fix(agents-login): strip AAAA via CoreDNS sidecar so codex sign-in uses IPv4

platform/cluster/flux/apps/agents/agents-login/worker.yaml

@@ -1,3 +1,28 @@
+# Pod-local resolver for the agents-login worker. Codex 0.141.x ships a musl
+# static binary whose resolver ignores /etc/gai.conf and /etc/hosts for the
+# failing auth.openai.com path; this CoreDNS sidecar strips AAAA at DNS level
+# while forwarding every non-AAAA lookup to kube-dns.
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: agents-login-worker-coredns
+  namespace: agents-system
+  labels:
+    app.kubernetes.io/name: agents-login-worker
+    app.kubernetes.io/part-of: agents-login
+data:
+  Corefile: |
+    .:53 {
+        errors
+        health :8080
+        ready :8181
+        template IN AAAA . {
+            rcode NOERROR
+        }
+        forward . 10.43.0.10
+        cache 30
+    }
+---
 # Private half of the portal. Owns the PTY that runs `claude setup-token` and
 # `codex login --device`, captures credentials, and posts them to agents-api
 # under a Lease lock. Single instance + Recreate so the Lease is never
@@ -33,6 +58,17 @@ spec:
     spec:
       serviceAccountName: agents-login-worker
       automountServiceAccountToken: true
+      dnsPolicy: None
+      dnsConfig:
+        nameservers:
+          - 127.0.0.1
+        searches:
+          - agents-system.svc.cluster.local
+          - svc.cluster.local
+          - cluster.local
+        options:
+          - name: ndots
+            value: '5'
       # The image is amd64-only (it bundles the Claude/Codex CLIs + node-pty and
       # is not worth a QEMU arm64 build). Keep it off the arm64 Pi nodes, where
       # it would ImagePullBackOff on "no match for platform in manifest".
@@ -45,74 +81,50 @@ spec:
         fsGroup: 1000
         seccompProfile:
           type: RuntimeDefault
-      # Codex 0.141.x ships a musl static binary. In this cluster IPv6 egress is
-      # unreachable, and musl ignores /etc/gai.conf, so auth.openai.com AAAA
-      # answers can make `codex login --device-auth` fail before it tries IPv4.
-      # Resolve A records at pod startup and mount a pod-local hosts file instead
-      # of using static hostAliases, which would stale when Cloudflare rotates IPs.
-      initContainers:
-        - name: codex-auth-hosts
-          image: ghcr.io/extratoast/personal-stack/agents-login:latest
-          imagePullPolicy: Always
-          command:
-            - node
-            - -e
-            - |
-              const dns = require('node:dns').promises;
-              const { writeFileSync } = require('node:fs');
-
-              const hosts = (process.env.CODEX_IPV4_HOSTS || 'auth.openai.com')
-                .split(/[\s,]+/)
-                .filter(Boolean);
-              const podIp = process.env.POD_IP || '127.0.0.1';
-              const hostname = process.env.HOSTNAME || 'agents-login-worker';
-              const lines = [
-                '# Kubernetes hosts file generated by codex-auth-hosts.',
-                '127.0.0.1\tlocalhost',
-                '::1\tlocalhost ip6-localhost ip6-loopback',
-                'fe00::0\tip6-localnet',
-                'fe00::0\tip6-mcastprefix',
-                'fe00::1\tip6-allnodes',
-                'fe00::2\tip6-allrouters',
-                `${podIp}\t${hostname}`,
-                '',
-              ];
-
-              (async () => {
-                for (const host of hosts) {
-                  const ips = await dns.resolve4(host);
-                  if (ips.length === 0) {
-                    throw new Error(`no A records for ${host}`);
-                  }
-                  for (const ip of ips) {
-                    lines.push(`${ip}\t${host}`);
-                  }
-                  console.log(`resolved ${host}: ${ips.join(', ')}`);
-                }
-                writeFileSync('/generated-hosts/hosts', `${lines.join('\n')}\n`, { mode: 0o644 });
-              })().catch((err) => {
-                console.error(err);
-                process.exit(1);
-              });
-          env:
-            - name: CODEX_IPV4_HOSTS
-              value: auth.openai.com
-            - name: POD_IP
-              valueFrom:
-                fieldRef:
-                  fieldPath: status.podIP
+      containers:
+        - name: dns
+          image: registry.k8s.io/coredns/coredns:v1.12.1
+          imagePullPolicy: IfNotPresent
+          args:
+            - -conf
+            - /etc/coredns/Corefile
+          ports:
+            - name: dns-udp
+              containerPort: 53
+              protocol: UDP
+            - name: dns-tcp
+              containerPort: 53
+              protocol: TCP
           securityContext:
-            runAsNonRoot: false
-            runAsUser: 0
-            runAsGroup: 0
             allowPrivilegeEscalation: false
             readOnlyRootFilesystem: true
+            runAsNonRoot: true
             capabilities:
               drop: ['ALL']
+              add: ['NET_BIND_SERVICE']
           volumeMounts:
-            - name: codex-auth-hosts
-              mountPath: /generated-hosts
-      containers:
+            - name: coredns-config
+              mountPath: /etc/coredns
+              readOnly: true
+          readinessProbe:
+            httpGet:
+              path: /ready
+              port: 8181
+            initialDelaySeconds: 1
+            periodSeconds: 10
+          livenessProbe:
+            httpGet:
+              path: /health
+              port: 8080
+            initialDelaySeconds: 5
+            periodSeconds: 20
+          resources:
+            requests:
+              cpu: 5m
+              memory: 16Mi
+            limits:
+              cpu: 100m
+              memory: 64Mi
         - name: worker
           image: ghcr.io/extratoast/personal-stack/agents-login:latest
           imagePullPolicy: Always
@@ -151,10 +163,6 @@ spec:
             capabilities:
               drop: ['ALL']
           volumeMounts:
-            - name: codex-auth-hosts
-              mountPath: /etc/hosts
-              subPath: hosts
-              readOnly: true
             - name: home
               mountPath: /home/agent
             - name: tmp
@@ -177,8 +185,9 @@ spec:
               cpu: 500m
               memory: 512Mi
       volumes:
-        - name: codex-auth-hosts
-          emptyDir: {}
+        - name: coredns-config
+          configMap:
+            name: agents-login-worker-coredns
         - name: home
           emptyDir: {}
         - name: tmp