Allow disabling controls in probes

experimental/demoprobe/main.go

@@ -31,7 +31,7 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
-	rp := appclient.NewReportPublisher(client)
+	rp := appclient.NewReportPublisher(client, false)
 
 	rand.Seed(time.Now().UnixNano())
 	for range time.Tick(*publishInterval) {

experimental/fixprobe/main.go

@@ -54,7 +54,7 @@ func main() {
 		log.Fatal(err)
 	}
 
-	rp := appclient.NewReportPublisher(client)
+	rp := appclient.NewReportPublisher(client, false)
 	for range time.Tick(*publishInterval) {
 		rp.Publish(fixedReport)
 	}

probe/appclient/app_client_internal_test.go

@@ -116,7 +116,7 @@ func TestAppClientPublish(t *testing.T) {
 	defer p.Stop()
 
 	// First few reports might be dropped as the client is spinning up.
-	rp := NewReportPublisher(p)
+	rp := NewReportPublisher(p, false)
 	for i := 0; i < 10; i++ {
 		if err := rp.Publish(rpt); err != nil {
 			t.Error(err)
@@ -208,7 +208,7 @@ func TestStop(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	rp := NewReportPublisher(p)
+	rp := NewReportPublisher(p, false)
 
 	// Make sure the app received our report and is stuck
 	for done := false; !done; {

probe/appclient/multi_client.go

@@ -23,11 +23,12 @@ type ClientFactory func(string, string) (AppClient, error)
 type multiClient struct {
 	clientFactory ClientFactory
 
-	mtx     sync.Mutex
-	sema    semaphore
-	clients map[string]AppClient     // holds map from app id -> client
-	ids     map[string]report.IDList // holds map from hostname -> app ids
-	quit    chan struct{}
+	mtx        sync.Mutex
+	sema       semaphore
+	clients    map[string]AppClient     // holds map from app id -> client
+	ids        map[string]report.IDList // holds map from hostname -> app ids
+	quit       chan struct{}
+	noControls bool
 }
 
 type clientTuple struct {
@@ -53,14 +54,15 @@ type MultiAppClient interface {
 }
 
 // NewMultiAppClient creates a new MultiAppClient.
-func NewMultiAppClient(clientFactory ClientFactory) MultiAppClient {
+func NewMultiAppClient(clientFactory ClientFactory, noControls bool) MultiAppClient {
 	return &multiClient{
 		clientFactory: clientFactory,
 
-		sema:    newSemaphore(maxConcurrentGET),
-		clients: map[string]AppClient{},
-		ids:     map[string]report.IDList{},
-		quit:    make(chan struct{}),
+		sema:       newSemaphore(maxConcurrentGET),
+		clients:    map[string]AppClient{},
+		ids:        map[string]report.IDList{},
+		quit:       make(chan struct{}),
+		noControls: noControls,
 	}
 }
 
@@ -100,11 +102,11 @@ func (c *multiClient) Set(hostname string, endpoints []string) {
 	hostIDs := report.MakeIDList()
 	for tuple := range clients {
 		hostIDs = hostIDs.Add(tuple.ID)
-
-		_, ok := c.clients[tuple.ID]
-		if !ok {
+		if _, ok := c.clients[tuple.ID]; !ok {
 			c.clients[tuple.ID] = tuple.AppClient
-			tuple.AppClient.ControlConnection()
+			if !c.noControls {
+				tuple.AppClient.ControlConnection()
+			}
 		}
 	}
 	c.ids[hostname] = hostIDs

probe/appclient/multi_client_test.go

@@ -67,7 +67,7 @@ func TestMultiClient(t *testing.T) {
 		}
 	)
 
-	mp := appclient.NewMultiAppClient(factory)
+	mp := appclient.NewMultiAppClient(factory, false)
 	defer mp.Stop()
 
 	// Add two hostnames with overlapping apps, check we don't add the same app twice
@@ -89,7 +89,7 @@ func TestMultiClient(t *testing.T) {
 }
 
 func TestMultiClientPublish(t *testing.T) {
-	mp := appclient.NewMultiAppClient(factory)
+	mp := appclient.NewMultiAppClient(factory, false)
 	defer mp.Stop()
 
 	sum := func() int { return a1.publish + a2.publish + b2.publish + b3.publish }

probe/appclient/report_publisher.go

@@ -8,18 +8,25 @@ import (
 // A ReportPublisher uses a buffer pool to serialise reports, which it
 // then passes to a publisher
 type ReportPublisher struct {
-	publisher Publisher
+	publisher  Publisher
+	noControls bool
 }
 
 // NewReportPublisher creates a new report publisher
-func NewReportPublisher(publisher Publisher) *ReportPublisher {
+func NewReportPublisher(publisher Publisher, noControls bool) *ReportPublisher {
 	return &ReportPublisher{
-		publisher: publisher,
+		publisher:  publisher,
+		noControls: noControls,
 	}
 }
 
 // Publish serialises and compresses a report, then passes it to a publisher
 func (p *ReportPublisher) Publish(r report.Report) error {
+	if p.noControls {
+		r.WalkTopologies(func(t *report.Topology) {
+			t.Controls = report.Controls{}
+		})
+	}
 	buf := &bytes.Buffer{}
 	r.WriteBinary(buf)
 	return p.publisher.Publish(buf)

probe/probe.go

@@ -68,11 +68,12 @@ type Ticker interface {
 func New(
 	spyInterval, publishInterval time.Duration,
 	publisher appclient.Publisher,
+	noControls bool,
 ) *Probe {
 	result := &Probe{
 		spyInterval:     spyInterval,
 		publishInterval: publishInterval,
-		publisher:       appclient.NewReportPublisher(publisher),
+		publisher:       appclient.NewReportPublisher(publisher, noControls),
 		quit:            make(chan struct{}),
 		spiedReports:    make(chan report.Report, reportBufferSize),
 		shortcutReports: make(chan report.Report, reportBufferSize),

probe/probe_internal_test.go

@@ -19,7 +19,7 @@ func TestApply(t *testing.T) {
 		endpointNode   = report.MakeNodeWith(endpointNodeID, map[string]string{"5": "6"})
 	)
 
-	p := New(0, 0, nil)
+	p := New(0, 0, nil, false)
 	p.AddTagger(NewTopologyTagger())
 
 	r := report.MakeReport()
@@ -95,7 +95,7 @@ func TestProbe(t *testing.T) {
 
 	pub := mockPublisher{make(chan report.Report, 10)}
 
-	p := New(10*time.Millisecond, 100*time.Millisecond, pub)
+	p := New(10*time.Millisecond, 100*time.Millisecond, pub, false)
 	p.AddReporter(mockReporter{want})
 	p.Start()
 	defer p.Stop()

prog/main.go

@@ -67,6 +67,7 @@ type probeFlags struct {
 	logLevel        string
 	resolver        string
 	noApp           bool
+	noControls      bool
 
 	useConntrack bool // Use conntrack for endpoint topo
 	spyProcs     bool // Associate endpoints with processes (must be root)
@@ -145,6 +146,7 @@ func main() {
 	flag.DurationVar(&flags.probe.publishInterval, "probe.publish.interval", 3*time.Second, "publish (output) interval")
 	flag.DurationVar(&flags.probe.spyInterval, "probe.spy.interval", time.Second, "spy (scan) interval")
 	flag.StringVar(&flags.probe.pluginsRoot, "probe.plugins.root", "/var/run/scope/plugins", "Root directory to search for plugins")
+	flag.BoolVar(&flags.probe.noControls, "probe.no-controls", false, "Disable controls (read-only mode)")
 
 	flag.BoolVar(&flags.probe.insecure, "probe.insecure", false, "(SSL) explicitly allow \"insecure\" SSL connections and transfers")
 	flag.StringVar(&flags.probe.resolver, "probe.resolver", "", "IP address & port of resolver to use.  Default is to use system resolver.")

prog/probe.go

@@ -113,12 +113,13 @@ func probeMain(flags probeFlags) {
 		ProbeID:      probeID,
 		Insecure:     flags.insecure,
 	}
-	clients := appclient.NewMultiAppClient(func(hostname, endpoint string) (appclient.AppClient, error) {
+	clientFactory := func(hostname, endpoint string) (appclient.AppClient, error) {
 		return appclient.NewAppClient(
 			probeConfig, hostname, endpoint,
 			xfer.ControlHandlerFunc(controls.HandleControlRequest),
 		)
-	})
+	}
+	clients := appclient.NewMultiAppClient(clientFactory, flags.noControls)
 	defer clients.Stop()
 
 	dnsLookupFn := net.LookupIP
@@ -128,7 +129,7 @@ func probeMain(flags probeFlags) {
 	resolver := appclient.NewResolver(targets, dnsLookupFn, clients.Set)
 	defer resolver.Stop()
 
-	p := probe.New(flags.spyInterval, flags.publishInterval, clients)
+	p := probe.New(flags.spyInterval, flags.publishInterval, clients, flags.noControls)
 
 	hostReporter := host.NewReporter(hostID, hostName, probeID, version, clients)
 	defer hostReporter.Stop()

report/report.go

@@ -197,18 +197,26 @@ func (r Report) Merge(other Report) Report {
 
 // Topologies returns a slice of Topologies in this report
 func (r Report) Topologies() []Topology {
-	return []Topology{
-		r.Endpoint,
-		r.Process,
-		r.Container,
-		r.ContainerImage,
-		r.Pod,
-		r.Service,
-		r.Deployment,
-		r.ReplicaSet,
-		r.Host,
-		r.Overlay,
-	}
+	result := []Topology{}
+	r.WalkTopologies(func(t *Topology) {
+		result = append(result, *t)
+	})
+	return result
+}
+
+// WalkTopologies iterates through the Topologies of the report,
+// potentially modifying them
+func (r *Report) WalkTopologies(f func(*Topology)) {
+	f(&r.Endpoint)
+	f(&r.Process)
+	f(&r.Container)
+	f(&r.ContainerImage)
+	f(&r.Pod)
+	f(&r.Service)
+	f(&r.Deployment)
+	f(&r.ReplicaSet)
+	f(&r.Host)
+	f(&r.Overlay)
 }
 
 // Topology gets a topology by name