我已经使用以下配置安装了 ISTIO
cat << EOF | kubectl apply -f -
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
metadata:
namespace: istio-system
name: istio-control-plane
spec:
# Use the default profile as the base
# More details at: https://istio.io/docs/setup/additional-setup/config-profiles/
profile: default
# Enable the addons that we will want to use
addonComponents:
grafana:
enabled: true
prometheus:
enabled: true
tracing:
enabled: true
kiali:
enabled: true
values:
global:
# Ensure that the Istio pods are only scheduled to run on Linux nodes
defaultNodeSelector:
beta.kubernetes.io/os: linux
kiali:
dashboard:
auth:
strategy: anonymous
components:
egressGateways:
- name: istio-egressgateway
enabled: true
meshConfig:
accessLogFile: /dev/stdout
outboundTrafficPolicy:
mode: REGISTRY_ONLY
EOF
并已配置 Egress Gateway、Destination Rule 和 Virtual Service，如下所示
cat << EOF | kubectl apply -f -
apiVersion: v1
kind: Namespace
metadata:
name: akv2k8s-test
labels:
istio-injection: enabled
azure-key-vault-env-injection: enabled
---
apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
name: cnn
namespace: akv2k8s-test
spec:
hosts:
- edition.cnn.com
ports:
- number: 80
name: http-port
protocol: HTTP
- number: 443
name: https
protocol: HTTPS
resolution: DNS
---
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
name: istio-egressgateway
namespace: akv2k8s-test
spec:
selector:
istio: egressgateway
servers:
- port:
number: 80
name: http
protocol: HTTP
hosts:
- edition.cnn.com
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: egressgateway-for-cnn
namespace: akv2k8s-test
spec:
host: istio-egressgateway.istio-system.svc.cluster.local
subsets:
- name: cnn
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: direct-cnn-through-egress-gateway
namespace: akv2k8s-test
spec:
hosts:
- edition.cnn.com
gateways:
- istio-egressgateway
- mesh
http:
- match:
- gateways:
- mesh
port: 80
route:
- destination:
host: istio-egressgateway.istio-system.svc.cluster.local
subset: cnn
port:
number: 80
weight: 100
- match:
- gateways:
- istio-egressgateway
port: 80
route:
- destination:
host: edition.cnn.com
port:
number: 80
weight: 100
EOF
它工作得很好
kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.7/samples/sleep/sleep.yaml -n akv2k8s-test
export SOURCE_POD=$(kubectl get pod -l app=sleep -n akv2k8s-test -o jsonpath={.items..metadata.name})
kubectl exec "$SOURCE_POD" -n akv2k8s-test -c sleep -- curl -sL -o /dev/null -D - http://edition.cnn.com/politics
kubectl logs -l istio=egressgateway -c istio-proxy -n istio-system | tail
但是我无法理解控制流程。例如，下图显示了 Ingress Gateway 的控制流程
你能告诉我ISTIO Egress的控制流程吗？或者当部署的应用程序尝试访问外部服务时会发生什么？是否遵循以下流程：POD -> 代理 -> 虚拟服务 -> 目标规则 -> 网关 -> 外部服务？