feat(aula-14): adicionar Istio Traffic Splitting com canary deployment

- Instala Istio (base + istiod + ingressgateway)
- Configura Kiali e Jaeger para observabilidade
- Deploy de app-backend v1 e v2 com traffic splitting 90/10
- Integra com Victoria Metrics da aula-12
- Inclui teste-stress.sh para validar distribuição de tráfego
- Tráfego externo passa pelo Istio Gateway via NGINX Ingress

aula-14/istio/gateway.yaml

@@ -0,0 +1,36 @@
+apiVersion: networking.istio.io/v1beta1
+kind: Gateway
+metadata:
+  name: app-backend-gateway
+  namespace: istio
+spec:
+  selector:
+    istio: ingressgateway
+  servers:
+    - port:
+        number: 80
+        name: http
+        protocol: HTTP
+      hosts:
+        - "${APP_HOST}"
+---
+apiVersion: networking.istio.io/v1beta1
+kind: VirtualService
+metadata:
+  name: app-backend-external
+  namespace: istio
+spec:
+  hosts:
+    - "${APP_HOST}"
+  gateways:
+    - app-backend-gateway
+  http:
+    - route:
+        - destination:
+            host: app-backend
+            subset: v1
+          weight: 90
+        - destination:
+            host: app-backend
+            subset: v2
+          weight: 10

aula-14/istio/jaeger-values.yaml

@@ -0,0 +1,29 @@
+# Jaeger - Distributed Tracing
+# Tracing para visualizar requisições através do mesh
+
+provisionDataStore:
+  cassandra: false
+
+allInOne:
+  enabled: true
+  image: jaegertracing/all-in-one
+  tag: "1.62"
+  resources:
+    requests:
+      memory: "256Mi"
+      cpu: "100m"
+    limits:
+      memory: "512Mi"
+      cpu: "500m"
+
+storage:
+  type: memory
+
+collector:
+  enabled: false
+
+query:
+  enabled: false
+
+agent:
+  enabled: false

aula-14/istio/kiali-values.yaml

@@ -0,0 +1,24 @@
+# Kiali - Service Mesh Observability
+# Dashboard para visualizar tráfego do Istio
+
+server:
+  web_root: /kiali
+
+auth:
+  strategy: anonymous
+
+deployment:
+  accessible_namespaces:
+    - "**"
+  ingress:
+    enabled: false
+
+external_services:
+  prometheus:
+    url: http://vmsingle-victoria-metrics-k8s-stack.monitoring:8429
+  tracing:
+    enabled: true
+    in_cluster_url: http://tracing.istio-system:16685/jaeger
+    use_grpc: true
+  grafana:
+    enabled: false