Add edge routing and health check RPCs (Phase 2)

New agent RPCs for v2 multi-node orchestration: - SetupEdgeRoute: provisions TLS cert from Metacrypt, resolves backend hostname to Tailnet IP, validates it's in 100.64.0.0/10, registers L7 route in mc-proxy. Rejects backend_tls=false. - RemoveEdgeRoute: removes mc-proxy route, cleans up TLS cert, removes registry entry. - ListEdgeRoutes: returns all edge routes with cert serial/expiry. - HealthCheck: returns agent health and container count. New database table (migration 4): edge_routes stores hostname, backend info, and cert paths for persistence across agent restarts. ProxyRouter gains CertPath/KeyPath helpers for consistent cert path construction. Security: - Backend hostname must resolve to a Tailnet IP (100.64.0.0/10) - backend_tls=false is rejected (no cleartext to backends) - Cert provisioning failure fails the setup (no route to missing cert) Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-02 13:13:10 -07:00
parent fa8ba6fac1
commit 714320c018
7 changed files with 1069 additions and 56 deletions
--- a/internal/agent/edge_rpc.go
+++ b/internal/agent/edge_rpc.go
@@ -0,0 +1,196 @@
+package agent
+
+import (
+	"context"
+	"crypto/x509"
+	"encoding/pem"
+	"fmt"
+	"net"
+	"os"
+	"time"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+
+	mcpv1 "git.wntrmute.dev/mc/mcp/gen/mcp/v1"
+	mcproxy "git.wntrmute.dev/mc/mc-proxy/client/mcproxy"
+	"git.wntrmute.dev/mc/mcp/internal/registry"
+)
+
+// SetupEdgeRoute provisions a TLS cert and registers an mc-proxy route for a
+// public hostname. Called by the master on edge nodes.
+func (a *Agent) SetupEdgeRoute(ctx context.Context, req *mcpv1.SetupEdgeRouteRequest) (*mcpv1.SetupEdgeRouteResponse, error) {
+	a.Logger.Info("SetupEdgeRoute", "hostname", req.GetHostname(),
+		"backend_hostname", req.GetBackendHostname(), "backend_port", req.GetBackendPort())
+
+	// Validate required fields.
+	if req.GetHostname() == "" {
+		return nil, status.Error(codes.InvalidArgument, "hostname is required")
+	}
+	if req.GetBackendHostname() == "" {
+		return nil, status.Error(codes.InvalidArgument, "backend_hostname is required")
+	}
+	if req.GetBackendPort() == 0 {
+		return nil, status.Error(codes.InvalidArgument, "backend_port is required")
+	}
+	if !req.GetBackendTls() {
+		return nil, status.Error(codes.InvalidArgument, "backend_tls must be true")
+	}
+
+	if a.Proxy == nil {
+		return nil, status.Error(codes.FailedPrecondition, "mc-proxy not configured")
+	}
+
+	// Resolve the backend hostname to a Tailnet IP.
+	ips, err := net.LookupHost(req.GetBackendHostname())
+	if err != nil || len(ips) == 0 {
+		return nil, status.Errorf(codes.InvalidArgument, "cannot resolve backend_hostname %q: %v", req.GetBackendHostname(), err)
+	}
+	backendIP := ips[0]
+
+	// Validate the resolved IP is a Tailnet address (100.64.0.0/10).
+	ip := net.ParseIP(backendIP)
+	if ip == nil {
+		return nil, status.Errorf(codes.InvalidArgument, "resolved IP %q is not valid", backendIP)
+	}
+	_, tailnet, _ := net.ParseCIDR("100.64.0.0/10")
+	if !tailnet.Contains(ip) {
+		return nil, status.Errorf(codes.InvalidArgument, "resolved IP %s is not a Tailnet address", backendIP)
+	}
+
+	backend := fmt.Sprintf("%s:%d", backendIP, req.GetBackendPort())
+
+	// Provision TLS cert for the public hostname if cert provisioner is available.
+	certPath := ""
+	keyPath := ""
+	if a.Certs != nil {
+		if err := a.Certs.EnsureCert(ctx, req.GetHostname(), []string{req.GetHostname()}); err != nil {
+			return nil, status.Errorf(codes.Internal, "provision cert for %s: %v", req.GetHostname(), err)
+		}
+		certPath = a.Proxy.CertPath(req.GetHostname())
+		keyPath = a.Proxy.KeyPath(req.GetHostname())
+	} else {
+		// No cert provisioner — check if certs already exist on disk.
+		certPath = a.Proxy.CertPath(req.GetHostname())
+		keyPath = a.Proxy.KeyPath(req.GetHostname())
+		if _, err := os.Stat(certPath); err != nil {
+			return nil, status.Errorf(codes.FailedPrecondition, "no cert provisioner and cert not found at %s", certPath)
+		}
+	}
+
+	// Register the L7 route in mc-proxy.
+	route := mcproxy.Route{
+		Hostname:   req.GetHostname(),
+		Backend:    backend,
+		Mode:       "l7",
+		TLSCert:    certPath,
+		TLSKey:     keyPath,
+		BackendTLS: true,
+	}
+	if err := a.Proxy.AddRoute(ctx, ":443", route); err != nil {
+		return nil, status.Errorf(codes.Internal, "add mc-proxy route: %v", err)
+	}
+
+	// Persist the edge route in the registry.
+	if err := registry.CreateEdgeRoute(a.DB, req.GetHostname(), req.GetBackendHostname(), int(req.GetBackendPort()), certPath, keyPath); err != nil {
+		a.Logger.Warn("failed to persist edge route", "hostname", req.GetHostname(), "err", err)
+	}
+
+	a.Logger.Info("edge route established",
+		"hostname", req.GetHostname(), "backend", backend, "cert", certPath)
+
+	return &mcpv1.SetupEdgeRouteResponse{}, nil
+}
+
+// RemoveEdgeRoute removes an mc-proxy route and cleans up the TLS cert for a
+// public hostname. Called by the master on edge nodes.
+func (a *Agent) RemoveEdgeRoute(ctx context.Context, req *mcpv1.RemoveEdgeRouteRequest) (*mcpv1.RemoveEdgeRouteResponse, error) {
+	a.Logger.Info("RemoveEdgeRoute", "hostname", req.GetHostname())
+
+	if req.GetHostname() == "" {
+		return nil, status.Error(codes.InvalidArgument, "hostname is required")
+	}
+
+	if a.Proxy == nil {
+		return nil, status.Error(codes.FailedPrecondition, "mc-proxy not configured")
+	}
+
+	// Remove the mc-proxy route.
+	if err := a.Proxy.RemoveRoute(ctx, ":443", req.GetHostname()); err != nil {
+		a.Logger.Warn("remove mc-proxy route", "hostname", req.GetHostname(), "err", err)
+		// Continue — clean up cert and registry even if route removal fails.
+	}
+
+	// Remove the TLS cert.
+	if a.Certs != nil {
+		if err := a.Certs.RemoveCert(req.GetHostname()); err != nil {
+			a.Logger.Warn("remove cert", "hostname", req.GetHostname(), "err", err)
+		}
+	}
+
+	// Remove from registry.
+	if err := registry.DeleteEdgeRoute(a.DB, req.GetHostname()); err != nil {
+		a.Logger.Warn("delete edge route from registry", "hostname", req.GetHostname(), "err", err)
+	}
+
+	a.Logger.Info("edge route removed", "hostname", req.GetHostname())
+	return &mcpv1.RemoveEdgeRouteResponse{}, nil
+}
+
+// ListEdgeRoutes returns all edge routes managed by this agent.
+func (a *Agent) ListEdgeRoutes(_ context.Context, _ *mcpv1.ListEdgeRoutesRequest) (*mcpv1.ListEdgeRoutesResponse, error) {
+	a.Logger.Debug("ListEdgeRoutes called")
+
+	routes, err := registry.ListEdgeRoutes(a.DB)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "list edge routes: %v", err)
+	}
+
+	resp := &mcpv1.ListEdgeRoutesResponse{}
+	for _, r := range routes {
+		er := &mcpv1.EdgeRoute{
+			Hostname:        r.Hostname,
+			BackendHostname: r.BackendHostname,
+			BackendPort:     int32(r.BackendPort), //nolint:gosec // port is a small positive integer
+		}
+
+		// Read cert metadata if available.
+		if r.TLSCert != "" {
+			if certData, readErr := os.ReadFile(r.TLSCert); readErr == nil { //nolint:gosec // path from registry, not user input
+				if block, _ := pem.Decode(certData); block != nil {
+					if cert, parseErr := x509.ParseCertificate(block.Bytes); parseErr == nil {
+						er.CertSerial = cert.SerialNumber.String()
+						er.CertExpires = cert.NotAfter.UTC().Format(time.RFC3339)
+					}
+				}
+			}
+		}
+
+		resp.Routes = append(resp.Routes, er)
+	}
+
+	return resp, nil
+}
+
+// HealthCheck returns the agent's health status. Called by the master when
+// heartbeats are missed.
+func (a *Agent) HealthCheck(_ context.Context, _ *mcpv1.HealthCheckRequest) (*mcpv1.HealthCheckResponse, error) {
+	a.Logger.Debug("HealthCheck called")
+
+	st := "healthy"
+	containers := int32(0)
+
+	// Count running containers if the runtime is available.
+	if a.Runtime != nil {
+		if list, err := a.Runtime.List(context.Background()); err == nil {
+			containers = int32(len(list)) //nolint:gosec // container count is small
+		} else {
+			st = "degraded"
+		}
+	}
+
+	return &mcpv1.HealthCheckResponse{
+		Status:     st,
+		Containers: containers,
+	}, nil
+}