From 5defc27f6314698c819b2e299f514181de46a1c7 Mon Sep 17 00:00:00 2001
From: Paul Payne <paul@payne.io>
Date: Thu, 9 Jul 2026 03:45:51 +0000
Subject: [PATCH] feat: Wire up service registration to networking
 reconciliation
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When a service is registered, updated, or deregistered, Central now
automatically regenerates HAProxy routes and dnsmasq DNS entries to
match the current set of registered services.

- L4 tcp-passthrough services (Wild Cloud) → HAProxy SNI routes
- L7 http services (Wild Works) → HAProxy Host-based reverse proxy
- All services with reach != off → dnsmasq DNS entries
- SSE events broadcast on config changes
- Reconciliation runs asynchronously (non-blocking)

This closes the loop: service registration is no longer inert — it
actually updates the networking stack.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 internal/api/v1/handlers.go |   4 ++
 internal/api/v1/helpers.go  | 107 ++++++++++++++++++++++++++++++++++++
 2 files changed, 111 insertions(+)

diff --git a/internal/api/v1/handlers.go b/internal/api/v1/handlers.go
index f9c1bf4..995ba34 100644
--- a/internal/api/v1/handlers.go
+++ b/internal/api/v1/handlers.go
@@ -82,6 +82,10 @@ func NewAPI(dataDir, version string, allowedOrigins []string) (*API, error) {
 		sseManager:     sseManager,
 	}
 
+	// Wire up service registration reconciliation: when services change,
+	// regenerate dnsmasq DNS entries and HAProxy routes.
+	api.services.SetReconcileFn(api.reconcileNetworking)
+
 	return api, nil
 }
 
diff --git a/internal/api/v1/helpers.go b/internal/api/v1/helpers.go
index 0ebc896..103d44c 100644
--- a/internal/api/v1/helpers.go
+++ b/internal/api/v1/helpers.go
@@ -2,11 +2,118 @@ package v1
 
 import (
 	"fmt"
+	"log/slog"
+	"path/filepath"
 	"time"
 
+	"github.com/wild-cloud/wild-central/internal/config"
+	"github.com/wild-cloud/wild-central/internal/haproxy"
+	"github.com/wild-cloud/wild-central/internal/services"
 	"github.com/wild-cloud/wild-central/internal/sse"
 )
 
+// reconcileNetworking reads all registered services and regenerates
+// dnsmasq DNS entries and HAProxy routes to match. Called automatically
+// whenever a service is registered, updated, or deregistered.
+func (api *API) reconcileNetworking() {
+	svcs, err := api.services.List()
+	if err != nil {
+		slog.Error("reconcile: failed to list services", "error", err)
+		return
+	}
+
+	globalConfigPath := filepath.Join(api.dataDir, "config.yaml")
+	globalCfg, err := config.LoadGlobalConfig(globalConfigPath)
+	if err != nil {
+		slog.Warn("reconcile: failed to load global config, using empty", "error", err)
+		globalCfg = &config.GlobalConfig{}
+	}
+
+	// Build HAProxy routes from registered services
+	var instanceRoutes []haproxy.InstanceRoute
+	var httpRoutes []haproxy.HTTPRoute
+
+	for _, svc := range svcs {
+		if svc.Reach == services.ReachOff {
+			continue
+		}
+
+		switch svc.Backend.Type {
+		case services.BackendTCPPassthrough:
+			instanceRoutes = append(instanceRoutes, haproxy.InstanceRoute{
+				Name:         svc.Name,
+				Domain:       svc.Domain,
+				BackendIP:    extractHost(svc.Backend.Address),
+				ExtraDomains: svc.ExtraDomains,
+			})
+		case services.BackendHTTP, services.BackendStatic:
+			httpRoutes = append(httpRoutes, haproxy.HTTPRoute{
+				Name:       svc.Name,
+				Domain:     svc.Domain,
+				Backend:    svc.Backend.Address,
+				HealthPath: svc.Backend.Health,
+			})
+		}
+	}
+
+	// Determine central domain for HAProxy
+	centralDomain := ""
+	if globalCfg.Cloud.Central.Domain != "" {
+		centralDomain = globalCfg.Cloud.Central.Domain
+	}
+
+	// Generate and write HAProxy config
+	haproxyCfg := api.haproxy.GenerateWithOpts(instanceRoutes, nil, haproxy.GenerateOpts{
+		CentralDomain: centralDomain,
+		HTTPRoutes:    httpRoutes,
+	})
+
+	if err := api.haproxy.WriteConfig(haproxyCfg); err != nil {
+		slog.Error("reconcile: failed to write HAProxy config", "error", err)
+	} else {
+		if err := api.haproxy.ReloadService(); err != nil {
+			slog.Warn("reconcile: failed to reload HAProxy", "error", err)
+		} else {
+			api.broadcastHaproxyEvent("haproxy:config", "HAProxy config regenerated from registered services")
+		}
+	}
+
+	// Generate dnsmasq DNS entries from registered services
+	// Build instance configs for backward compatibility with dnsmasq generator
+	var instanceConfigs []config.InstanceConfig
+	for _, svc := range svcs {
+		if svc.Reach == services.ReachOff || svc.Domain == "" {
+			continue
+		}
+		ic := config.InstanceConfig{}
+		ic.Cloud.Domain = svc.Domain
+		ic.Cluster.LoadBalancerIp = extractHost(svc.Backend.Address)
+		instanceConfigs = append(instanceConfigs, ic)
+	}
+
+	if err := api.dnsmasq.UpdateConfig(globalCfg, instanceConfigs, true); err != nil {
+		slog.Error("reconcile: failed to update dnsmasq", "error", err)
+	} else {
+		api.broadcastDnsmasqEvent("dnsmasq:config", "DNS config regenerated from registered services")
+	}
+
+	slog.Info("reconcile: networking updated",
+		"services", len(svcs),
+		"l4Routes", len(instanceRoutes),
+		"l7Routes", len(httpRoutes),
+	)
+}
+
+// extractHost gets the host part from a host:port string
+func extractHost(addr string) string {
+	for i := len(addr) - 1; i >= 0; i-- {
+		if addr[i] == ':' {
+			return addr[:i]
+		}
+	}
+	return addr
+}
+
 // broadcastDnsmasqEvent broadcasts SSE events for dnsmasq status changes
 func (api *API) broadcastDnsmasqEvent(eventType string, message string) {
 	if api.sseManager == nil {