fix(client): allow training pods to reach mysql-client (v1.2.1)

client/Chart.yaml

@@ -2,8 +2,8 @@ apiVersion: v2
 name: client
 description: A unified Helm chart for tracebloc on AKS, EKS, bare-metal, and OpenShift
 type: application
-version: 1.2.0
-appVersion: "1.2.0"
+version: 1.2.1
+appVersion: "1.2.1"
 keywords:
   - tracebloc
   - kubernetes

client/templates/network-policy-training.yaml

@@ -6,7 +6,14 @@
     1. Denies all ingress to training pods (nothing should connect TO them).
     2. Allows DNS to the cluster's DNS service.
     3. Allows TCP/443 egress to addresses OUTSIDE the cluster CIDRs only —
-       blocking pod-to-pod, MySQL, K8s API, jobs-manager pod IPs, etc.
+       blocking pod-to-pod, K8s API, jobs-manager pod IPs, etc.
+    4. Allows TCP/3306 egress to the in-namespace mysql-client pod.
+       Training pods load their training dataset via
+       core/utils/database.py::load_dataframe_from_sql_table; without this
+       rule the connect fails with "Can't connect to MySQL server (111)"
+       and the job CrashLoopBackOffs before the first batch.
+       Scoped by podSelector (app=mysql-client) so it stays tight to the
+       chart's own mysql pod and does not open the namespace generally.
 
   Selects pods by label tracebloc.io/workload=training. The jobs-manager
   injects this label when spawning each training Job (see client-runtime
@@ -56,7 +63,8 @@ spec:
           protocol: TCP
     # 2. External HTTPS — everything NOT in the cluster's pod/service CIDRs.
     #    Training pods call backend, Azure Service Bus, App Insights, etc.
-    #    This blocks pod-to-pod, ClusterIPs, MySQL, jobs-manager, K8s API.
+    #    This blocks pod-to-pod, ClusterIPs, jobs-manager, K8s API. MySQL is
+    #    explicitly re-permitted by the next rule.
     - to:
         - ipBlock:
             cidr: 0.0.0.0/0
@@ -67,4 +75,14 @@ spec:
       ports:
         - port: 443
           protocol: TCP
+    # 3. MySQL — training pods read the training dataset from the
+    #    in-namespace mysql-client pod. podSelector with no namespaceSelector
+    #    matches pods in the same namespace as this NetworkPolicy.
+    - to:
+        - podSelector:
+            matchLabels:
+              app: mysql-client
+      ports:
+        - port: 3306
+          protocol: TCP
 {{- end }}

client/tests/network_policy_test.yaml

@@ -171,6 +171,29 @@ tests:
             port: 443
             protocol: TCP
 
+  - it: should allow TCP 3306 egress to the in-namespace mysql-client pod
+    set:
+      networkPolicy:
+        training:
+          enabled: true
+          dnsNamespace: kube-system
+          dnsSelector:
+            k8s-app: kube-dns
+          clusterCidrs:
+            - 10.0.0.0/8
+    asserts:
+      - equal:
+          path: spec.egress[2].to[0]
+          value:
+            podSelector:
+              matchLabels:
+                app: mysql-client
+      - contains:
+          path: spec.egress[2].ports
+          content:
+            port: 3306
+            protocol: TCP
+
   - it: should support OpenShift DNS selector override
     set:
       networkPolicy: