implement readiness

Signed-off-by: Miek Gieben <miek@miek.nl>

plugin/traffic/README.md

@@ -40,7 +40,8 @@ traffic TO...
 
 This enabled the *traffic* plugin, with a default node id of `coredns` and no TLS.
 
-*  **TO...** are the Envoy control plane endpoint to connect to. This must start with `grpc://`.
+*  **TO...** are the Envoy control plane endpoint to connect to. This must start with `grpc://`. The
+  port number defaults to 443.
 
 The extended syntax is available is you want more control.
 
@@ -81,7 +82,8 @@ What metrics should we do? If any? Number of clusters? Number of endpoints and h
 
 ## Ready
 
-Should this plugin implement readiness?
+This plugin report readiness to the ready plugin. This will happen after a gRPC stream has been
+established to an upstream.
 
 ## Examples
 
@@ -123,7 +125,6 @@ Multiple **TO** addresses is not implemented.
 ## TODO
 
 * metrics?
-* more and better testing
 * credentials (other than TLS) - how/what?
 * is the protocol correctly implemented? Should we not have a 10s tick, but wait for responses from
   the control plane?

plugin/traffic/ready.go

@@ -0,0 +1,4 @@
+package traffic
+
+// Ready implements the ready.Readiness interface.
+func (t *Traffic) Ready() bool { return t.c.HasSynced() }

plugin/traffic/setup.go

@@ -117,6 +117,7 @@ func parseTraffic(c *caddy.Controller) (*Traffic, error) {
 	if t.c, err = xds.New(toHosts[0], node, opts...); err != nil {
 		return nil, err
 	}
+	t.to = toHosts[0]
 
 	return t, nil
 }

plugin/traffic/setup_test.go

@@ -7,12 +7,10 @@ import (
 )
 
 func TestSetup(t *testing.T) {
-	/*
-		c := caddy.NewTestController("dns", `traffic grpc://bla`)
-		if err := setup(c); err != nil {
-			t.Fatalf("Test 1, expected no errors, but got: %q", err)
-		}
-	*/
+	c := caddy.NewTestController("dns", `traffic grpc://127.0.0.1`)
+	if err := setup(c); err != nil {
+		t.Fatalf("Test 1, expected no errors, but got: %q", err)
+	}
 }
 
 func TestParseTraffic(t *testing.T) {

plugin/traffic/xds/client.go

@@ -52,14 +52,15 @@ type adsStream adsgrpc.AggregatedDiscoveryService_StreamAggregatedResourcesClien
 type Client struct {
 	cc          *grpc.ClientConn
 	ctx         context.Context
-	assignments *assignment // assignments contains the current clusters and endpoints.
 	node        *corepb.Node
 	cancel      context.CancelFunc
 	stop        chan struct{}
-	mu          sync.RWMutex
-
-	version map[string]string
-	nonce   map[string]string
+	to          string       // upstream hosts, mostly here for logging purposes
+	mu          sync.RWMutex // protects everything below
+	assignments *assignment  // assignments contains the current clusters and endpoints
+	version     map[string]string
+	nonce       map[string]string
+	synced      bool // true when we first successfully got a stream
 }
 
 // New returns a new client that's dialed to addr using node as the local identifier.
@@ -92,6 +93,7 @@ func (c *Client) Stop() error { c.cancel(); return c.cc.Close() }
 
 // Run starts all goroutines and gathers the clusters and endpoint information from the upstream manager.
 func (c *Client) Run() {
+	first := true
 	for {
 		select {
 		case <-c.ctx.Done():
@@ -107,6 +109,12 @@ func (c *Client) Run() {
 			continue
 		}
 
+		if first {
+			log.Info("gRPC stream established to %q", c.to)
+			c.setSynced()
+			first = false
+		}
+
 		done := make(chan struct{})
 		go func() {
 			if err := c.clusterDiscovery(stream, c.Version(cdsURL), c.Nonce(cdsURL), []string{}); err != nil {
@@ -128,7 +136,7 @@ func (c *Client) Run() {
 			}
 		}()
 
-		if err := c.Receive(stream); err != nil {
+		if err := c.receive(stream); err != nil {
 			log.Warning(err)
 		}
 		close(done)
@@ -159,8 +167,8 @@ func (c *Client) endpointDiscovery(stream adsStream, version, nonce string, clus
 	return stream.Send(req)
 }
 
-// Receive receives from the stream, it handled both cluster and endpoint DiscoveryResponses.
-func (c *Client) Receive(stream adsStream) error {
+// receive receives from the stream, it handled both cluster and endpoint DiscoveryResponses.
+func (c *Client) receive(stream adsStream) error {
 	for {
 		resp, err := stream.Recv()
 		if err != nil {
@@ -182,7 +190,7 @@ func (c *Client) Receive(stream adsStream) error {
 				}
 				a.SetClusterLoadAssignment(cluster.GetName(), nil)
 			}
-			log.Debugf("Cluster discovery processed with %d resources, version %q and nonce %q, clusters: %v", len(resp.GetResources()), c.Version(cdsURL), c.Nonce(cdsURL), a.clusters())
+			log.Debugf("Cluster discovery processed with %d resources, version %q and nonce %q", len(resp.GetResources()), c.Version(cdsURL), c.Nonce(cdsURL))
 			// set our local administration and ack the reply. Empty version would signal NACK.
 			c.SetNonce(cdsURL, resp.GetNonce())
 			c.SetVersion(cdsURL, resp.GetVersionInfo())
@@ -206,7 +214,7 @@ func (c *Client) Receive(stream adsStream) error {
 				}
 				c.assignments.SetClusterLoadAssignment(cla.GetClusterName(), cla)
 			}
-			log.Debugf("Endpoint discovery processed with %d resources, version %q and nonce %q, clusters: %v", len(resp.GetResources()), c.Version(edsURL), c.Nonce(edsURL), c.assignments.clusters())
+			log.Debugf("Endpoint discovery processed with %d resources, version %q and nonce %q", len(resp.GetResources()), c.Version(edsURL), c.Nonce(edsURL))
 			// set our local administration and ack the reply. Empty version would signal NACK.
 			c.SetNonce(edsURL, resp.GetNonce())
 			c.SetVersion(edsURL, resp.GetVersionInfo())

plugin/traffic/xds/fields.go

@@ -1,37 +1,57 @@
 package xds
 
+// Assignment returns the current assignment map.
 func (c *Client) Assignments() *assignment {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 	return c.assignments
 }
 
+// SetAssignment sets the assignment map.
 func (c *Client) SetAssignments(a *assignment) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	c.assignments = a
 }
 
+// Version returns the last version seen from the API for this typeURL.
 func (c *Client) Version(typeURL string) string {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 	return c.version[typeURL]
 }
 
+// SetVersion sets the version for this typeURL.
 func (c *Client) SetVersion(typeURL, a string) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	c.version[typeURL] = a
 }
 
+// Nonce returns the last nonce seen from the API for this typeURL.
 func (c *Client) Nonce(typeURL string) string {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 	return c.nonce[typeURL]
 }
 
+// SetNonce sets the nonce. for this typeURL.
 func (c *Client) SetNonce(typeURL, n string) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	c.nonce[typeURL] = n
 }
+
+// SetSynced sets the synced boolean to true.
+func (c *Client) setSynced() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.synced = true
+}
+
+// Synced return true if the clients has synced.
+func (c *Client) HasSynced() bool {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return c.synced
+}