feat(home): add support for disabling cluster discovery in Redis configuration

internal/config/home.go

@@ -2,11 +2,12 @@ package config
 
 // HomeConfig configures the optional "home" control plane integration over Redis protocol.
 type HomeConfig struct {
-	Enabled  bool          `yaml:"enabled" json:"enabled"`
-	Host     string        `yaml:"host" json:"-"`
-	Port     int           `yaml:"port" json:"-"`
-	Password string        `yaml:"password" json:"-"`
-	TLS      HomeTLSConfig `yaml:"tls" json:"-"`
+	Enabled                 bool          `yaml:"enabled" json:"enabled"`
+	Host                    string        `yaml:"host" json:"-"`
+	Port                    int           `yaml:"port" json:"-"`
+	Password                string        `yaml:"password" json:"-"`
+	DisableClusterDiscovery bool          `yaml:"disable-cluster-discovery" json:"-"`
+	TLS                     HomeTLSConfig `yaml:"tls" json:"-"`
 }
 
 // HomeTLSConfig configures client-side TLS for the home Redis connection.

internal/config/home_test.go

@@ -9,6 +9,7 @@ home:
   host: home.example.com
   port: 444
   password: secret
+  disable-cluster-discovery: true
   tls:
     enable: true
     server-name: home.example.com
@@ -31,6 +32,9 @@ home:
 	if cfg.Home.Password != "secret" {
 		t.Fatalf("Home.Password = %q, want secret", cfg.Home.Password)
 	}
+	if !cfg.Home.DisableClusterDiscovery {
+		t.Fatal("Home.DisableClusterDiscovery = false, want true")
+	}
 	if !cfg.Home.TLS.Enable {
 		t.Fatal("Home.TLS.Enable = false, want true")
 	}

internal/home/client.go

@@ -265,7 +265,23 @@ func (c *Client) Ping(ctx context.Context) error {
 	return cmd.Ping(ctx).Err()
 }
 
+func (c *Client) clusterDiscoveryEnabled() bool {
+	if c == nil {
+		return false
+	}
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return c.clusterDiscoveryEnabledLocked()
+}
+
+func (c *Client) clusterDiscoveryEnabledLocked() bool {
+	return !c.homeCfg.DisableClusterDiscovery
+}
+
 func (c *Client) refreshBestClusterNode(ctx context.Context) {
+	if !c.clusterDiscoveryEnabled() {
+		return
+	}
 	switched, errRefresh := c.refreshClusterNodes(ctx)
 	if errRefresh != nil {
 		log.Debugf("home cluster nodes unavailable: %v", errRefresh)
@@ -279,6 +295,9 @@ func (c *Client) refreshBestClusterNode(ctx context.Context) {
 }
 
 func (c *Client) refreshClusterNodes(ctx context.Context) (bool, error) {
+	if !c.clusterDiscoveryEnabled() {
+		return false, nil
+	}
 	if ctx == nil {
 		ctx = context.Background()
 	}
@@ -353,6 +372,10 @@ func (c *Client) failoverAfterReconnectFailure() (bool, string) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
+	if !c.clusterDiscoveryEnabledLocked() {
+		c.reconnectFailures = 0
+		return false, ""
+	}
 	c.reconnectFailures++
 	if c.reconnectFailures < homeReconnectFailoverThreshold {
 		return false, ""

internal/home/client_test.go

@@ -1,6 +1,7 @@
 package home
 
 import (
+	"context"
 	"crypto/tls"
 	"encoding/json"
 	"net/http"
@@ -115,3 +116,44 @@ func TestRedisOptionsHomeTLSEnabledUsesExplicitServerName(t *testing.T) {
 		t.Fatal("InsecureSkipVerify = false, want true")
 	}
 }
+
+func TestRefreshClusterNodesDisabledSkipsRedisCommand(t *testing.T) {
+	client := New(config.HomeConfig{
+		Enabled:                 true,
+		Host:                    "127.0.0.1",
+		Port:                    1,
+		DisableClusterDiscovery: true,
+	})
+
+	switched, err := client.refreshClusterNodes(context.Background())
+	if err != nil {
+		t.Fatalf("refreshClusterNodes() error = %v", err)
+	}
+	if switched {
+		t.Fatal("refreshClusterNodes() switched = true, want false")
+	}
+	if client.cmd != nil || client.sub != nil {
+		t.Fatalf("redis clients were initialized when cluster discovery was disabled")
+	}
+}
+
+func TestFailoverAfterReconnectFailureDisabledDoesNotSwitchToClusterNode(t *testing.T) {
+	client := New(config.HomeConfig{
+		Enabled:                 true,
+		Host:                    "seed.example.com",
+		Port:                    8327,
+		DisableClusterDiscovery: true,
+	})
+	client.mu.Lock()
+	client.clusterNodes = []clusterNode{{IP: "other.example.com", Port: 8327}}
+	client.reconnectFailures = homeReconnectFailoverThreshold - 1
+	client.mu.Unlock()
+
+	switched, addr := client.failoverAfterReconnectFailure()
+	if switched {
+		t.Fatalf("failoverAfterReconnectFailure() switched to %s, want no switch", addr)
+	}
+	if got, _ := client.addr(); got != "seed.example.com:8327" {
+		t.Fatalf("addr() = %q, want seed.example.com:8327", got)
+	}
+}