fix: wrong k8s lookup mode

deployments/k8s-sidecar/base/configmap.yaml

@@ -109,16 +109,15 @@ data:
     }
 
     membership {
-        service-name "drl"
+        service-name "drl-headless.drl.svc.cluster.local"
         port 7946
         bind-addr "0.0.0.0"
-        join-addr "drl-headless.drl.svc.cluster.local"
         startup-delay "3s"
     }
 
     logging {
-        level "info"
-        format "json"
+        level "debug"
+        format "text"
     }
 
     internal-api {

deployments/k8s-sidecar/base/deployment.yaml

@@ -15,13 +15,6 @@ spec:
       labels:
         app: echo-server
     spec:
-      # Ensure DRL sidecar is ready before Envoy (init container approach avoids
-      # Kubernetes sidecar ordering limitations on older clusters).
-      initContainers:
-        - name: wait-for-drl
-          image: busybox:1.36
-          command: ["sh", "-c", "until wget -q --spider http://127.0.0.1:9091/health; do echo 'waiting for DRL...'; sleep 2; done"]
-
       containers:
         # ── echo-server ────────────────────────────────────────────────────────
         - name: echo-server
@@ -63,8 +56,8 @@ spec:
 
         # ── drl sidecar ────────────────────────────────────────────────────────
         - name: drl
-          image: ghcr.io/your-org/drl:latest  # replace with your image
-          args: ["serve"]
+          image: ghcr.io/gchiesa/drl:latest
+          args: []
           env:
             - name: DRL_CONFIG_PATH
               value: /etc/drl/config.kdl

deployments/k8s-sidecar/base/kustomization.yaml

@@ -4,14 +4,13 @@ kind: Kustomization
 namespace: drl
 
 resources:
-  - namespace.yaml
   - configmap.yaml
   - deployment.yaml
   - service.yaml
 
 # Replace with your actual DRL image
 images:
-  - name: ghcr.io/your-org/drl
+  - name: ghcr.io/gchiesa/drl
     newTag: latest
 
 # Generate the DRL secrets from a local .env file (for local dev only).

internal/membership/membership.go

@@ -1,6 +1,7 @@
 package membership
 
 import (
+	"context"
 	"fmt"
 	"log/slog"
 	"net"
@@ -212,19 +213,61 @@ func (c *Cluster) markReady() {
 	}
 }
 
-// discoverPeers resolves the discovery service name to get peer IPs
+// privateIPv4Nets are the RFC 1918 ranges plus link-local. Pod IPs in any
+// Kubernetes CNI will always fall inside one of these; public addresses
+// (e.g. AWS Global Accelerator) never will.
+var privateIPv4Nets = func() []*net.IPNet {
+	var nets []*net.IPNet
+	for _, cidr := range []string{
+		"10.0.0.0/8",
+		"172.16.0.0/12",
+		"192.168.0.0/16",
+		"169.254.0.0/16",
+	} {
+		_, n, _ := net.ParseCIDR(cidr)
+		nets = append(nets, n)
+	}
+	return nets
+}()
+
+// discoverPeers resolves the discovery service name to get peer IPs.
+//
+// net.LookupIP is intentionally avoided: with CGO_ENABLED=0 the pure-Go
+// resolver does not always apply /etc/resolv.conf search domains and ndots
+// in the same order as the system libc resolver, which can cause the name to
+// be resolved by an upstream public DNS server instead of the cluster DNS,
+// returning unexpected public IPs.
+//
+// Using net.DefaultResolver.LookupIPAddr with a context ensures the pure-Go
+// resolver path is taken with full resolv.conf semantics. Results are also
+// filtered to RFC 1918 private ranges so a misconfigured DNS can never inject
+// a public address into the peer list.
 func (c *Cluster) discoverPeers() ([]string, error) {
-	ips, err := net.LookupIP(c.config.Membership.ServiceName)
+	addrs, err := net.DefaultResolver.LookupIPAddr(context.Background(), c.config.Membership.ServiceName)
 	if err != nil {
 		return nil, fmt.Errorf("DNS lookup failed: %w", err)
 	}
 
 	var peers []string
-	for _, ip := range ips {
-		// Only use IPv4 addresses
-		if ip.To4() != nil {
-			peers = append(peers, ip.String())
+	for _, addr := range addrs {
+		ip := addr.IP.To4()
+		if ip == nil {
+			continue // skip IPv6
+		}
+		private := false
+		for _, n := range privateIPv4Nets {
+			if n.Contains(ip) {
+				private = true
+				break
+			}
+		}
+		if !private {
+			c.logger.Warn("discoverPeers: ignoring non-private IP returned by DNS",
+				slog.String("service", c.config.Membership.ServiceName),
+				slog.String("ip", ip.String()))
+			continue
 		}
+		peers = append(peers, ip.String())
 	}
 
 	return peers, nil