WIP: Query sentries for thier addresses upon validator registration

go/worker/common/config.go

@@ -1,13 +1,16 @@
 package common
 
 import (
+	"crypto/x509"
 	"fmt"
 
 	flag "github.com/spf13/pflag"
 	"github.com/spf13/viper"
 
 	"github.com/oasislabs/oasis-core/go/common"
 	"github.com/oasislabs/oasis-core/go/common/crypto/signature"
+	memorySigner "github.com/oasislabs/oasis-core/go/common/crypto/signature/signers/memory"
+	"github.com/oasislabs/oasis-core/go/common/identity"
 	"github.com/oasislabs/oasis-core/go/common/logging"
 	"github.com/oasislabs/oasis-core/go/common/node"
 	"github.com/oasislabs/oasis-core/go/worker/common/configparser"
@@ -19,6 +22,12 @@ var (
 
 	cfgClientAddresses = "worker.client.addresses"
 
+	// CfgSentryAddresses configures addresses of the worker's sentry nodes.
+	CfgSentryAddresses = "worker.sentry.addresses"
+	// CfgSentryCertFiles configures paths to certificates of the worker's
+	// sentry nodes.
+	CfgSentryCertFiles = "worker.sentry.cert_files"
+
 	// CfgRuntimeID configures the worker runtime ID(s).
 	CfgRuntimeID = "worker.runtime.id"
 	// CfgRuntimeBackend configures the runtime backend.
@@ -34,9 +43,11 @@ var (
 
 // Config contains common worker config.
 type Config struct { // nolint: maligned
-	ClientPort      uint16
-	ClientAddresses []node.Address
-	Runtimes        []signature.PublicKey
+	ClientPort         uint16
+	ClientAddresses    []node.Address
+	SentryAddresses    []node.Address
+	SentryCertificates []*x509.Certificate
+	Runtimes           []signature.PublicKey
 
 	// RuntimeHost contains configuration for a worker that hosts
 	// runtimes. It may be nil if the worker is not configured to
@@ -91,16 +102,42 @@ func newConfig() (*Config, error) {
 	if err != nil {
 		return nil, err
 	}
+	// Parse sentry nodes' addresses.
+	sentryAddresses, err := configparser.ParseAddressList(viper.GetStringSlice(CfgSentryAddresses))
+	if err != nil {
+		return nil, err
+	}
+	// Parse sentry nodes' certificate files.
+	sentryCertFiles := viper.GetStringSlice(CfgSentryCertFiles)
+	// TODO: Check if the number of sentry addresses correspond to the number of sentry cert files.
+	sentryCerts := []*x509.Certificate{}
+	for _, certFile := range sentryCertFiles {
+		ident, err := identity.Load(certFile, memorySigner.NewFactory())
+		if err != nil {
+			return nil, err
+		}
+		if len(ident.TLSCertificate.Certificate) != 1 {
+			return nil, fmt.Errorf("sentry certificate file %v should contain exactly 1 certificate in the chain", certFile)
+		}
+		x509Cert, err := x509.ParseCertificate(ident.TLSCertificate.Certificate[0])
+		if err != nil {
+			return nil, err
+		}
+		sentryCerts = append(sentryCerts, x509Cert)
+	}
+
 	runtimes, err := configparser.GetRuntimes(viper.GetStringSlice(CfgRuntimeID))
 	if err != nil {
 		return nil, err
 	}
 
 	cfg := Config{
-		ClientPort:      uint16(viper.GetInt(CfgClientPort)),
-		ClientAddresses: clientAddresses,
-		Runtimes:        runtimes,
-		logger:          logging.GetLogger("worker/config"),
+		ClientPort:         uint16(viper.GetInt(CfgClientPort)),
+		ClientAddresses:    clientAddresses,
+		SentryAddresses:    sentryAddresses,
+		SentryCertificates: sentryCerts,
+		Runtimes:           runtimes,
+		logger:             logging.GetLogger("worker/config"),
 	}
 
 	// Check if runtime host is configured for the runtimes.

go/worker/registration/registration.go

@@ -20,6 +20,7 @@ import (
 	epochtime "github.com/oasislabs/oasis-core/go/epochtime/api"
 	"github.com/oasislabs/oasis-core/go/oasis-node/cmd/common/flags"
 	registry "github.com/oasislabs/oasis-core/go/registry/api"
+	sentryClient "github.com/oasislabs/oasis-core/go/sentry/client"
 	workerCommon "github.com/oasislabs/oasis-core/go/worker/common"
 	"github.com/oasislabs/oasis-core/go/worker/common/p2p"
 )
@@ -225,9 +226,33 @@ func (r *Registration) registerNode(epoch epochtime.EpochTime) error {
 }
 
 func (r *Registration) consensusValidatorHook(n *node.Node) error {
-	addrs, err := r.consensus.GetAddresses()
-	if err != nil {
-		return errors.Wrap(err, "worker/registration: failed to get consensus validator addresses")
+	sentryAddrs := r.workerCommonCfg.SentryAddresses
+	addrs := []node.Address{}
+	if len(sentryAddrs) > 0 {
+		sentryCerts := r.workerCommonCfg.SentryCertificates
+		// Query sentry nodes for their addresses
+		for i, sentryAddr := range sentryAddrs {
+			client, err := sentryClient.New(sentryAddr, sentryCerts[i], r.identity)
+			if err != nil {
+				r.logger.Error("failed to create sentry client to node",
+					"err", err,
+					"sentry_node_addr", addr,
+				)
+			}
+			sentryPubAddrs, err := client.GetPublicAddresses()
+			if err != nil {
+				// XXX: Should this be a warning instead of an error?
+				r.logger.Error("failed to obtain public addresses of a sentry node")
+				return err
+			}
+			addrs = append(addrs, sentryPubAddrs)
+			// TODO: Close the client.
+		}
+	} else {
+		addrs, err := r.consensus.GetAddresses()
+		if err != nil {
+			return errors.Wrap(err, "worker/registration: failed to get consensus validator addresses")
+		}
 	}
 
 	if len(addrs) == 0 {