver.go => api/server.go}  | 56 ++++++++++++---------
 vkubelet/api/stats.go                     | 15 +++---
 vkubelet/doc.go                           |  6 +--
 vkubelet/node.go                          | 26 ++++++++--
 vkubelet/node_test.go                     |  3 +-
 vkubelet/podcontroller.go                 | 33 +++++++++++++
 vkubelet/vkubelet.go                      |  7 ++-
 26 files changed, 217 insertions(+), 194 deletions(-)
 delete mode 100644 providers/node.go
 rename vkubelet/{apiserver.go => api/server.go} (64%)

diff --git a/cmd/virtual-kubelet/commands/root/http.go b/cmd/virtual-kubelet/commands/root/http.go
index 14e00c388..3668fe0a8 100644
--- a/cmd/virtual-kubelet/commands/root/http.go
+++ b/cmd/virtual-kubelet/commands/root/http.go
@@ -26,7 +26,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/virtual-kubelet/virtual-kubelet/log"
 	"github.com/virtual-kubelet/virtual-kubelet/providers"
-	"github.com/virtual-kubelet/virtual-kubelet/vkubelet"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 )
 
 // AcceptedCiphers is the list of accepted TLS ciphers, with known weak ciphers elided
@@ -86,7 +86,13 @@ func setupHTTPServer(ctx context.Context, p providers.Provider, cfg *apiServerCo
 		}
 
 		mux := http.NewServeMux()
-		vkubelet.AttachPodRoutes(p, mux, true)
+
+		podRoutes := api.PodHandlerConfig{
+			RunInContainer:   p.RunInContainer,
+			GetContainerLogs: p.GetContainerLogs,
+			GetPods:          p.GetPods,
+		}
+		api.AttachPodRoutes(podRoutes, mux, true)
 
 		s := &http.Server{
 			Handler:   mux,
@@ -105,7 +111,15 @@ func setupHTTPServer(ctx context.Context, p providers.Provider, cfg *apiServerCo
 		}
 
 		mux := http.NewServeMux()
-		vkubelet.AttachMetricsRoutes(p, mux)
+
+		var summaryHandlerFunc api.PodStatsSummaryHandlerFunc
+		if mp, ok := p.(providers.PodMetricsProvider); ok {
+			summaryHandlerFunc = mp.GetStatsSummary
+		}
+		podMetricsRoutes := api.PodMetricsConfig{
+			GetStatsSummary: summaryHandlerFunc,
+		}
+		api.AttachPodMetricsRoutes(podMetricsRoutes, mux)
 		s := &http.Server{
 			Handler: mux,
 		}
diff --git a/providers/alibabacloud/eci.go b/providers/alibabacloud/eci.go
index 8c7883541..af919a178 100644
--- a/providers/alibabacloud/eci.go
+++ b/providers/alibabacloud/eci.go
@@ -20,8 +20,8 @@ import (
 	"github.com/cpuguy83/strongerrors"
 	"github.com/virtual-kubelet/virtual-kubelet/log"
 	"github.com/virtual-kubelet/virtual-kubelet/manager"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
 	"github.com/virtual-kubelet/virtual-kubelet/providers/alibabacloud/eci"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	v1 "k8s.io/api/core/v1"
 	k8serr "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/resource"
@@ -279,7 +279,7 @@ func (p *ECIProvider) GetPod(ctx context.Context, namespace, name string) (*v1.P
 }
 
 // GetContainerLogs returns the logs of a pod by name that is running inside ECI.
-func (p *ECIProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts providers.ContainerLogOpts) (io.ReadCloser, error) {
+func (p *ECIProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts api.ContainerLogOpts) (io.ReadCloser, error) {
 	eciId := ""
 	for _, cg := range p.GetCgs() {
 		if getECITagValue(&cg, "PodName") == podName && getECITagValue(&cg, "NameSpace") == namespace {
@@ -321,7 +321,7 @@ func (p *ECIProvider) GetPodFullName(namespace string, pod string) string {
 
 // RunInContainer executes a command in a container in the pod, copying data
 // between in/out/err and the container's stdin/stdout/stderr.
-func (p *ECIProvider) RunInContainer(ctx context.Context, namespace, podName, containerName string, cmd []string, attach providers.AttachIO) error {
+func (p *ECIProvider) RunInContainer(ctx context.Context, namespace, podName, containerName string, cmd []string, attach api.AttachIO) error {
 	return nil
 }
 
diff --git a/providers/aws/fargate/cluster.go b/providers/aws/fargate/cluster.go
index d1466b2c5..57f27e642 100644
--- a/providers/aws/fargate/cluster.go
+++ b/providers/aws/fargate/cluster.go
@@ -13,7 +13,7 @@ import (
 	"github.com/aws/aws-sdk-go/service/cloudwatchlogs"
 	"github.com/aws/aws-sdk-go/service/ecs"
 	"github.com/cpuguy83/strongerrors"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	k8sTypes "k8s.io/apimachinery/pkg/types"
 )
 
@@ -313,7 +313,7 @@ func (c *Cluster) RemovePod(tag string) {
 }
 
 // GetContainerLogs returns the logs of a container from this cluster.
-func (c *Cluster) GetContainerLogs(namespace, podName, containerName string, opts providers.ContainerLogOpts) (io.ReadCloser, error) {
+func (c *Cluster) GetContainerLogs(namespace, podName, containerName string, opts api.ContainerLogOpts) (io.ReadCloser, error) {
 	if c.cloudWatchLogGroupName == "" {
 		return nil, fmt.Errorf("logs not configured, please specify a \"CloudWatchLogGroupName\"")
 	}
diff --git a/providers/aws/provider.go b/providers/aws/provider.go
index 4122d4b51..accfcc360 100644
--- a/providers/aws/provider.go
+++ b/providers/aws/provider.go
@@ -8,8 +8,8 @@ import (
 	"time"
 
 	"github.com/virtual-kubelet/virtual-kubelet/manager"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
 	"github.com/virtual-kubelet/virtual-kubelet/providers/aws/fargate"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -172,7 +172,7 @@ func (p *FargateProvider) GetPod(ctx context.Context, namespace, name string) (*
 }
 
 // GetContainerLogs retrieves the logs of a container by name from the provider.
-func (p *FargateProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts providers.ContainerLogOpts) (io.ReadCloser, error) {
+func (p *FargateProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts api.ContainerLogOpts) (io.ReadCloser, error) {
 	log.Printf("Received GetContainerLogs request for %s/%s/%s.\n", namespace, podName, containerName)
 	return p.cluster.GetContainerLogs(namespace, podName, containerName, opts)
 }
@@ -184,7 +184,7 @@ func (p *FargateProvider) GetPodFullName(namespace string, pod string) string {
 
 // RunInContainer executes a command in a container in the pod, copying data
 // between in/out/err and the container's stdin/stdout/stderr.
-func (p *FargateProvider) RunInContainer(ctx context.Context, namespace, podName, containerName string, cmd []string, attach providers.AttachIO) error {
+func (p *FargateProvider) RunInContainer(ctx context.Context, namespace, podName, containerName string, cmd []string, attach api.AttachIO) error {
 	return errNotImplemented
 }
 
diff --git a/providers/aws/provider_test.go b/providers/aws/provider_test.go
index bcc9abf28..03b0efe81 100644
--- a/providers/aws/provider_test.go
+++ b/providers/aws/provider_test.go
@@ -15,8 +15,8 @@ import (
 	"github.com/aws/aws-sdk-go/service/ec2"
 	"github.com/aws/aws-sdk-go/service/ecs"
 	"github.com/aws/aws-sdk-go/service/iam"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
 	vkAWS "github.com/virtual-kubelet/virtual-kubelet/providers/aws"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -283,7 +283,7 @@ func TestAWSFargateProviderPodLifecycle(t *testing.T) {
 		// Wait a few seconds for the logs to settle.
 		time.Sleep(10 * time.Second)
 
-		logs, err := provider.GetContainerLogs(context.Background(), "default", podName, "echo-container", providers.ContainerLogOpts{Tail: 100})
+		logs, err := provider.GetContainerLogs(context.Background(), "default", podName, "echo-container", api.ContainerLogOpts{Tail: 100})
 		if err != nil {
 			t.Fatal(err)
 		}
diff --git a/providers/azure/aci.go b/providers/azure/aci.go
index c1d23efb7..bb0b9a32c 100644
--- a/providers/azure/aci.go
+++ b/providers/azure/aci.go
@@ -26,8 +26,8 @@ import (
 	"github.com/virtual-kubelet/azure-aci/client/network"
 	"github.com/virtual-kubelet/virtual-kubelet/log"
 	"github.com/virtual-kubelet/virtual-kubelet/manager"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
 	"github.com/virtual-kubelet/virtual-kubelet/trace"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	v1 "k8s.io/api/core/v1"
 	k8serr "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/resource"
@@ -766,7 +766,7 @@ func (p *ACIProvider) GetPod(ctx context.Context, namespace, name string) (*v1.P
 }
 
 // GetContainerLogs returns the logs of a pod by name that is running inside ACI.
-func (p *ACIProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts providers.ContainerLogOpts) (io.ReadCloser, error) {
+func (p *ACIProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts api.ContainerLogOpts) (io.ReadCloser, error) {
 	ctx, span := trace.StartSpan(ctx, "aci.GetContainerLogs")
 	defer span.End()
 	ctx = addAzureAttributes(ctx, span, p)
@@ -804,7 +804,7 @@ func (p *ACIProvider) GetPodFullName(namespace string, pod string) string {
 
 // RunInContainer executes a command in a container in the pod, copying data
 // between in/out/err and the container's stdin/stdout/stderr.
-func (p *ACIProvider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach providers.AttachIO) error {
+func (p *ACIProvider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach api.AttachIO) error {
 	out := attach.Stdout()
 	if out != nil {
 		defer out.Close()
@@ -816,7 +816,7 @@ func (p *ACIProvider) RunInContainer(ctx context.Context, namespace, name, conta
 	}
 
 	// Set default terminal size
-	size := providers.TermSize{
+	size := api.TermSize{
 		Height: 60,
 		Width:  120,
 	}
diff --git a/providers/azurebatch/batch.go b/providers/azurebatch/batch.go
index 8347b8410..0f8bffd92 100644
--- a/providers/azurebatch/batch.go
+++ b/providers/azurebatch/batch.go
@@ -17,8 +17,8 @@ import (
 	"github.com/Azure/go-autorest/autorest/to"
 	"github.com/lawrencegripper/pod2docker"
 	"github.com/virtual-kubelet/virtual-kubelet/manager"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
 	azureCreds "github.com/virtual-kubelet/virtual-kubelet/providers/azure"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -260,7 +260,7 @@ const (
 )
 
 // GetContainerLogs returns the logs of a container running in a pod by name.
-func (p *Provider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts providers.ContainerLogOpts) (io.ReadCloser, error) {
+func (p *Provider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts api.ContainerLogOpts) (io.ReadCloser, error) {
 	log.Println("Getting pod logs ....")
 
 	taskID := getTaskIDForPod(namespace, podName)
@@ -319,7 +319,7 @@ func (p *Provider) GetPodFullName(namespace string, pod string) string {
 // RunInContainer executes a command in a container in the pod, copying data
 // between in/out/err and the container's stdin/stdout/stderr.
 // TODO: Implementation
-func (p *Provider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach providers.AttachIO) error {
+func (p *Provider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach api.AttachIO) error {
 	log.Printf("receive ExecInContainer %q\n", container)
 	return nil
 }
diff --git a/providers/azurebatch/batch_test.go b/providers/azurebatch/batch_test.go
index 438acb04e..dc7b9dd6c 100644
--- a/providers/azurebatch/batch_test.go
+++ b/providers/azurebatch/batch_test.go
@@ -12,7 +12,7 @@ import (
 
 	"github.com/Azure/azure-sdk-for-go/services/batch/2017-09-01.6.0/batch"
 	"github.com/Azure/go-autorest/autorest"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 
 	apiv1 "k8s.io/api/core/v1"
 )
@@ -121,7 +121,7 @@ func Test_readLogs_404Response_expectReturnStartupLogs(t *testing.T) {
 		return batch.ReadCloser{}, fmt.Errorf("Failed in test mock of getFileFromTask")
 	}
 
-	logs, err := provider.GetContainerLogs(context.Background(), pod.Namespace, pod.Name, containerName, providers.ContainerLogOpts{})
+	logs, err := provider.GetContainerLogs(context.Background(), pod.Namespace, pod.Name, containerName, api.ContainerLogOpts{})
 	if err != nil {
 		t.Fatalf("GetContainerLogs return error: %v", err)
 	}
@@ -161,7 +161,7 @@ func Test_readLogs_JsonResponse_expectFormattedLogs(t *testing.T) {
 		return batch.ReadCloser{}, fmt.Errorf("Failed in test mock of getFileFromTask")
 	}
 
-	logs, err := provider.GetContainerLogs(context.Background(), pod.Namespace, pod.Name, containerName, providers.ContainerLogOpts{})
+	logs, err := provider.GetContainerLogs(context.Background(), pod.Namespace, pod.Name, containerName, api.ContainerLogOpts{})
 	if err != nil {
 		t.Errorf("GetContainerLogs return error: %v", err)
 	}
diff --git a/providers/cri/cri.go b/providers/cri/cri.go
index 85f7682fb..e89b252f8 100644
--- a/providers/cri/cri.go
+++ b/providers/cri/cri.go
@@ -20,6 +20,7 @@ import (
 	log "github.com/sirupsen/logrus"
 	"github.com/virtual-kubelet/virtual-kubelet/manager"
 	"github.com/virtual-kubelet/virtual-kubelet/providers"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	"google.golang.org/grpc"
 	v1 "k8s.io/api/core/v1"
 	k8serr "k8s.io/apimachinery/pkg/api/errors"
@@ -607,7 +608,7 @@ func (p *CRIProvider) GetPod(ctx context.Context, namespace, name string) (*v1.P
 }
 
 // Reads a log file into a string
-func readLogFile(filename string, opts providers.ContainerLogOpts) (io.ReadCloser, error) {
+func readLogFile(filename string, opts api.ContainerLogOpts) (io.ReadCloser, error) {
 	file, err := os.Open(filename)
 	if err != nil {
 		return nil, err
@@ -627,7 +628,7 @@ func readLogFile(filename string, opts providers.ContainerLogOpts) (io.ReadClose
 }
 
 // Provider function to read the logs of a container
-func (p *CRIProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts providers.ContainerLogOpts) (io.ReadCloser, error) {
+func (p *CRIProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts api.ContainerLogOpts) (io.ReadCloser, error) {
 	log.Printf("receive GetContainerLogs %q", containerName)
 
 	err := p.refreshNodeState()
@@ -656,7 +657,7 @@ func (p *CRIProvider) GetPodFullName(namespace string, pod string) string {
 // RunInContainer executes a command in a container in the pod, copying data
 // between in/out/err and the container's stdin/stdout/stderr.
 // TODO: Implementation
-func (p *CRIProvider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach providers.AttachIO) error {
+func (p *CRIProvider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach api.AttachIO) error {
 	log.Printf("receive ExecInContainer %q\n", container)
 	return nil
 }
diff --git a/providers/huawei/cci.go b/providers/huawei/cci.go
index 2a7d17946..941d6496a 100644
--- a/providers/huawei/cci.go
+++ b/providers/huawei/cci.go
@@ -17,8 +17,8 @@ import (
 
 	"github.com/cpuguy83/strongerrors"
 	"github.com/virtual-kubelet/virtual-kubelet/manager"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
 	"github.com/virtual-kubelet/virtual-kubelet/providers/huawei/auth"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -299,7 +299,7 @@ func (p *CCIProvider) GetPod(ctx context.Context, namespace, name string) (*v1.P
 }
 
 // GetContainerLogs retrieves the logs of a container by name from the huawei CCI provider.
-func (p *CCIProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts providers.ContainerLogOpts) (io.ReadCloser, error) {
+func (p *CCIProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts api.ContainerLogOpts) (io.ReadCloser, error) {
 	return ioutil.NopCloser(strings.NewReader("")), nil
 }
 
@@ -312,7 +312,7 @@ func (p *CCIProvider) GetPodFullName(namespace string, pod string) string {
 // RunInContainer executes a command in a container in the pod, copying data
 // between in/out/err and the container's stdin/stdout/stderr.
 // TODO: Implementation
-func (p *CCIProvider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach providers.AttachIO) error {
+func (p *CCIProvider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach api.AttachIO) error {
 	log.Printf("receive ExecInContainer %q\n", container)
 	return nil
 }
diff --git a/providers/mock/mock.go b/providers/mock/mock.go
index 900730cd9..67ee94547 100644
--- a/providers/mock/mock.go
+++ b/providers/mock/mock.go
@@ -14,12 +14,11 @@ import (
 	"github.com/cpuguy83/strongerrors/status/ocstatus"
 	"github.com/virtual-kubelet/virtual-kubelet/log"
 	"github.com/virtual-kubelet/virtual-kubelet/trace"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	stats "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
-
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
 )
 
 const (
@@ -223,7 +222,7 @@ func (p *MockProvider) GetPod(ctx context.Context, namespace, name string) (pod
 }
 
 // GetContainerLogs retrieves the logs of a container by name from the provider.
-func (p *MockProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts providers.ContainerLogOpts) (io.ReadCloser, error) {
+func (p *MockProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts api.ContainerLogOpts) (io.ReadCloser, error) {
 	ctx, span := trace.StartSpan(ctx, "GetContainerLogs")
 	defer span.End()
 
@@ -242,7 +241,7 @@ func (p *MockProvider) GetPodFullName(namespace string, pod string) string {
 
 // RunInContainer executes a command in a container in the pod, copying data
 // between in/out/err and the container's stdin/stdout/stderr.
-func (p *MockProvider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach providers.AttachIO) error {
+func (p *MockProvider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach api.AttachIO) error {
 	log.G(context.TODO()).Infof("receive ExecInContainer %q", container)
 	return nil
 }
@@ -413,7 +412,7 @@ func (p *MockProvider) NodeDaemonEndpoints(ctx context.Context) *v1.NodeDaemonEn
 // OperatingSystem returns the operating system for this provider.
 // This is a noop to default to Linux for now.
 func (p *MockProvider) OperatingSystem() string {
-	return providers.OperatingSystemLinux
+	return "Linux"
 }
 
 // GetStatsSummary returns dummy stats for all pods known by this provider.
diff --git a/providers/node.go b/providers/node.go
deleted file mode 100644
index 343840f42..000000000
--- a/providers/node.go
+++ /dev/null
@@ -1,28 +0,0 @@
-package providers
-
-import (
-	"context"
-
-	v1 "k8s.io/api/core/v1"
-)
-
-// NodeProvider is the interface used for registering a node and updating its
-// status in Kubernetes.
-//
-// Note: Implementers can choose to manage a node themselves, in which case
-// it is not needed to provide an implementation for this interface.
-type NodeProvider interface {
-	// Ping checks if the node is still active.
-	// This is intended to be lightweight as it will be called periodically as a
-	// heartbeat to keep the node marked as ready in Kubernetes.
-	Ping(context.Context) error
-
-	// NotifyNodeStatus is used to asynchronously monitor the node.
-	// The passed in callback should be called any time there is a change to the
-	// node's status.
-	// This will generally trigger a call to the Kubernetes API server to update
-	// the status.
-	//
-	// NotifyNodeStatus should not block callers.
-	NotifyNodeStatus(ctx context.Context, cb func(*v1.Node))
-}
diff --git a/providers/nomad/nomad.go b/providers/nomad/nomad.go
index ad13564dc..60ce9d8ca 100644
--- a/providers/nomad/nomad.go
+++ b/providers/nomad/nomad.go
@@ -12,6 +12,7 @@ import (
 	nomad "github.com/hashicorp/nomad/api"
 	"github.com/virtual-kubelet/virtual-kubelet/manager"
 	"github.com/virtual-kubelet/virtual-kubelet/providers"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -147,7 +148,7 @@ func (p *Provider) GetPod(ctx context.Context, namespace, name string) (pod *v1.
 }
 
 // GetContainerLogs retrieves the logs of a container by name from the provider.
-func (p *Provider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts providers.ContainerLogOpts) (io.ReadCloser, error) {
+func (p *Provider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts api.ContainerLogOpts) (io.ReadCloser, error) {
 	return ioutil.NopCloser(strings.NewReader("")), nil
 }
 
@@ -159,7 +160,7 @@ func (p *Provider) GetPodFullName(ctx context.Context, namespace string, pod str
 // RunInContainer executes a command in a container in the pod, copying data
 // between in/out/err and the container's stdin/stdout/stderr.
 // TODO: Implementation
-func (p *Provider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach providers.AttachIO) error {
+func (p *Provider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach api.AttachIO) error {
 	log.Printf("ExecInContainer %q\n", container)
 	return nil
 }
diff --git a/providers/openstack/zun.go b/providers/openstack/zun.go
index 81b34ecad..29debbc78 100644
--- a/providers/openstack/zun.go
+++ b/providers/openstack/zun.go
@@ -18,6 +18,7 @@ import (
 	"github.com/gophercloud/gophercloud/pagination"
 	"github.com/virtual-kubelet/virtual-kubelet/manager"
 	"github.com/virtual-kubelet/virtual-kubelet/providers"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -215,7 +216,7 @@ func (p *ZunProvider) getContainers(ctx context.Context, pod *v1.Pod) ([]Contain
 
 // RunInContainer executes a command in a container in the pod, copying data
 // between in/out/err and the container's stdin/stdout/stderr.
-func (p *ZunProvider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach providers.AttachIO) error {
+func (p *ZunProvider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach api.AttachIO) error {
 	log.Printf("receive ExecInContainer %q\n", container)
 	return nil
 }
@@ -235,7 +236,7 @@ func (p *ZunProvider) GetPodStatus(ctx context.Context, namespace, name string)
 	return &pod.Status, nil
 }
 
-func (p *ZunProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts providers.ContainerLogOpts) (io.ReadCloser, error) {
+func (p *ZunProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts api.ContainerLogOpts) (io.ReadCloser, error) {
 	return ioutil.NopCloser(strings.NewReader("not support in Zun Provider")), nil
 }
 
diff --git a/providers/provider.go b/providers/provider.go
index 81b322d4c..36fcf2afc 100644
--- a/providers/provider.go
+++ b/providers/provider.go
@@ -3,38 +3,23 @@ package providers
 import (
 	"context"
 	"io"
-	"time"
 
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	v1 "k8s.io/api/core/v1"
 	stats "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
 )
 
 // Provider contains the methods required to implement a virtual-kubelet provider.
 type Provider interface {
-	// CreatePod takes a Kubernetes Pod and deploys it within the provider.
-	CreatePod(ctx context.Context, pod *v1.Pod) error
-
-	// UpdatePod takes a Kubernetes Pod and updates it within the provider.
-	UpdatePod(ctx context.Context, pod *v1.Pod) error
-
-	// DeletePod takes a Kubernetes Pod and deletes it from the provider.
-	DeletePod(ctx context.Context, pod *v1.Pod) error
-
-	// GetPod retrieves a pod by name from the provider (can be cached).
-	GetPod(ctx context.Context, namespace, name string) (*v1.Pod, error)
+	vkubelet.PodLifecycleHandler
 
 	// GetContainerLogs retrieves the logs of a container by name from the provider.
-	GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts ContainerLogOpts) (io.ReadCloser, error)
+	GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts api.ContainerLogOpts) (io.ReadCloser, error)
 
 	// RunInContainer executes a command in a container in the pod, copying data
 	// between in/out/err and the container's stdin/stdout/stderr.
-	RunInContainer(ctx context.Context, namespace, podName, containerName string, cmd []string, attach AttachIO) error
-
-	// GetPodStatus retrieves the status of a pod by name from the provider.
-	GetPodStatus(ctx context.Context, namespace, name string) (*v1.PodStatus, error)
-
-	// GetPods retrieves a list of all pods running on the provider (can be cached).
-	GetPods(context.Context) ([]*v1.Pod, error)
+	RunInContainer(ctx context.Context, namespace, podName, containerName string, cmd []string, attach api.AttachIO) error
 
 	// Capacity returns a resource list with the capacity constraints of the provider.
 	Capacity(context.Context) v1.ResourceList
@@ -55,42 +40,7 @@ type Provider interface {
 	OperatingSystem() string
 }
 
-// ContainerLogOpts are used to pass along options to be set on the container
-// log stream.
-type ContainerLogOpts struct {
-	Tail       int
-	Since      time.Duration
-	LimitBytes int
-	Timestamps bool
-}
-
 // PodMetricsProvider is an optional interface that providers can implement to expose pod stats
 type PodMetricsProvider interface {
 	GetStatsSummary(context.Context) (*stats.Summary, error)
 }
-
-// PodNotifier notifies callers of pod changes.
-// Providers should implement this interface to enable callers to be notified
-// of pod status updates asyncronously.
-type PodNotifier interface {
-	// NotifyPods instructs the notifier to call the passed in function when
-	// the pod status changes.
-	//
-	// NotifyPods should not block callers.
-	NotifyPods(context.Context, func(*v1.Pod))
-}
-
-// AttachIO is used to pass in streams to attach to a container process
-type AttachIO interface {
-	Stdin() io.Reader
-	Stdout() io.WriteCloser
-	Stderr() io.WriteCloser
-	TTY() bool
-	Resize() <-chan TermSize
-}
-
-// TermSize is used to set the terminal size from attached clients.
-type TermSize struct {
-	Width  uint16
-	Height uint16
-}
diff --git a/providers/web/broker.go b/providers/web/broker.go
index e6d5ee411..9587f2351 100644
--- a/providers/web/broker.go
+++ b/providers/web/broker.go
@@ -30,7 +30,7 @@ import (
 
 	"github.com/cenkalti/backoff"
 	"github.com/cpuguy83/strongerrors"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
+	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	v1 "k8s.io/api/core/v1"
 )
 
@@ -109,7 +109,7 @@ func (p *BrokerProvider) GetPod(ctx context.Context, namespace, name string) (*v
 }
 
 // GetContainerLogs returns the logs of a container running in a pod by name.
-func (p *BrokerProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts providers.ContainerLogOpts) (io.ReadCloser, error) {
+func (p *BrokerProvider) GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts api.ContainerLogOpts) (io.ReadCloser, error) {
 	urlPathStr := fmt.Sprintf(
 		"/getContainerLogs?namespace=%s&podName=%s&containerName=%s&tail=%d",
 		url.QueryEscape(namespace),
@@ -134,7 +134,7 @@ func (p *BrokerProvider) GetPodFullName(namespace string, pod string) string {
 // RunInContainer executes a command in a container in the pod, copying data
 // between in/out/err and the container's stdin/stdout/stderr.
 // TODO: Implementation
-func (p *BrokerProvider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach providers.AttachIO) error {
+func (p *BrokerProvider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach api.AttachIO) error {
 	log.Printf("receive ExecInContainer %q\n", container)
 	return nil
 }
diff --git a/vkubelet/api/exec.go b/vkubelet/api/exec.go
index 021e330bf..ebbacd9ae 100644
--- a/vkubelet/api/exec.go
+++ b/vkubelet/api/exec.go
@@ -10,21 +10,38 @@ import (
 	"github.com/cpuguy83/strongerrors"
 	"github.com/gorilla/mux"
 	"github.com/pkg/errors"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
 	"k8s.io/apimachinery/pkg/types"
 	remoteutils "k8s.io/client-go/tools/remotecommand"
 	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/kubelet/server/remotecommand"
 )
 
-type ExecBackend interface {
-	RunInContainer(ctx context.Context, namespace, podName, containerName string, cmd []string, attach providers.AttachIO) error
+// ContainerExecHandlerFunc defines the handler function used for "execing" into a
+// container in a pod.
+type ContainerExecHandlerFunc func(ctx context.Context, namespace, podName, containerName string, cmd []string, attach AttachIO) error
+
+// AttachIO is used to pass in streams to attach to a container process
+type AttachIO interface {
+	Stdin() io.Reader
+	Stdout() io.WriteCloser
+	Stderr() io.WriteCloser
+	TTY() bool
+	Resize() <-chan TermSize
 }
 
-// PodExecHandlerFunc makes an http handler func from a Provider which execs a command in a pod's container
+// TermSize is used to set the terminal size from attached clients.
+type TermSize struct {
+	Width  uint16
+	Height uint16
+}
+
+// HandleContainerExec makes an http handler func from a Provider which execs a command in a pod's container
 // Note that this handler currently depends on gorrilla/mux to get url parts as variables.
 // TODO(@cpuguy83): don't force gorilla/mux on consumers of this function
-func PodExecHandlerFunc(backend ExecBackend) http.HandlerFunc {
+func HandleContainerExec(h ContainerExecHandlerFunc) http.HandlerFunc {
+	if h == nil {
+		return NotImplemented
+	}
 	return handleError(func(w http.ResponseWriter, req *http.Request) error {
 		vars := mux.Vars(req)
 
@@ -48,7 +65,7 @@ func PodExecHandlerFunc(backend ExecBackend) http.HandlerFunc {
 		ctx, cancel := context.WithCancel(context.TODO())
 		defer cancel()
 
-		exec := &containerExecContext{ctx: ctx, b: backend, pod: pod, namespace: namespace, container: container}
+		exec := &containerExecContext{ctx: ctx, h: h, pod: pod, namespace: namespace, container: container}
 		remotecommand.ServeExec(w, req, exec, "", "", container, command, streamOpts, idleTimeout, streamCreationTimeout, supportedStreamProtocols)
 
 		return nil
@@ -77,7 +94,7 @@ func getExecOptions(req *http.Request) (*remotecommand.Options, error) {
 }
 
 type containerExecContext struct {
-	b                         ExecBackend
+	h                         ContainerExecHandlerFunc
 	eio                       *execIO
 	namespace, pod, container string
 	ctx                       context.Context
@@ -95,7 +112,7 @@ func (c *containerExecContext) ExecInContainer(name string, uid types.UID, conta
 	}
 
 	if tty {
-		eio.chResize = make(chan providers.TermSize)
+		eio.chResize = make(chan TermSize)
 	}
 
 	ctx, cancel := context.WithCancel(c.ctx)
@@ -105,7 +122,7 @@ func (c *containerExecContext) ExecInContainer(name string, uid types.UID, conta
 		go func() {
 			send := func(s remoteutils.TerminalSize) bool {
 				select {
-				case eio.chResize <- providers.TermSize{Width: s.Width, Height: s.Height}:
+				case eio.chResize <- TermSize{Width: s.Width, Height: s.Height}:
 					return false
 				case <-ctx.Done():
 					return true
@@ -125,7 +142,7 @@ func (c *containerExecContext) ExecInContainer(name string, uid types.UID, conta
 		}()
 	}
 
-	return c.b.RunInContainer(c.ctx, c.namespace, c.pod, c.container, cmd, eio)
+	return c.h(c.ctx, c.namespace, c.pod, c.container, cmd, eio)
 }
 
 type execIO struct {
@@ -133,7 +150,7 @@ type execIO struct {
 	stdin    io.Reader
 	stdout   io.WriteCloser
 	stderr   io.WriteCloser
-	chResize chan providers.TermSize
+	chResize chan TermSize
 }
 
 func (e *execIO) TTY() bool {
@@ -152,6 +169,6 @@ func (e *execIO) Stderr() io.WriteCloser {
 	return e.stderr
 }
 
-func (e *execIO) Resize() <-chan providers.TermSize {
+func (e *execIO) Resize() <-chan TermSize {
 	return e.chResize
 }
diff --git a/vkubelet/api/logs.go b/vkubelet/api/logs.go
index 7689f3373..d062c98e2 100644
--- a/vkubelet/api/logs.go
+++ b/vkubelet/api/logs.go
@@ -5,21 +5,31 @@ import (
 	"io"
 	"net/http"
 	"strconv"
+	"time"
 
 	"github.com/cpuguy83/strongerrors"
 	"github.com/gorilla/mux"
 	"github.com/pkg/errors"
 	"github.com/virtual-kubelet/virtual-kubelet/log"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
 )
 
-// ContainerLogsBackend is used in place of backend implementations for getting container logs
-type ContainerLogsBackend interface {
-	GetContainerLogs(ctx context.Context, namespace, podName, containerName string, opts providers.ContainerLogOpts) (io.ReadCloser, error)
+// ContainerLogsHandlerFunc is used in place of backend implementations for getting container logs
+type ContainerLogsHandlerFunc func(ctx context.Context, namespace, podName, containerName string, opts ContainerLogOpts) (io.ReadCloser, error)
+
+// ContainerLogOpts are used to pass along options to be set on the container
+// log stream.
+type ContainerLogOpts struct {
+	Tail       int
+	Since      time.Duration
+	LimitBytes int
+	Timestamps bool
 }
 
-// PodLogsHandlerFunc creates an http handler function from a provider to serve logs from a pod
-func PodLogsHandlerFunc(p ContainerLogsBackend) http.HandlerFunc {
+// HandleContainerLogs creates an http handler function from a provider to serve logs from a pod
+func HandleContainerLogs(h ContainerLogsHandlerFunc) http.HandlerFunc {
+	if h == nil {
+		return NotImplemented
+	}
 	return handleError(func(w http.ResponseWriter, req *http.Request) error {
 		vars := mux.Vars(req)
 		if len(vars) != 3 {
@@ -45,11 +55,11 @@ func PodLogsHandlerFunc(p ContainerLogsBackend) http.HandlerFunc {
 		// TODO(@cpuguy83): support v1.PodLogOptions
 		// The kubelet decoding here is not straight forward, so this needs to be disected
 
-		opts := providers.ContainerLogOpts{
+		opts := ContainerLogOpts{
 			Tail: tail,
 		}
 
-		logs, err := p.GetContainerLogs(ctx, namespace, pod, container, opts)
+		logs, err := h(ctx, namespace, pod, container, opts)
 		if err != nil {
 			return errors.Wrap(err, "error getting container logs?)")
 		}
diff --git a/vkubelet/api/pods.go b/vkubelet/api/pods.go
index 6d7600128..e0dc3376a 100644
--- a/vkubelet/api/pods.go
+++ b/vkubelet/api/pods.go
@@ -6,18 +6,14 @@ import (
 
 	"github.com/cpuguy83/strongerrors"
 	"github.com/virtual-kubelet/virtual-kubelet/log"
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/serializer"
 )
 
-// ContainerLogsBackend is used in place of backend implementations for the provider's pods
-type RunningPodsBackend interface {
-	// GetPods retrieves a list of all pods running on the provider (can be cached).
-	GetPods(context.Context) ([]*v1.Pod, error)
-}
+type PodListerFunc func(context.Context) ([]*v1.Pod, error)
 
-func RunningPodsHandlerFunc(p RunningPodsBackend) http.HandlerFunc {
+func HandleRunningPods(getPods PodListerFunc) http.HandlerFunc {
 	scheme := runtime.NewScheme()
 	v1.SchemeBuilder.AddToScheme(scheme)
 	codecs := serializer.NewCodecFactory(scheme)
@@ -25,7 +21,7 @@ func RunningPodsHandlerFunc(p RunningPodsBackend) http.HandlerFunc {
 	return handleError(func(w http.ResponseWriter, req *http.Request) error {
 		ctx := req.Context()
 		ctx = log.WithLogger(ctx, log.L)
-		pods, err := p.GetPods(ctx)
+		pods, err := getPods(ctx)
 		if err != nil {
 			return err
 		}
diff --git a/vkubelet/apiserver.go b/vkubelet/api/server.go
similarity index 64%
rename from vkubelet/apiserver.go
rename to vkubelet/api/server.go
index b5b8b824a..42997ca74 100644
--- a/vkubelet/apiserver.go
+++ b/vkubelet/api/server.go
@@ -1,12 +1,10 @@
-package vkubelet
+package api
 
 import (
 	"net/http"
 
 	"github.com/gorilla/mux"
 	"github.com/virtual-kubelet/virtual-kubelet/log"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
-	"github.com/virtual-kubelet/virtual-kubelet/vkubelet/api"
 	"go.opencensus.io/plugin/ochttp"
 	"go.opencensus.io/plugin/ochttp/propagation/b3"
 )
@@ -20,37 +18,40 @@ type ServeMux interface {
 	Handle(path string, h http.Handler)
 }
 
+type PodHandlerConfig struct {
+	RunInContainer   ContainerExecHandlerFunc
+	GetContainerLogs ContainerLogsHandlerFunc
+	GetPods          PodListerFunc
+}
+
 // PodHandler creates an http handler for interacting with pods/containers.
-func PodHandler(p providers.Provider, debug bool) http.Handler {
+func PodHandler(p PodHandlerConfig, debug bool) http.Handler {
 	r := mux.NewRouter()
 
 	// This matches the behaviour in the reference kubelet
 	r.StrictSlash(true)
 	if debug {
-		r.HandleFunc("/runningpods/", api.RunningPodsHandlerFunc(p)).Methods("GET")
+		r.HandleFunc("/runningpods/", HandleRunningPods(p.GetPods)).Methods("GET")
 	}
-	r.HandleFunc("/containerLogs/{namespace}/{pod}/{container}", api.PodLogsHandlerFunc(p)).Methods("GET")
-	r.HandleFunc("/exec/{namespace}/{pod}/{container}", api.PodExecHandlerFunc(p)).Methods("POST")
+	r.HandleFunc("/containerLogs/{namespace}/{pod}/{container}", HandleContainerLogs(p.GetContainerLogs)).Methods("GET")
+	r.HandleFunc("/exec/{namespace}/{pod}/{container}", HandleContainerExec(p.RunInContainer)).Methods("POST")
 	r.NotFoundHandler = http.HandlerFunc(NotFound)
 	return r
 }
 
-// MetricsSummaryHandler creates an http handler for serving pod metrics.
+// PodStatsSummaryHandler creates an http handler for serving pod metrics.
 //
-// If the passed in provider does not implement providers.PodMetricsProvider,
-// it will create handlers that just serves http.StatusNotImplemented
-func MetricsSummaryHandler(p providers.Provider) http.Handler {
+// If the passed in handler func is nil this will create handlers which only
+//  serves http.StatusNotImplemented
+func PodStatsSummaryHandler(f PodStatsSummaryHandlerFunc) http.Handler {
+	if f == nil {
+		return http.HandlerFunc(NotImplemented)
+	}
+
 	r := mux.NewRouter()
 
 	const summaryRoute = "/stats/summary"
-	var h http.HandlerFunc
-
-	mp, ok := p.(providers.PodMetricsProvider)
-	if !ok {
-		h = NotImplemented
-	} else {
-		h = api.PodMetricsHandlerFunc(mp)
-	}
+	h := HandlePodStatsSummary(f)
 
 	r.Handle(summaryRoute, ochttp.WithRouteTag(h, "PodStatsSummaryHandler")).Methods("GET")
 	r.Handle(summaryRoute+"/", ochttp.WithRouteTag(h, "PodStatsSummaryHandler")).Methods("GET")
@@ -63,16 +64,25 @@ func MetricsSummaryHandler(p providers.Provider) http.Handler {
 //
 // Callers should take care to namespace the serve mux as they see fit, however
 // these routes get called by the Kubernetes API server.
-func AttachPodRoutes(p providers.Provider, mux ServeMux, debug bool) {
+func AttachPodRoutes(p PodHandlerConfig, mux ServeMux, debug bool) {
 	mux.Handle("/", InstrumentHandler(PodHandler(p, debug)))
 }
 
-// AttachMetricsRoutes adds the http routes for pod/node metrics to the passed in serve mux.
+// PodMetricsConfig stores the handlers for pod metrics routes
+// It is used by AttachPodMetrics.
+//
+// The main reason for this struct is in case of expansion we do not need to break
+// the package level API.
+type PodMetricsConfig struct {
+	GetStatsSummary PodStatsSummaryHandlerFunc
+}
+
+// AttachPodMetricsRoutes adds the http routes for pod/node metrics to the passed in serve mux.
 //
 // Callers should take care to namespace the serve mux as they see fit, however
 // these routes get called by the Kubernetes API server.
-func AttachMetricsRoutes(p providers.Provider, mux ServeMux) {
-	mux.Handle("/", InstrumentHandler(MetricsSummaryHandler(p)))
+func AttachPodMetricsRoutes(p PodMetricsConfig, mux ServeMux) {
+	mux.Handle("/", InstrumentHandler(HandlePodStatsSummary(p.GetStatsSummary)))
 }
 
 func instrumentRequest(r *http.Request) *http.Request {
diff --git a/vkubelet/api/stats.go b/vkubelet/api/stats.go
index afa7b23a7..444e26b21 100644
--- a/vkubelet/api/stats.go
+++ b/vkubelet/api/stats.go
@@ -10,15 +10,16 @@ import (
 	stats "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
 )
 
-// PodMetricsBackend is used in place of backend implementations to get k8s pod metrics.
-type PodMetricsBackend interface {
-	GetStatsSummary(context.Context) (*stats.Summary, error)
-}
+// PodStatsSummaryHandlerFunc defines the handler for getting pod stats summaries
+type PodStatsSummaryHandlerFunc func(context.Context) (*stats.Summary, error)
 
-// PodMetricsHandlerFunc makes an HTTP handler for implementing the kubelet summary stats endpoint
-func PodMetricsHandlerFunc(b PodMetricsBackend) http.HandlerFunc {
+// HandlePodStatsSummary makes an HTTP handler for implementing the kubelet summary stats endpoint
+func HandlePodStatsSummary(h PodStatsSummaryHandlerFunc) http.HandlerFunc {
+	if h == nil {
+		return NotImplemented
+	}
 	return handleError(func(w http.ResponseWriter, req *http.Request) error {
-		stats, err := b.GetStatsSummary(req.Context())
+		stats, err := h(req.Context())
 		if err != nil {
 			if errors.Cause(err) == context.Canceled {
 				return strongerrors.Cancelled(err)
diff --git a/vkubelet/doc.go b/vkubelet/doc.go
index 061cf69fd..47597ba77 100644
--- a/vkubelet/doc.go
+++ b/vkubelet/doc.go
@@ -19,11 +19,11 @@ controller.
 
 Up to this point you have a running virtual kubelet controller, but no HTTP
 handlers to deal with requests forwarded from the API server for things like
-pod logs (e.g. user calls `kubectl logs myVKPod`).  This package provides some
-helpers for this: `AttachPodRoutes` and `AttachMetricsRoutes`.
+pod logs (e.g. user calls `kubectl logs myVKPod`).  The api package provides some
+helpers for this: `api.AttachPodRoutes` and `api.AttachMetricsRoutes`.
 
 	mux := http.NewServeMux()
-	vkubelet.AttachPodRoutes(provider, mux)
+	api.AttachPodRoutes(provider, mux)
 
 You must configure your own HTTP server, but these helpers will add handlers at
 the correct URI paths to your serve mux. You are not required to use go's
diff --git a/vkubelet/node.go b/vkubelet/node.go
index 8e3e17618..145315822 100644
--- a/vkubelet/node.go
+++ b/vkubelet/node.go
@@ -9,7 +9,6 @@ import (
 	"github.com/cpuguy83/strongerrors/status/ocstatus"
 	pkgerrors "github.com/pkg/errors"
 	"github.com/virtual-kubelet/virtual-kubelet/log"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
 	"github.com/virtual-kubelet/virtual-kubelet/trace"
 	coord "k8s.io/api/coordination/v1beta1"
 	corev1 "k8s.io/api/core/v1"
@@ -21,12 +20,33 @@ import (
 	v1 "k8s.io/client-go/kubernetes/typed/core/v1"
 )
 
+// NodeProvider is the interface used for registering a node and updating its
+// status in Kubernetes.
+//
+// Note: Implementers can choose to manage a node themselves, in which case
+// it is not needed to provide an implementation for this interface.
+type NodeProvider interface {
+	// Ping checks if the node is still active.
+	// This is intended to be lightweight as it will be called periodically as a
+	// heartbeat to keep the node marked as ready in Kubernetes.
+	Ping(context.Context) error
+
+	// NotifyNodeStatus is used to asynchronously monitor the node.
+	// The passed in callback should be called any time there is a change to the
+	// node's status.
+	// This will generally trigger a call to the Kubernetes API server to update
+	// the status.
+	//
+	// NotifyNodeStatus should not block callers.
+	NotifyNodeStatus(ctx context.Context, cb func(*corev1.Node))
+}
+
 // NewNode creates a new node.
 // This does not have any side-effects on the system or kubernetes.
 //
 // Use the node's `Run` method to register and run the loops to update the node
 // in Kubernetes.
-func NewNode(p providers.NodeProvider, node *corev1.Node, leases v1beta1.LeaseInterface, nodes v1.NodeInterface, opts ...NodeOpt) (*Node, error) {
+func NewNode(p NodeProvider, node *corev1.Node, leases v1beta1.LeaseInterface, nodes v1.NodeInterface, opts ...NodeOpt) (*Node, error) {
 	n := &Node{p: p, n: node, leases: leases, nodes: nodes}
 	for _, o := range opts {
 		if err := o(n); err != nil {
@@ -79,7 +99,7 @@ func WithNodeLease(l *coord.Lease) NodeOpt {
 // Node deals with creating and managing a node object in Kubernetes.
 // It can register a node with Kubernetes and periodically update its status.
 type Node struct {
-	p providers.NodeProvider
+	p NodeProvider
 	n *corev1.Node
 
 	leases v1beta1.LeaseInterface
diff --git a/vkubelet/node_test.go b/vkubelet/node_test.go
index 169a0ae0c..ddd6bf8c5 100644
--- a/vkubelet/node_test.go
+++ b/vkubelet/node_test.go
@@ -6,7 +6,6 @@ import (
 	"testing"
 	"time"
 
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
 	"gotest.tools/assert"
 	"gotest.tools/assert/cmp"
 	coord "k8s.io/api/coordination/v1beta1"
@@ -232,7 +231,7 @@ func testNode(t *testing.T) *corev1.Node {
 }
 
 type testNodeProvider struct {
-	providers.NodeProvider
+	NodeProvider
 	statusHandlers []func(*corev1.Node)
 }
 
diff --git a/vkubelet/podcontroller.go b/vkubelet/podcontroller.go
index e66385ce4..dbebcbeaa 100644
--- a/vkubelet/podcontroller.go
+++ b/vkubelet/podcontroller.go
@@ -39,6 +39,39 @@ import (
 	"github.com/virtual-kubelet/virtual-kubelet/log"
 )
 
+// PodLifecycleHandler defines the interface used by the PodController to react
+// to new and changed pods scheduled to the node that is being managed.
+type PodLifecycleHandler interface {
+	// CreatePod takes a Kubernetes Pod and deploys it within the provider.
+	CreatePod(ctx context.Context, pod *corev1.Pod) error
+
+	// UpdatePod takes a Kubernetes Pod and updates it within the provider.
+	UpdatePod(ctx context.Context, pod *corev1.Pod) error
+
+	// DeletePod takes a Kubernetes Pod and deletes it from the provider.
+	DeletePod(ctx context.Context, pod *corev1.Pod) error
+
+	// GetPod retrieves a pod by name from the provider (can be cached).
+	GetPod(ctx context.Context, namespace, name string) (*corev1.Pod, error)
+
+	// GetPodStatus retrieves the status of a pod by name from the provider.
+	GetPodStatus(ctx context.Context, namespace, name string) (*corev1.PodStatus, error)
+
+	// GetPods retrieves a list of all pods running on the provider (can be cached).
+	GetPods(context.Context) ([]*corev1.Pod, error)
+}
+
+// PodNotifier notifies callers of pod changes.
+// Providers should implement this interface to enable callers to be notified
+// of pod status updates asyncronously.
+type PodNotifier interface {
+	// NotifyPods instructs the notifier to call the passed in function when
+	// the pod status changes.
+	//
+	// NotifyPods should not block callers.
+	NotifyPods(context.Context, func(*corev1.Pod))
+}
+
 // PodController is the controller implementation for Pod resources.
 type PodController struct {
 	// server is the instance to which this controller belongs.
diff --git a/vkubelet/vkubelet.go b/vkubelet/vkubelet.go
index 1ac1731f9..2805cb7ad 100644
--- a/vkubelet/vkubelet.go
+++ b/vkubelet/vkubelet.go
@@ -6,7 +6,6 @@ import (
 	"time"
 
 	"github.com/virtual-kubelet/virtual-kubelet/manager"
-	"github.com/virtual-kubelet/virtual-kubelet/providers"
 	"github.com/virtual-kubelet/virtual-kubelet/trace"
 	corev1 "k8s.io/api/core/v1"
 	corev1informers "k8s.io/client-go/informers/core/v1"
@@ -23,7 +22,7 @@ type Server struct {
 	namespace       string
 	nodeName        string
 	k8sClient       kubernetes.Interface
-	provider        providers.Provider
+	provider        PodLifecycleHandler
 	resourceManager *manager.ResourceManager
 	podSyncWorkers  int
 	podInformer     corev1informers.PodInformer
@@ -35,7 +34,7 @@ type Config struct {
 	Client          *kubernetes.Clientset
 	Namespace       string
 	NodeName        string
-	Provider        providers.Provider
+	Provider        PodLifecycleHandler
 	ResourceManager *manager.ResourceManager
 	PodSyncWorkers  int
 	PodInformer     corev1informers.PodInformer
@@ -68,7 +67,7 @@ func (s *Server) Run(ctx context.Context) error {
 	q := workqueue.NewNamedRateLimitingQueue(workqueue.DefaultControllerRateLimiter(), "podStatusUpdate")
 	s.runProviderSyncWorkers(ctx, q)
 
-	if pn, ok := s.provider.(providers.PodNotifier); ok {
+	if pn, ok := s.provider.(PodNotifier); ok {
 		pn.NotifyPods(ctx, func(pod *corev1.Pod) {
 			s.enqueuePodStatusUpdate(ctx, q, pod)
 		})