diff --git a/metrics-server/pkg/sources/fake/fakes.go b/metrics-server/pkg/sources/fake/fakes.go
new file mode 100644
index 0000000..4bbc9f9
--- /dev/null
+++ b/metrics-server/pkg/sources/fake/fakes.go
@@ -0,0 +1,46 @@
+// Copyright 2018 The Kubernetes Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fake
+
+import (
+	"context"
+
+	"github.com/kubernetes-incubator/metrics-server/pkg/sources"
+)
+
+// StaticSourceProvider is a fake sources.MetricSourceProvider that returns
+// metrics from a static list.
+type StaticSourceProvider []sources.MetricSource
+
+func (p StaticSourceProvider) GetMetricSources() ([]sources.MetricSource, error) { return p, nil }
+
+// FunctionSource is a sources.MetricSource that calls a function to
+// return the given data points
+type FunctionSource struct {
+	SourceName    string
+	GenerateBatch CollectFunc
+}
+
+func (f *FunctionSource) Name() string {
+	return f.SourceName
+}
+
+func (f *FunctionSource) Collect(ctx context.Context) (*sources.MetricsBatch, error) {
+	return f.GenerateBatch(ctx)
+}
+
+// CollectFunc is the function signature of FunctionSource#GenerateBatch,
+// and knows how to generate a MetricsBatch.
+type CollectFunc func(context.Context) (*sources.MetricsBatch, error)
diff --git a/metrics-server/pkg/sources/interfaces.go b/metrics-server/pkg/sources/interfaces.go
new file mode 100644
index 0000000..74a4d14
--- /dev/null
+++ b/metrics-server/pkg/sources/interfaces.go
@@ -0,0 +1,76 @@
+// Copyright 2018 The Kubernetes Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sources
+
+import (
+	"context"
+	"time"
+
+	"k8s.io/apimachinery/pkg/api/resource"
+)
+
+// MetricsBatch is a single batch of pod, container, and node metrics from some source.
+type MetricsBatch struct {
+	Nodes []NodeMetricsPoint
+	Pods  []PodMetricsPoint
+}
+
+// NodeMetricsPoint contains the metrics for some node at some point in time.
+type NodeMetricsPoint struct {
+	Name string
+	MetricsPoint
+}
+
+// PodMetricsPoint contains the metrics for some pod's containers.
+type PodMetricsPoint struct {
+	Name      string
+	Namespace string
+
+	Containers []ContainerMetricsPoint
+}
+
+// ContainerMetricsPoint contains the metrics for some container at some point in time.
+type ContainerMetricsPoint struct {
+	Name string
+	MetricsPoint
+}
+
+// MetricsPoint represents the a set of specific metrics at some point in time.
+type MetricsPoint struct {
+	Timestamp time.Time
+	// CpuUsage is the CPU usage rate, in cores
+	CpuUsage resource.Quantity
+	// MemoryUsage is the working set size, in bytes.
+	MemoryUsage resource.Quantity
+}
+
+// MetricSource knows how to collect pod, container, and node metrics from some location.
+// It is expected that the batch returned contains unique values (i.e. it does not return
+// the same node, pod, or container as any other source).
+type MetricSource interface {
+	// Collect fetches a batch of metrics.  It may return both a partial result and an error,
+	// and non-nil results thus must be well-formed and meaningful even when accompanied by 
+	// and error.
+	Collect(context.Context) (*MetricsBatch, error)
+	// Name names the metrics source for identification purposes
+	Name() string
+}
+
+// MetricSourceProvider provides metric sources to collect from.
+type MetricSourceProvider interface {
+	// GetMetricSources fetches all sources known to this metrics provider.
+	// It may return both partial results and an error.
+	GetMetricSources() ([]MetricSource, error)
+}
diff --git a/metrics-server/pkg/sources/manager.go b/metrics-server/pkg/sources/manager.go
new file mode 100644
index 0000000..ff5b4d0
--- /dev/null
+++ b/metrics-server/pkg/sources/manager.go
@@ -0,0 +1,165 @@
+// Copyright 2018 The Kubernetes Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sources
+
+import (
+	"context"
+	"fmt"
+	"math/rand"
+	"time"
+
+	"github.com/golang/glog"
+	"github.com/prometheus/client_golang/prometheus"
+	utilerrors "k8s.io/apimachinery/pkg/util/errors"
+
+	utilmetrics "github.com/kubernetes-incubator/metrics-server/pkg/metrics"
+)
+
+const (
+	maxDelayMs       = 4 * 1000
+	delayPerSourceMs = 8
+)
+
+var (
+	lastScrapeTimestamp = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Namespace: "metrics_server",
+			Subsystem: "scraper",
+			Name:      "last_time_seconds",
+			Help:      "Last time metrics-server performed a scrape since unix epoch in seconds.",
+		},
+		[]string{"source"},
+	)
+
+	// initialized below to an actual value by a call to RegisterScraperDuration
+	// (acts as a no-op by default), but we can't just register it in the constructor,
+	// since it could be called multiple times during setup.
+	scraperDuration *prometheus.HistogramVec = prometheus.NewHistogramVec(prometheus.HistogramOpts{}, []string{"source"})
+)
+
+func init() {
+	prometheus.MustRegister(lastScrapeTimestamp)
+}
+
+// RegisterScraperDuration creates and registers a histogram metric for
+// scrape duration, suitable for use in the source manager.
+func RegisterDurationMetrics(scrapeTimeout time.Duration) {
+	scraperDuration = prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Namespace: "metrics_server",
+			Subsystem: "scraper",
+			Name:      "duration_seconds",
+			Help:      "Time spent scraping sources in seconds.",
+			Buckets:   utilmetrics.BucketsForScrapeDuration(scrapeTimeout),
+		},
+		[]string{"source"},
+	)
+	prometheus.MustRegister(scraperDuration)
+}
+
+func NewSourceManager(srcProv MetricSourceProvider, scrapeTimeout time.Duration) MetricSource {
+	return &sourceManager{
+		srcProv:       srcProv,
+		scrapeTimeout: scrapeTimeout,
+	}
+}
+
+type sourceManager struct {
+	srcProv       MetricSourceProvider
+	scrapeTimeout time.Duration
+}
+
+func (m *sourceManager) Name() string {
+	return "source_manager"
+}
+
+func (m *sourceManager) Collect(baseCtx context.Context) (*MetricsBatch, error) {
+	sources, err := m.srcProv.GetMetricSources()
+	var errs []error
+	if err != nil {
+		// save the error, and continue on in case of partial results
+		errs = append(errs, err)
+	}
+	glog.V(1).Infof("Scraping metrics from %v sources", len(sources))
+
+	responseChannel := make(chan *MetricsBatch, len(sources))
+	errChannel := make(chan error, len(sources))
+	defer close(responseChannel)
+	defer close(errChannel)
+
+	startTime := time.Now()
+
+	// TODO(directxman12): re-evaluate this code -- do we really need to stagger fetches like this?
+	delayMs := delayPerSourceMs * len(sources)
+	if delayMs > maxDelayMs {
+		delayMs = maxDelayMs
+	}
+
+	for _, source := range sources {
+		go func(source MetricSource) {
+			// Prevents network congestion.
+			sleepDuration := time.Duration(rand.Intn(delayMs)) * time.Millisecond
+			time.Sleep(sleepDuration)
+			// make the timeout a bit shorter to account for staggering, so we still preserve
+			// the overall timeout
+			ctx, cancelTimeout := context.WithTimeout(baseCtx, m.scrapeTimeout-sleepDuration)
+			defer cancelTimeout()
+
+			glog.V(2).Infof("Querying source: %s", source)
+			metrics, err := scrapeWithMetrics(ctx, source)
+			if err != nil {
+				errChannel <- fmt.Errorf("unable to fully scrape metrics from source %s: %v", source.Name(), err)
+				responseChannel <- metrics
+				return
+			}
+			responseChannel <- metrics
+			errChannel <- nil
+		}(source)
+	}
+
+	res := &MetricsBatch{}
+
+	for range sources {
+		err := <-errChannel
+		srcBatch := <-responseChannel
+		if err != nil {
+			errs = append(errs, err)
+			// NB: partial node results are still worth saving, so
+			// don't skip storing results if we got an error
+		}
+		if srcBatch == nil {
+			continue
+		}
+
+		res.Nodes = append(res.Nodes, srcBatch.Nodes...)
+		res.Pods = append(res.Pods, srcBatch.Pods...)
+	}
+
+	glog.V(1).Infof("ScrapeMetrics: time: %s, nodes: %v, pods: %v", time.Since(startTime), len(res.Nodes), len(res.Pods))
+	return res, utilerrors.NewAggregate(errs)
+}
+
+func scrapeWithMetrics(ctx context.Context, s MetricSource) (*MetricsBatch, error) {
+	sourceName := s.Name()
+	startTime := time.Now()
+	defer lastScrapeTimestamp.
+		WithLabelValues(sourceName).
+		Set(float64(time.Now().Unix()))
+	defer scraperDuration.
+		WithLabelValues(sourceName).
+		Observe(float64(time.Since(startTime)) / float64(time.Second))
+
+	return s.Collect(ctx)
+}
diff --git a/metrics-server/pkg/sources/manager_test.go b/metrics-server/pkg/sources/manager_test.go
new file mode 100644
index 0000000..78bf436
--- /dev/null
+++ b/metrics-server/pkg/sources/manager_test.go
@@ -0,0 +1,218 @@
+// Copyright 2018 The Kubernetes Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sources_test
+
+import (
+	"context"
+	"fmt"
+	"testing"
+	"time"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"k8s.io/apimachinery/pkg/api/resource"
+
+	. "github.com/kubernetes-incubator/metrics-server/pkg/sources"
+	fakesrc "github.com/kubernetes-incubator/metrics-server/pkg/sources/fake"
+)
+
+func TestSourceManager(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Source Manager Suite")
+}
+
+// sleepySource returns a MetricSource that takes some amount of time (respecting
+// context timeouts) to collect a MetricsBatch with a single node's data point.
+func sleepySource(delay time.Duration, nodeName string, point MetricsPoint) MetricSource {
+	return &fakesrc.FunctionSource{
+		SourceName: "sleepy_source:" + nodeName,
+		GenerateBatch: func(ctx context.Context) (*MetricsBatch, error) {
+			select {
+			case <-time.After(delay):
+			case <-ctx.Done():
+				return nil, fmt.Errorf("timed out")
+			}
+			return &MetricsBatch{
+				Nodes: []NodeMetricsPoint{
+					{
+						Name:         nodeName,
+						MetricsPoint: point,
+					},
+				},
+			}, nil
+		},
+	}
+}
+
+func fullSource(ts time.Time, nodeInd, podStartInd, numPods int) MetricSource {
+	return &fakesrc.FunctionSource{
+		SourceName: fmt.Sprintf("static_source:node%d", nodeInd),
+		GenerateBatch: func(_ context.Context) (*MetricsBatch, error) {
+			podPoints := make([]PodMetricsPoint, numPods)
+			for i := range podPoints {
+				podInd := int64(podStartInd + i)
+				podPoints[i].Name = fmt.Sprintf("pod%d", podInd)
+				podPoints[i].Namespace = fmt.Sprintf("ns%d", nodeInd)
+				podPoints[i].Containers = []ContainerMetricsPoint{
+					{
+						Name: "container1",
+						MetricsPoint: MetricsPoint{
+							Timestamp:   ts,
+							CpuUsage:    *resource.NewQuantity(300+10*podInd, resource.DecimalSI),
+							MemoryUsage: *resource.NewQuantity(400+10*podInd, resource.DecimalSI),
+						},
+					},
+					{
+						Name: "container2",
+						MetricsPoint: MetricsPoint{
+							Timestamp:   ts,
+							CpuUsage:    *resource.NewQuantity(500+10*podInd, resource.DecimalSI),
+							MemoryUsage: *resource.NewQuantity(600+10*podInd, resource.DecimalSI),
+						},
+					},
+				}
+			}
+			return &MetricsBatch{
+				Nodes: []NodeMetricsPoint{
+					{
+						Name: fmt.Sprintf("node%d", nodeInd),
+						MetricsPoint: MetricsPoint{
+							Timestamp:   ts,
+							CpuUsage:    *resource.NewQuantity(100+10*int64(nodeInd), resource.DecimalSI),
+							MemoryUsage: *resource.NewQuantity(200+10*int64(nodeInd), resource.DecimalSI),
+						},
+					},
+				},
+				Pods: podPoints,
+			}, nil
+		},
+	}
+}
+
+var _ = Describe("Source Manager", func() {
+	var (
+		scrapeTime    = time.Now()
+		nodeDataPoint = MetricsPoint{
+			Timestamp:   scrapeTime,
+			CpuUsage:    *resource.NewQuantity(100, resource.DecimalSI),
+			MemoryUsage: *resource.NewQuantity(200, resource.DecimalSI),
+		}
+	)
+
+	Context("when all sources return in time", func() {
+		It("should return the results of all sources, both pods and nodes", func() {
+			By("setting up sources that take 1 second to complete")
+			metricsSourceProvider := fakesrc.StaticSourceProvider{
+				sleepySource(1*time.Second, "node1", nodeDataPoint),
+				sleepySource(1*time.Second, "node2", nodeDataPoint),
+			}
+
+			By("running the source manager with a scrape and context timeout of 3*seconds")
+			start := time.Now()
+			manager := NewSourceManager(metricsSourceProvider, 3*time.Second)
+			timeoutCtx, doneWithWork := context.WithTimeout(context.Background(), 3*time.Second)
+			dataBatch, errs := manager.Collect(timeoutCtx)
+			doneWithWork()
+			Expect(errs).NotTo(HaveOccurred())
+
+			By("ensuring that the full time took at most 3 seconds")
+			Expect(time.Now().Sub(start)).To(BeNumerically("<=", 3*time.Second))
+
+			By("ensuring that all the nodes are listed")
+			Expect(dataBatch.Nodes).To(ConsistOf(
+				NodeMetricsPoint{Name: "node1", MetricsPoint: nodeDataPoint},
+				NodeMetricsPoint{Name: "node2", MetricsPoint: nodeDataPoint},
+			))
+		})
+
+		It("should return the results of all sources' nodes and pods", func() {
+			By("setting up multiple sources")
+			metricsSourceProvider := fakesrc.StaticSourceProvider{
+				fullSource(scrapeTime, 1, 0, 4),
+				fullSource(scrapeTime, 2, 4, 2),
+				fullSource(scrapeTime, 3, 6, 1),
+			}
+
+			By("running the source manager")
+			manager := NewSourceManager(metricsSourceProvider, 1*time.Second)
+			dataBatch, errs := manager.Collect(context.Background())
+			Expect(errs).NotTo(HaveOccurred())
+
+			By("figuring out the expected node and pod points")
+			var expectedNodePoints []interface{}
+			var expectedPodPoints []interface{}
+			for _, src := range metricsSourceProvider {
+				res, err := src.Collect(context.Background())
+				Expect(err).NotTo(HaveOccurred())
+				for _, pt := range res.Nodes {
+					expectedNodePoints = append(expectedNodePoints, pt)
+				}
+				for _, pt := range res.Pods {
+					expectedPodPoints = append(expectedPodPoints, pt)
+				}
+			}
+
+			By("ensuring that all nodes are present")
+			Expect(dataBatch.Nodes).To(ConsistOf(expectedNodePoints...))
+
+			By("ensuring that all pods are present")
+			Expect(dataBatch.Pods).To(ConsistOf(expectedPodPoints...))
+		})
+	})
+
+	Context("when some sources take too long", func() {
+		It("should pass the scrape timeout to the source context, so that sources can time out", func() {
+			By("setting up one source to take 4 seconds, and another to take 2")
+			metricsSourceProvider := fakesrc.StaticSourceProvider{
+				sleepySource(4*time.Second, "node1", nodeDataPoint),
+				sleepySource(2*time.Second, "node2", nodeDataPoint),
+			}
+
+			By("running the source manager with a scrape timeout of 3 seconds")
+			start := time.Now()
+			manager := NewSourceManager(metricsSourceProvider, 3*time.Second)
+			dataBatch, errs := manager.Collect(context.Background())
+
+			By("ensuring that scraping took around 3 seconds")
+			Expect(time.Now().Sub(start)).To(BeNumerically("~", 3*time.Second, 1*time.Millisecond))
+
+			By("ensuring that an error and partial results (data from source 2) were returned")
+			Expect(errs).To(HaveOccurred())
+			Expect(dataBatch.Nodes).To(ConsistOf(
+				NodeMetricsPoint{Name: "node2", MetricsPoint: nodeDataPoint},
+			))
+		})
+
+		It("should respect the parent context's general timeout, even with a longer scrape timeout", func() {
+			By("setting up some sources with 4 second delays")
+			metricsSourceProvider := fakesrc.StaticSourceProvider{
+				sleepySource(4*time.Second, "node1", nodeDataPoint),
+				sleepySource(4*time.Second, "node2", nodeDataPoint),
+			}
+
+			By("running the source manager with a scrape timeout of 5 seconds, but a context timeout of 1 second")
+			start := time.Now()
+			manager := NewSourceManager(metricsSourceProvider, 5*time.Second)
+			timeoutCtx, doneWithWork := context.WithTimeout(context.Background(), 1*time.Second)
+			dataBatch, errs := manager.Collect(timeoutCtx)
+			doneWithWork()
+
+			By("ensuring that it times out after 1 second with errors and no data")
+			Expect(time.Now().Sub(start)).To(BeNumerically("~", 1*time.Second, 1*time.Millisecond))
+			Expect(errs).To(HaveOccurred())
+			Expect(dataBatch.Nodes).To(BeEmpty())
+		})
+	})
+})
diff --git a/metrics-server/pkg/sources/summary/addrs.go b/metrics-server/pkg/sources/summary/addrs.go
new file mode 100644
index 0000000..49e7fc1
--- /dev/null
+++ b/metrics-server/pkg/sources/summary/addrs.go
@@ -0,0 +1,76 @@
+// Copyright 2018 The Kubernetes Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package summary
+
+import (
+	"fmt"
+
+	corev1 "k8s.io/api/core/v1"
+)
+
+var (
+	// DefaultAddressTypePriority is the default node address type
+	// priority list, as taken from the Kubernetes API server options.
+	// In general, we prefer overrides to others, internal to external,
+	// and DNS to IPs.
+	DefaultAddressTypePriority = []corev1.NodeAddressType{
+		// --override-hostname
+		corev1.NodeHostName,
+
+		// internal, preferring DNS if reported
+		corev1.NodeInternalDNS,
+		corev1.NodeInternalIP,
+
+		// external, preferring DNS if reported
+		corev1.NodeExternalDNS,
+		corev1.NodeExternalIP,
+	}
+)
+
+// NodeAddressResolver knows how to find the preferred connection
+// address for a given node.
+type NodeAddressResolver interface {
+	// NodeAddress finds the preferred address to use to connect to
+	// the given node.
+	NodeAddress(node *corev1.Node) (address string, err error)
+}
+
+// prioNodeAddrResolver finds node addresses according to a list of
+// priorities of types of addresses.
+type prioNodeAddrResolver struct {
+	addrTypePriority []corev1.NodeAddressType
+}
+
+func (r *prioNodeAddrResolver) NodeAddress(node *corev1.Node) (string, error) {
+	// adapted from k8s.io/kubernetes/pkg/util/node
+	for _, addrType := range r.addrTypePriority {
+		for _, addr := range node.Status.Addresses {
+			if addr.Type == addrType {
+				return addr.Address, nil
+			}
+		}
+	}
+
+	return "", fmt.Errorf("node %s had no addresses that matched types %v", node.Name, r.addrTypePriority)
+}
+
+// NewPriorityNodeAddressResolver creates a new NodeAddressResolver that resolves
+// addresses first based on a list of prioritized address types, then based on
+// address order (first to last) within a particular address type.
+func NewPriorityNodeAddressResolver(typePriority []corev1.NodeAddressType) NodeAddressResolver {
+	return &prioNodeAddrResolver{
+		addrTypePriority: typePriority,
+	}
+}
diff --git a/metrics-server/pkg/sources/summary/client.go b/metrics-server/pkg/sources/summary/client.go
new file mode 100644
index 0000000..21e3aed
--- /dev/null
+++ b/metrics-server/pkg/sources/summary/client.go
@@ -0,0 +1,119 @@
+// Copyright 2018 The Kubernetes Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package summary
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"strconv"
+
+	"github.com/golang/glog"
+	stats "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
+)
+
+// KubeletInterface knows how to fetch metrics from the Kubelet
+type KubeletInterface interface {
+	// GetSummary fetches summary metrics from the given Kubelet
+	GetSummary(ctx context.Context, host string) (*stats.Summary, error)
+}
+
+type kubeletClient struct {
+	port            int
+	deprecatedNoTLS bool
+	client          *http.Client
+}
+
+type ErrNotFound struct {
+	endpoint string
+}
+
+func (err *ErrNotFound) Error() string {
+	return fmt.Sprintf("%q not found", err.endpoint)
+}
+
+func IsNotFoundError(err error) bool {
+	_, isNotFound := err.(*ErrNotFound)
+	return isNotFound
+}
+
+func (kc *kubeletClient) makeRequestAndGetValue(client *http.Client, req *http.Request, value interface{}) error {
+	// TODO(directxman12): support validating certs by hostname
+	response, err := client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	body, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		return fmt.Errorf("failed to read response body - %v", err)
+	}
+	if response.StatusCode == http.StatusNotFound {
+		return &ErrNotFound{req.URL.String()}
+	} else if response.StatusCode != http.StatusOK {
+		return fmt.Errorf("request failed - %q, response: %q", response.Status, string(body))
+	}
+
+	kubeletAddr := "[unknown]"
+	if req.URL != nil {
+		kubeletAddr = req.URL.Host
+	}
+	glog.V(10).Infof("Raw response from Kubelet at %s: %s", kubeletAddr, string(body))
+
+	err = json.Unmarshal(body, value)
+	if err != nil {
+		return fmt.Errorf("failed to parse output. Response: %q. Error: %v", string(body), err)
+	}
+	return nil
+}
+
+func (kc *kubeletClient) GetSummary(ctx context.Context, host string) (*stats.Summary, error) {
+	scheme := "https"
+	if kc.deprecatedNoTLS {
+		scheme = "http"
+	}
+	url := url.URL{
+		Scheme: scheme,
+		Host:   net.JoinHostPort(host, strconv.Itoa(kc.port)),
+		Path:   "/stats/summary/",
+	}
+
+	req, err := http.NewRequest("GET", url.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+	summary := &stats.Summary{}
+	client := kc.client
+	if client == nil {
+		client = http.DefaultClient
+	}
+	err = kc.makeRequestAndGetValue(client, req.WithContext(ctx), summary)
+	return summary, err
+}
+
+func NewKubeletClient(transport http.RoundTripper, port int, deprecatedNoTLS bool) (KubeletInterface, error) {
+	c := &http.Client{
+		Transport: transport,
+	}
+	return &kubeletClient{
+		port:            port,
+		client:          c,
+		deprecatedNoTLS: deprecatedNoTLS,
+	}, nil
+}
diff --git a/metrics-server/pkg/sources/summary/configs.go b/metrics-server/pkg/sources/summary/configs.go
new file mode 100644
index 0000000..e5da658
--- /dev/null
+++ b/metrics-server/pkg/sources/summary/configs.go
@@ -0,0 +1,58 @@
+// Copyright 2018 The Kubernetes Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package summary
+
+import (
+	"fmt"
+
+	"k8s.io/client-go/rest"
+)
+
+// GetKubeletConfig fetches connection config for connecting to the Kubelet.
+func GetKubeletConfig(baseKubeConfig *rest.Config, port int, insecureTLS bool, completelyInsecure bool) *KubeletClientConfig {
+	cfg := rest.CopyConfig(baseKubeConfig)
+	if completelyInsecure {
+		cfg = rest.AnonymousClientConfig(cfg)        // don't use auth to avoid leaking auth details to insecure endpoints
+		cfg.TLSClientConfig = rest.TLSClientConfig{} // empty TLS config --> no TLS
+	} else if insecureTLS {
+		cfg.TLSClientConfig.Insecure = true
+		cfg.TLSClientConfig.CAData = nil
+		cfg.TLSClientConfig.CAFile = ""
+	}
+	kubeletConfig := &KubeletClientConfig{
+		Port:                         port,
+		RESTConfig:                   cfg,
+		DeprecatedCompletelyInsecure: completelyInsecure,
+	}
+
+	return kubeletConfig
+}
+
+// KubeletClientConfig represents configuration for connecting to Kubelets.
+type KubeletClientConfig struct {
+	Port                         int
+	RESTConfig                   *rest.Config
+	DeprecatedCompletelyInsecure bool
+}
+
+// KubeletClientFor constructs a new KubeletInterface for the given configuration.
+func KubeletClientFor(config *KubeletClientConfig) (KubeletInterface, error) {
+	transport, err := rest.TransportFor(config.RESTConfig)
+	if err != nil {
+		return nil, fmt.Errorf("unable to construct transport: %v", err)
+	}
+
+	return NewKubeletClient(transport, config.Port, config.DeprecatedCompletelyInsecure)
+}
diff --git a/metrics-server/pkg/sources/summary/summary.go b/metrics-server/pkg/sources/summary/summary.go
new file mode 100644
index 0000000..667d74b
--- /dev/null
+++ b/metrics-server/pkg/sources/summary/summary.go
@@ -0,0 +1,295 @@
+// Copyright 2018 The Kubernetes Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package summary
+
+import (
+	"context"
+	"fmt"
+	"math"
+	"time"
+
+	"github.com/golang/glog"
+	"github.com/kubernetes-incubator/metrics-server/pkg/sources"
+	"github.com/prometheus/client_golang/prometheus"
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
+	"k8s.io/apimachinery/pkg/labels"
+	utilerrors "k8s.io/apimachinery/pkg/util/errors"
+	v1listers "k8s.io/client-go/listers/core/v1"
+	stats "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
+)
+
+var (
+	summaryRequestLatency = prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Namespace: "metrics_server",
+			Subsystem: "kubelet_summary",
+			Name:      "request_duration_seconds",
+			Help:      "The Kubelet summary request latencies in seconds.",
+			// TODO(directxman12): it would be nice to calculate these buckets off of scrape duration,
+			// like we do elsewhere, but we're not passed the scrape duration at this level.
+			Buckets: prometheus.DefBuckets,
+		},
+		[]string{"node"},
+	)
+	scrapeTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "metrics_server",
+			Subsystem: "kubelet_summary",
+			Name:      "scrapes_total",
+			Help:      "Total number of attempted Summary API scrapes done by Metrics Server",
+		},
+		[]string{"success"},
+	)
+)
+
+func init() {
+	prometheus.MustRegister(summaryRequestLatency)
+	prometheus.MustRegister(scrapeTotal)
+}
+
+// NodeInfo contains the information needed to identify and connect to a particular node
+// (node name and preferred address).
+type NodeInfo struct {
+	Name           string
+	ConnectAddress string
+}
+
+// Kubelet-provided metrics for pod and system container.
+type summaryMetricsSource struct {
+	node          NodeInfo
+	kubeletClient KubeletInterface
+}
+
+func NewSummaryMetricsSource(node NodeInfo, client KubeletInterface) sources.MetricSource {
+	return &summaryMetricsSource{
+		node:          node,
+		kubeletClient: client,
+	}
+}
+
+func (src *summaryMetricsSource) Name() string {
+	return src.String()
+}
+
+func (src *summaryMetricsSource) String() string {
+	return fmt.Sprintf("kubelet_summary:%s", src.node.Name)
+}
+
+func (src *summaryMetricsSource) Collect(ctx context.Context) (*sources.MetricsBatch, error) {
+	summary, err := func() (*stats.Summary, error) {
+		startTime := time.Now()
+		defer summaryRequestLatency.WithLabelValues(src.node.Name).Observe(float64(time.Since(startTime)) / float64(time.Second))
+		return src.kubeletClient.GetSummary(ctx, src.node.ConnectAddress)
+	}()
+
+	if err != nil {
+		scrapeTotal.WithLabelValues("false").Inc()
+		return nil, fmt.Errorf("unable to fetch metrics from Kubelet %s (%s): %v", src.node.Name, src.node.ConnectAddress, err)
+	}
+
+	scrapeTotal.WithLabelValues("true").Inc()
+
+	res := &sources.MetricsBatch{
+		Nodes: make([]sources.NodeMetricsPoint, 1),
+		Pods:  make([]sources.PodMetricsPoint, len(summary.Pods)),
+	}
+
+	var errs []error
+	errs = append(errs, src.decodeNodeStats(&summary.Node, &res.Nodes[0])...)
+	if len(errs) != 0 {
+		// if we had errors providing node metrics, discard the data point
+		// so that we don't incorrectly report metric values as zero.
+		res.Nodes = res.Nodes[:1]
+	}
+
+	num := 0
+	for _, pod := range summary.Pods {
+		podErrs := src.decodePodStats(&pod, &res.Pods[num])
+		errs = append(errs, podErrs...)
+		if len(podErrs) != 0 {
+			// NB: we explicitly want to discard pods with partial results, since
+			// the horizontal pod autoscaler takes special action when a pod is missing
+			// metrics (and zero CPU or memory does not count as "missing metrics")
+
+			// we don't care if we reuse slots in the result array,
+			// because they get completely overwritten in decodePodStats
+			continue
+		}
+		num++
+	}
+	res.Pods = res.Pods[:num]
+
+	return res, utilerrors.NewAggregate(errs)
+}
+
+func (src *summaryMetricsSource) decodeNodeStats(nodeStats *stats.NodeStats, target *sources.NodeMetricsPoint) []error {
+	timestamp, err := getScrapeTime(nodeStats.CPU, nodeStats.Memory)
+	if err != nil {
+		// if we can't get a timestamp, assume bad data in general
+		return []error{fmt.Errorf("unable to get valid timestamp for metric point for node %q, discarding data: %v", src.node.ConnectAddress, err)}
+	}
+	*target = sources.NodeMetricsPoint{
+		Name: src.node.Name,
+		MetricsPoint: sources.MetricsPoint{
+			Timestamp: timestamp,
+		},
+	}
+	var errs []error
+	if err := decodeCPU(&target.CpuUsage, nodeStats.CPU); err != nil {
+		errs = append(errs, fmt.Errorf("unable to get CPU for node %q, discarding data: %v", src.node.ConnectAddress, err))
+	}
+	if err := decodeMemory(&target.MemoryUsage, nodeStats.Memory); err != nil {
+		errs = append(errs, fmt.Errorf("unable to get memory for node %q, discarding data: %v", src.node.ConnectAddress, err))
+	}
+	return errs
+}
+
+func (src *summaryMetricsSource) decodePodStats(podStats *stats.PodStats, target *sources.PodMetricsPoint) []error {
+	// completely overwrite data in the target
+	*target = sources.PodMetricsPoint{
+		Name:       podStats.PodRef.Name,
+		Namespace:  podStats.PodRef.Namespace,
+		Containers: make([]sources.ContainerMetricsPoint, len(podStats.Containers)),
+	}
+
+	var errs []error
+	for i, container := range podStats.Containers {
+		timestamp, err := getScrapeTime(container.CPU, container.Memory)
+		if err != nil {
+			// if we can't get a timestamp, assume bad data in general
+			errs = append(errs, fmt.Errorf("unable to get a valid timestamp for metric point for container %q in pod %s/%s on node %q, discarding data: %v", container.Name, target.Namespace, target.Name, src.node.ConnectAddress, err))
+			continue
+		}
+		point := sources.ContainerMetricsPoint{
+			Name: container.Name,
+			MetricsPoint: sources.MetricsPoint{
+				Timestamp: timestamp,
+			},
+		}
+		if err := decodeCPU(&point.CpuUsage, container.CPU); err != nil {
+			errs = append(errs, fmt.Errorf("unable to get CPU for container %q in pod %s/%s on node %q, discarding data: %v", container.Name, target.Namespace, target.Name, src.node.ConnectAddress, err))
+		}
+		if err := decodeMemory(&point.MemoryUsage, container.Memory); err != nil {
+			errs = append(errs, fmt.Errorf("unable to get memory for container %q in pod %s/%s on node %q: %v, discarding data", container.Name, target.Namespace, target.Name, src.node.ConnectAddress, err))
+		}
+
+		target.Containers[i] = point
+	}
+
+	return errs
+}
+
+func decodeCPU(target *resource.Quantity, cpuStats *stats.CPUStats) error {
+	if cpuStats == nil || cpuStats.UsageNanoCores == nil {
+		return fmt.Errorf("missing cpu usage metric")
+	}
+
+	*target = *uint64Quantity(*cpuStats.UsageNanoCores, -9)
+	return nil
+}
+
+func decodeMemory(target *resource.Quantity, memStats *stats.MemoryStats) error {
+	if memStats == nil || memStats.WorkingSetBytes == nil {
+		return fmt.Errorf("missing memory usage metric")
+	}
+
+	*target = *uint64Quantity(*memStats.WorkingSetBytes, 0)
+	target.Format = resource.BinarySI
+
+	return nil
+}
+
+func getScrapeTime(cpu *stats.CPUStats, memory *stats.MemoryStats) (time.Time, error) {
+	// Ensure we get the earlier timestamp so that we can tell if a given data
+	// point was tainted by pod initialization.
+
+	var earliest *time.Time
+	if cpu != nil && !cpu.Time.IsZero() && (earliest == nil || earliest.After(cpu.Time.Time)) {
+		earliest = &cpu.Time.Time
+	}
+
+	if memory != nil && !memory.Time.IsZero() && (earliest == nil || earliest.After(memory.Time.Time)) {
+		earliest = &memory.Time.Time
+	}
+
+	if earliest == nil {
+		return time.Time{}, fmt.Errorf("no non-zero timestamp on either CPU or memory")
+	}
+
+	return *earliest, nil
+}
+
+// uint64Quantity converts a uint64 into a Quantity, which only has constructors
+// that work with int64 (except for parse, which requires costly round-trips to string).
+// We lose precision until we fit in an int64 if greater than the max int64 value.
+func uint64Quantity(val uint64, scale resource.Scale) *resource.Quantity {
+	// easy path -- we can safely fit val into an int64
+	if val <= math.MaxInt64 {
+		return resource.NewScaledQuantity(int64(val), scale)
+	}
+
+	glog.V(1).Infof("unexpectedly large resource value %v, loosing precision to fit in scaled resource.Quantity", val)
+
+	// otherwise, lose an decimal order-of-magnitude precision,
+	// so we can fit into a scaled quantity
+	return resource.NewScaledQuantity(int64(val/10), resource.Scale(1)+scale)
+}
+
+type summaryProvider struct {
+	nodeLister    v1listers.NodeLister
+	kubeletClient KubeletInterface
+	addrResolver  NodeAddressResolver
+}
+
+func (p *summaryProvider) GetMetricSources() ([]sources.MetricSource, error) {
+	sources := []sources.MetricSource{}
+	nodes, err := p.nodeLister.List(labels.Everything())
+	if err != nil {
+		return nil, fmt.Errorf("unable to list nodes: %v", err)
+	}
+
+	var errs []error
+	for _, node := range nodes {
+		info, err := p.getNodeInfo(node)
+		if err != nil {
+			errs = append(errs, fmt.Errorf("unable to extract connection information for node %q: %v", node.Name, err))
+			continue
+		}
+		sources = append(sources, NewSummaryMetricsSource(info, p.kubeletClient))
+	}
+	return sources, utilerrors.NewAggregate(errs)
+}
+
+func (p *summaryProvider) getNodeInfo(node *corev1.Node) (NodeInfo, error) {
+	addr, err := p.addrResolver.NodeAddress(node)
+	if err != nil {
+		return NodeInfo{}, err
+	}
+	info := NodeInfo{
+		Name:           node.Name,
+		ConnectAddress: addr,
+	}
+
+	return info, nil
+}
+
+func NewSummaryProvider(nodeLister v1listers.NodeLister, kubeletClient KubeletInterface, addrResolver NodeAddressResolver) sources.MetricSourceProvider {
+	return &summaryProvider{
+		nodeLister:    nodeLister,
+		kubeletClient: kubeletClient,
+		addrResolver:  addrResolver,
+	}
+}
diff --git a/metrics-server/pkg/sources/summary/summary_test.go b/metrics-server/pkg/sources/summary/summary_test.go
new file mode 100644
index 0000000..69672e0
--- /dev/null
+++ b/metrics-server/pkg/sources/summary/summary_test.go
@@ -0,0 +1,492 @@
+// Copyright 2018 The Kubernetes Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package summary_test
+
+import (
+	"context"
+	"fmt"
+	"math"
+	"testing"
+	"time"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/labels"
+	corelisters "k8s.io/client-go/listers/core/v1"
+	stats "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
+
+	"github.com/kubernetes-incubator/metrics-server/pkg/sources"
+	. "github.com/kubernetes-incubator/metrics-server/pkg/sources/summary"
+)
+
+func TestSummarySource(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Summary Source Test Suite")
+}
+
+type fakeKubeletClient struct {
+	delay   time.Duration
+	metrics *stats.Summary
+
+	lastHost string
+}
+
+func (c *fakeKubeletClient) GetSummary(ctx context.Context, host string) (*stats.Summary, error) {
+	select {
+	case <-ctx.Done():
+		return nil, fmt.Errorf("timed out")
+	case <-time.After(c.delay):
+	}
+
+	c.lastHost = host
+
+	return c.metrics, nil
+}
+
+func cpuStats(usageNanocores uint64, ts time.Time) *stats.CPUStats {
+	return &stats.CPUStats{
+		Time:           metav1.Time{ts},
+		UsageNanoCores: &usageNanocores,
+	}
+}
+
+func memStats(workingSetBytes uint64, ts time.Time) *stats.MemoryStats {
+	return &stats.MemoryStats{
+		Time:            metav1.Time{ts},
+		WorkingSetBytes: &workingSetBytes,
+	}
+}
+
+func podStats(namespace, name string, containers ...stats.ContainerStats) stats.PodStats {
+	return stats.PodStats{
+		PodRef: stats.PodReference{
+			Name:      name,
+			Namespace: namespace,
+		},
+		Containers: containers,
+	}
+}
+
+func containerStats(name string, cpu, mem uint64, baseTime time.Time) stats.ContainerStats {
+	return stats.ContainerStats{
+		Name:   name,
+		CPU:    cpuStats(cpu, baseTime.Add(2*time.Millisecond)),
+		Memory: memStats(mem, baseTime.Add(4*time.Millisecond)),
+	}
+}
+
+func verifyNode(nodeName string, summary *stats.Summary, batch *sources.MetricsBatch) {
+	var cpuUsage, memoryUsage resource.Quantity
+	var timestamp time.Time
+	if summary.Node.CPU != nil {
+		if summary.Node.CPU.UsageNanoCores != nil {
+			cpuUsage = *resource.NewScaledQuantity(int64(*summary.Node.CPU.UsageNanoCores), -9)
+		}
+		timestamp = summary.Node.CPU.Time.Time
+	}
+	if summary.Node.Memory != nil {
+		if summary.Node.Memory.WorkingSetBytes != nil {
+			memoryUsage = *resource.NewQuantity(int64(*summary.Node.Memory.WorkingSetBytes), resource.BinarySI)
+		}
+		if timestamp.IsZero() {
+			timestamp = summary.Node.Memory.Time.Time
+		}
+	}
+
+	Expect(batch.Nodes).To(ConsistOf(
+		sources.NodeMetricsPoint{
+			Name: nodeName,
+			MetricsPoint: sources.MetricsPoint{
+				Timestamp:   timestamp,
+				CpuUsage:    cpuUsage,
+				MemoryUsage: memoryUsage,
+			},
+		},
+	))
+}
+
+func verifyPods(summary *stats.Summary, batch *sources.MetricsBatch) {
+	var expectedPods []interface{}
+	for _, pod := range summary.Pods {
+		containers := make([]sources.ContainerMetricsPoint, len(pod.Containers))
+		missingData := false
+		for i, container := range pod.Containers {
+			var cpuUsage, memoryUsage resource.Quantity
+			var timestamp time.Time
+			if container.CPU == nil || container.CPU.UsageNanoCores == nil {
+				missingData = true
+				break
+			}
+			cpuUsage = *resource.NewScaledQuantity(int64(*container.CPU.UsageNanoCores), -9)
+			timestamp = container.CPU.Time.Time
+			if container.Memory == nil || container.Memory.WorkingSetBytes == nil {
+				missingData = true
+				break
+			}
+			memoryUsage = *resource.NewQuantity(int64(*container.Memory.WorkingSetBytes), resource.BinarySI)
+			if timestamp.IsZero() {
+				timestamp = container.Memory.Time.Time
+			}
+
+			containers[i] = sources.ContainerMetricsPoint{
+				Name: container.Name,
+				MetricsPoint: sources.MetricsPoint{
+					Timestamp:   timestamp,
+					CpuUsage:    cpuUsage,
+					MemoryUsage: memoryUsage,
+				},
+			}
+		}
+		if missingData {
+			continue
+		}
+		expectedPods = append(expectedPods, sources.PodMetricsPoint{
+			Name:       pod.PodRef.Name,
+			Namespace:  pod.PodRef.Namespace,
+			Containers: containers,
+		})
+	}
+	Expect(batch.Pods).To(ConsistOf(expectedPods...))
+}
+
+var _ = Describe("Summary Source", func() {
+	var (
+		src        sources.MetricSource
+		client     *fakeKubeletClient
+		scrapeTime time.Time = time.Now()
+		nodeInfo   NodeInfo  = NodeInfo{
+			ConnectAddress: "10.0.1.2",
+			Name:           "node1",
+		}
+	)
+	BeforeEach(func() {
+		client = &fakeKubeletClient{
+			metrics: &stats.Summary{
+				Node: stats.NodeStats{
+					CPU:    cpuStats(100, scrapeTime.Add(100*time.Millisecond)),
+					Memory: memStats(200, scrapeTime.Add(200*time.Millisecond)),
+				},
+				Pods: []stats.PodStats{
+					podStats("ns1", "pod1",
+						containerStats("container1", 300, 400, scrapeTime.Add(10*time.Millisecond)),
+						containerStats("container2", 500, 600, scrapeTime.Add(20*time.Millisecond))),
+					podStats("ns1", "pod2",
+						containerStats("container1", 700, 800, scrapeTime.Add(30*time.Millisecond))),
+					podStats("ns2", "pod1",
+						containerStats("container1", 900, 1000, scrapeTime.Add(40*time.Millisecond))),
+					podStats("ns3", "pod1",
+						containerStats("container1", 1100, 1200, scrapeTime.Add(50*time.Millisecond))),
+				},
+			},
+		}
+		src = NewSummaryMetricsSource(nodeInfo, client)
+	})
+
+	It("should pass the provided context to the kubelet client to time out requests", func() {
+		By("setting up a context with a 1 second timeout")
+		ctx, workDone := context.WithTimeout(context.Background(), 1*time.Second)
+
+		By("collecting the batch with a 4 second delay")
+		start := time.Now()
+		client.delay = 4 * time.Second
+		_, err := src.Collect(ctx)
+		workDone()
+
+		By("ensuring it timed out with an error after 1 second")
+		Expect(time.Now().Sub(start)).To(BeNumerically("~", 1*time.Second, 1*time.Millisecond))
+		Expect(err).To(HaveOccurred())
+	})
+
+	It("should fetch by connection address", func() {
+		By("collecting the batch")
+		_, err := src.Collect(context.Background())
+		Expect(err).NotTo(HaveOccurred())
+
+		By("verifying that it submitted the right host to the client")
+		Expect(client.lastHost).To(Equal(nodeInfo.ConnectAddress))
+	})
+
+	It("should return the working set and cpu usage for the node, and all pods on the node", func() {
+		By("collecting the batch")
+		batch, err := src.Collect(context.Background())
+		Expect(err).NotTo(HaveOccurred())
+
+		By("verifying that the batch contains the right node data")
+		verifyNode(nodeInfo.Name, client.metrics, batch)
+
+		By("verifying that the batch contains the right pod data")
+		verifyPods(client.metrics, batch)
+	})
+
+	It("should use the scrape time from the CPU, falling back to memory if missing", func() {
+		By("removing some times from the data")
+		client.metrics.Pods[0].Containers[0].CPU.Time = metav1.Time{}
+		client.metrics.Node.CPU.Time = metav1.Time{}
+
+		By("collecting the batch")
+		batch, err := src.Collect(context.Background())
+		Expect(err).NotTo(HaveOccurred())
+
+		By("verifying that the scrape time is as expected")
+		Expect(batch.Nodes[0].Timestamp).To(Equal(client.metrics.Node.Memory.Time.Time))
+		Expect(batch.Pods[0].Containers[0].Timestamp).To(Equal(client.metrics.Pods[0].Containers[0].Memory.Time.Time))
+		Expect(batch.Pods[1].Containers[0].Timestamp).To(Equal(client.metrics.Pods[1].Containers[0].CPU.Time.Time))
+	})
+
+	It("should continue on missing CPU or memory metrics", func() {
+		By("removing some data from the raw summary")
+		client.metrics.Node.Memory = nil
+		client.metrics.Pods[0].Containers[1].CPU = nil
+		client.metrics.Pods[1].Containers[0].CPU.UsageNanoCores = nil
+		client.metrics.Pods[2].Containers[0].Memory = nil
+		client.metrics.Pods[3].Containers[0].Memory.WorkingSetBytes = nil
+
+		By("collecting the batch")
+		batch, err := src.Collect(context.Background())
+		Expect(err).To(HaveOccurred())
+
+		By("verifying that the batch has all the data, save for what was missing")
+		verifyNode(nodeInfo.Name, client.metrics, batch)
+		verifyPods(client.metrics, batch)
+	})
+
+	It("should handle larger-than-int64 CPU or memory values gracefully", func() {
+		By("setting some data in the summary to be above math.MaxInt64")
+		plusTen := uint64(math.MaxInt64 + 10)
+		plusTwenty := uint64(math.MaxInt64 + 20)
+		minusTen := uint64(math.MaxUint64 - 10)
+		minusOneHundred := uint64(math.MaxUint64 - 100)
+
+		client.metrics.Node.Memory.WorkingSetBytes = &plusTen // RAM is cheap, right?
+		client.metrics.Node.CPU.UsageNanoCores = &plusTwenty  // a mainframe, probably
+		client.metrics.Pods[0].Containers[1].CPU.UsageNanoCores = &minusTen
+		client.metrics.Pods[1].Containers[0].Memory.WorkingSetBytes = &minusOneHundred
+
+		By("collecting the batch")
+		batch, err := src.Collect(context.Background())
+		Expect(err).NotTo(HaveOccurred())
+
+		By("verifying that the data is still present, at lower precision")
+		nodeMem := *resource.NewScaledQuantity(int64(plusTen/10), 1)
+		nodeMem.Format = resource.BinarySI
+		podMem := *resource.NewScaledQuantity(int64(minusOneHundred/10), 1)
+		podMem.Format = resource.BinarySI
+		Expect(batch.Nodes[0].MemoryUsage).To(Equal(nodeMem))
+		Expect(batch.Nodes[0].CpuUsage).To(Equal(*resource.NewScaledQuantity(int64(plusTwenty/10), -8)))
+		Expect(batch.Pods[0].Containers[1].CpuUsage).To(Equal(*resource.NewScaledQuantity(int64(minusTen/10), -8)))
+		Expect(batch.Pods[1].Containers[0].MemoryUsage).To(Equal(podMem))
+	})
+})
+
+type fakeNodeLister struct {
+	nodes   []*corev1.Node
+	listErr error
+}
+
+func (l *fakeNodeLister) List(_ labels.Selector) (ret []*corev1.Node, err error) {
+	if l.listErr != nil {
+		return nil, l.listErr
+	}
+	// NB: this is ignores selector for the moment
+	return l.nodes, nil
+}
+
+func (l *fakeNodeLister) ListWithPredicate(_ corelisters.NodeConditionPredicate) ([]*corev1.Node, error) {
+	// NB: this is ignores predicate for the moment
+	return l.List(labels.Everything())
+}
+
+func (l *fakeNodeLister) Get(name string) (*corev1.Node, error) {
+	for _, node := range l.nodes {
+		if node.Name == name {
+			return node, nil
+		}
+	}
+	return nil, fmt.Errorf("no such node %q", name)
+}
+
+func nodeNames(nodes []*corev1.Node, addrs []string) []string {
+	var res []string
+	for i, node := range nodes {
+		res = append(res, NewSummaryMetricsSource(NodeInfo{ConnectAddress: addrs[i], Name: node.Name}, nil).Name())
+	}
+	return res
+}
+
+func makeNode(name, hostName, addr string, ready bool) *corev1.Node {
+	res := &corev1.Node{
+		ObjectMeta: metav1.ObjectMeta{Name: "node1"},
+		Status: corev1.NodeStatus{
+			Addresses: []corev1.NodeAddress{
+				{Type: corev1.NodeHostName, Address: hostName},
+				{Type: corev1.NodeInternalIP, Address: addr},
+			},
+			Conditions: []corev1.NodeCondition{
+				{Type: corev1.NodeReady},
+			},
+		},
+	}
+	if ready {
+		res.Status.Conditions[0].Status = corev1.ConditionTrue
+	} else {
+		res.Status.Conditions[0].Status = corev1.ConditionFalse
+	}
+	return res
+}
+
+var _ = Describe("Summary Source Provider", func() {
+	var (
+		nodeLister *fakeNodeLister
+		nodeAddrs  []string
+		provider   sources.MetricSourceProvider
+		fakeClient *fakeKubeletClient
+	)
+	BeforeEach(func() {
+		nodeLister = &fakeNodeLister{
+			nodes: []*corev1.Node{
+				makeNode("node1", "node1.somedomain", "10.0.1.2", true),
+				makeNode("node-no-host", "", "10.0.1.3", true),
+				makeNode("node3", "node3.somedomain", "10.0.1.4", false),
+				makeNode("node4", "node4.somedomain", "10.0.1.5", true),
+			},
+		}
+		nodeAddrs = []string{
+			"10.0.1.2",
+			"10.0.1.3",
+			"10.0.1.4",
+			"10.0.1.5",
+		}
+		fakeClient = &fakeKubeletClient{}
+		addrResolver := NewPriorityNodeAddressResolver(DefaultAddressTypePriority)
+		provider = NewSummaryProvider(nodeLister, fakeClient, addrResolver)
+	})
+
+	It("should return a metrics source for all nodes", func() {
+		By("listing the sources")
+		sources, err := provider.GetMetricSources()
+		Expect(err).To(Succeed())
+
+		By("verifying that a source is present for each node")
+		nodeNames := nodeNames(nodeLister.nodes, nodeAddrs)
+		sourceNames := make([]string, len(nodeNames))
+		for i, src := range sources {
+			sourceNames[i] = src.Name()
+		}
+		Expect(sourceNames).To(Equal(nodeNames))
+	})
+
+	It("should continue on error fetching node information for a particular node", func() {
+		By("deleting the IP of a node")
+		nodeLister.nodes[0].Status.Addresses = nil
+
+		By("listing the sources")
+		sources, err := provider.GetMetricSources()
+		Expect(err).To(HaveOccurred())
+
+		By("verifying that a source is present for each node")
+		nodeNames := nodeNames(nodeLister.nodes, nodeAddrs)
+		sourceNames := make([]string, len(nodeNames[1:]))
+		for i, src := range sources {
+			sourceNames[i] = src.Name()
+		}
+		// skip the bad node (the first one)
+		Expect(sourceNames).To(Equal(nodeNames[1:]))
+	})
+
+	It("should gracefully handle list errors", func() {
+		By("setting a fake error from the lister")
+		nodeLister.listErr = fmt.Errorf("something went wrong, expectedly")
+
+		By("listing the sources")
+		_, err := provider.GetMetricSources()
+		Expect(err).To(HaveOccurred())
+	})
+
+	Describe("when choosing node addresses", func() {
+		JustBeforeEach(func() {
+			// set up the metrics so we can call collect safely
+			fakeClient.metrics = &stats.Summary{
+				Node: stats.NodeStats{
+					CPU:    cpuStats(100, time.Now()),
+					Memory: memStats(200, time.Now()),
+				},
+			}
+		})
+
+		It("should prefer addresses according to the order of the types first", func() {
+			By("setting the first node to have multiple addresses and setting all nodes to ready")
+			nodeLister.nodes[0].Status.Addresses = []corev1.NodeAddress{
+				{Type: DefaultAddressTypePriority[3], Address: "skip-val1"},
+				{Type: DefaultAddressTypePriority[2], Address: "skip-val2"},
+				{Type: DefaultAddressTypePriority[1], Address: "correct-val"},
+			}
+			for _, node := range nodeLister.nodes {
+				node.Status.Conditions = []corev1.NodeCondition{
+					{Type: corev1.NodeReady, Status: corev1.ConditionTrue},
+				}
+			}
+
+			By("listing all sources")
+			srcs, err := provider.GetMetricSources()
+			Expect(err).NotTo(HaveOccurred())
+
+			By("making sure that the first source scrapes from the correct location")
+			_, err = srcs[0].Collect(context.Background())
+			Expect(err).NotTo(HaveOccurred())
+			Expect(fakeClient.lastHost).To(Equal("correct-val"))
+		})
+
+		It("should prefer the first address that matches within a given type", func() {
+			By("setting the first node to have multiple addresses and setting all nodes to ready")
+			nodeLister.nodes[0].Status.Addresses = []corev1.NodeAddress{
+				{Type: DefaultAddressTypePriority[1], Address: "skip-val1"},
+				{Type: DefaultAddressTypePriority[0], Address: "correct-val"},
+				{Type: DefaultAddressTypePriority[1], Address: "skip-val2"},
+				{Type: DefaultAddressTypePriority[0], Address: "second-val"},
+			}
+			for _, node := range nodeLister.nodes {
+				node.Status.Conditions = []corev1.NodeCondition{
+					{Type: corev1.NodeReady, Status: corev1.ConditionTrue},
+				}
+			}
+
+			By("listing all sources")
+			srcs, err := provider.GetMetricSources()
+			Expect(err).NotTo(HaveOccurred())
+
+			By("making sure that the first source scrapes from the correct location")
+			_, err = srcs[0].Collect(context.Background())
+			Expect(err).NotTo(HaveOccurred())
+			Expect(fakeClient.lastHost).To(Equal("correct-val"))
+		})
+
+		It("should return an error if no preferred addresses are found", func() {
+			By("wiping out the addresses of one of the nodes and setting all nodes to ready")
+			nodeLister.nodes[0].Status.Addresses = nil
+			for _, node := range nodeLister.nodes {
+				node.Status.Conditions = []corev1.NodeCondition{
+					{Type: corev1.NodeReady, Status: corev1.ConditionTrue},
+				}
+			}
+
+			By("asking for source providers for all nodes")
+			_, err := provider.GetMetricSources()
+			Expect(err).To(HaveOccurred())
+		})
+	})
+})