metropolis/node/core/metrics: export (controller-manager|scheduler) metrics

Change-Id: Ie61551655cbf1130bb5f5beb2923dac1aa52f868
Reviewed-on: https://review.monogon.dev/c/monogon/+/1952
Tested-by: Jenkins CI
Reviewed-by: Serge Bazanski <serge@monogon.tech>
diff --git a/metropolis/node/core/roleserve/roleserve.go b/metropolis/node/core/roleserve/roleserve.go
index 02bc510..0c486d1 100644
--- a/metropolis/node/core/roleserve/roleserve.go
+++ b/metropolis/node/core/roleserve/roleserve.go
@@ -168,6 +168,7 @@
 	s.metrics = &workerMetrics{
 		curatorConnection: &s.CuratorConnection,
 		localRoles:        &s.localRoles,
+		localControlplane: &s.localControlPlane,
 	}
 
 	return s
diff --git a/metropolis/node/core/roleserve/worker_metrics.go b/metropolis/node/core/roleserve/worker_metrics.go
index a9add88..d0c89a4 100644
--- a/metropolis/node/core/roleserve/worker_metrics.go
+++ b/metropolis/node/core/roleserve/worker_metrics.go
@@ -2,10 +2,14 @@
 
 import (
 	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
 
 	cpb "source.monogon.dev/metropolis/proto/common"
 
 	"source.monogon.dev/metropolis/node/core/metrics"
+	kpki "source.monogon.dev/metropolis/node/kubernetes/pki"
 	"source.monogon.dev/metropolis/pkg/event/memory"
 	"source.monogon.dev/metropolis/pkg/supervisor"
 
@@ -19,6 +23,7 @@
 type workerMetrics struct {
 	curatorConnection *memory.Value[*curatorConnection]
 	localRoles        *memory.Value[*cpb.NodeRoles]
+	localControlplane *memory.Value[*localControlPlane]
 }
 
 func (s *workerMetrics) run(ctx context.Context) error {
@@ -32,10 +37,53 @@
 	}
 	supervisor.Logger(ctx).Infof("Got curator connection, starting...")
 
+	lw := s.localControlplane.Watch()
+	defer lw.Close()
+	cp, err := lw.Get(ctx)
+	if err != nil {
+		return err
+	}
+
+	pki, err := kpki.FromLocalConsensus(ctx, cp.consensus)
+	if err != nil {
+		return err
+	}
+
+	// TODO(q3k): move this to IssueCertificates and replace with dedicated certificate
+	cert, key, err := pki.Certificate(ctx, kpki.Master)
+	if err != nil {
+		return fmt.Errorf("could not load certificate %q from PKI: %w", kpki.Master, err)
+	}
+	parsedKey, err := x509.ParsePKCS8PrivateKey(key)
+	if err != nil {
+		return fmt.Errorf("failed to parse key for cert %q: %w", kpki.Master, err)
+	}
+
+	caCert, _, err := pki.Certificate(ctx, kpki.IdCA)
+	if err != nil {
+		return fmt.Errorf("could not load certificate %q from PKI: %w", kpki.IdCA, err)
+	}
+	parsedCACert, err := x509.ParseCertificate(caCert)
+	if err != nil {
+		return fmt.Errorf("failed to parse cert %q: %w", kpki.IdCA, err)
+	}
+
+	rootCAs := x509.NewCertPool()
+	rootCAs.AddCert(parsedCACert)
+
+	kubeTLSConfig := &tls.Config{
+		RootCAs: rootCAs,
+		Certificates: []tls.Certificate{{
+			Certificate: [][]byte{cert},
+			PrivateKey:  parsedKey,
+		}},
+	}
+
 	svc := metrics.Service{
-		Credentials: cc.credentials,
-		Curator:     ipb.NewCuratorClient(cc.conn),
-		LocalRoles:  s.localRoles,
+		Credentials:   cc.credentials,
+		Curator:       ipb.NewCuratorClient(cc.conn),
+		LocalRoles:    s.localRoles,
+		KubeTLSConfig: kubeTLSConfig,
 	}
 	return svc.Run(ctx)
 }