Egress 网关的 TLS 发起过程

为 Egress 流量发起 TLS 连接 示例中演示了如何配置 Istio 以对外部服务流量实施 TLS origination配置 Egress Gateway 示例中演示了如何配置 Istio 来通过专门的 egress 网关服务引导 egress 流量。 本示例兼容以上两者,描述如何配置 egress 网关,为外部服务流量发起 TLS 连接。

开始之前

  • 遵照安装指南中的指令,安装 Istio。

  • 启动 sleep 样本应用,作为外部请求的测试源。

    若已开启自动 sidecar 注入,执行

    Zip
    $ kubectl apply -f @samples/sleep/sleep.yaml@
    

    否则,必须在部署 sleep 应用之前手动注入 sidecar:

    Zip
    $ kubectl apply -f <(istioctl kube-inject -f @samples/sleep/sleep.yaml@)
    

    注意每一个可以执行 execcurl 操作的 pod,都需要注入。

  • 创建一个 shell 变量,来保存向外部服务发送请求的源 pod 的名称。 若使用 sleep 样例,运行:

    $ export SOURCE_POD=$(kubectl get pod -l app=sleep -o jsonpath={.items..metadata.name})
    
  • 对于 macOS 用户,确认您使用的是 openssl 版本 1.1 或更高版本:

    $ openssl version -a | grep OpenSSL
    OpenSSL 1.1.1g  21 Apr 2020
    

    如果前面的命令输出的是版本 1.1 或更高版本,如图所示,则您的 openssl 命令应该正确执行此任务中的指示。否则,升级您的 openssl 或尝试 openssl 的不同实现,像在 Linux 机器上一样。

  • 部署 Istio egress 网关

  • 开启 Envoy 的访问日志

通过 egress 网关发起 TLS 连接

本节描述如何使用 egress 网关发起与示例为 Egress 流量发起 TLS 连接中一样的 TLS。 注意,这种情况下,TLS 的发起过程由 egress 网关完成,而不是像之前示例演示的那样由 sidecar 完成。

  1. edition.cnn.com 定义一个 ServiceEntry

    $ kubectl apply -f - <<EOF
    apiVersion: networking.istio.io/v1alpha3
    kind: ServiceEntry
    metadata:
      name: cnn
    spec:
      hosts:
      - edition.cnn.com
      ports:
      - number: 80
        name: http
        protocol: HTTP
      - number: 443
        name: https
        protocol: HTTPS
      resolution: DNS
    EOF
    
  2. 发送一个请求至 http://edition.cnn.com/politics,验证 ServiceEntry 已被正确应用。

    $ kubectl exec -it $SOURCE_POD -c sleep -- curl -sL -o /dev/null -D - http://edition.cnn.com/politics
    HTTP/1.1 301 Moved Permanently
    ...
    location: https://edition.cnn.com/politics
    ...
    
    command terminated with exit code 35
    

    如果在输出中看到 _301 Moved Permanently_,说明 ServiceEntry 配置正确。

  3. edition.cnn.com 创建一个 egress Gateway,端口 443,以及一个 sidecar 请求的目标规则,sidecar 请求被直接导向 egress 网关。

    $ kubectl apply -f - <<EOF
    apiVersion: networking.istio.io/v1alpha3
    kind: Gateway
    metadata:
      name: istio-egressgateway
    spec:
      selector:
        istio: egressgateway
      servers:
      - port:
          number: 80
          name: https-port-for-tls-origination
          protocol: HTTPS
        hosts:
        - edition.cnn.com
        tls:
          mode: ISTIO_MUTUAL
    ---
    apiVersion: networking.istio.io/v1alpha3
    kind: DestinationRule
    metadata:
      name: egressgateway-for-cnn
    spec:
      host: istio-egressgateway.istio-system.svc.cluster.local
      subsets:
      - name: cnn
        trafficPolicy:
          loadBalancer:
            simple: ROUND_ROBIN
          portLevelSettings:
          - port:
              number: 80
            tls:
              mode: ISTIO_MUTUAL
              sni: edition.cnn.com
    EOF
    
  4. 定义一个 VirtualService 来引导流量流经 egress 网关,以及一个 DestinationRule 为访问 edition.cnn.com 的请求发起 TLS 连接:

    $ kubectl apply -f - <<EOF
    apiVersion: networking.istio.io/v1alpha3
    kind: VirtualService
    metadata:
      name: direct-cnn-through-egress-gateway
    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: 443
          weight: 100
    ---
    apiVersion: networking.istio.io/v1alpha3
    kind: DestinationRule
    metadata:
      name: originate-tls-for-edition-cnn-com
    spec:
      host: edition.cnn.com
      trafficPolicy:
        loadBalancer:
          simple: ROUND_ROBIN
        portLevelSettings:
        - port:
            number: 443
          tls:
            mode: SIMPLE # initiates HTTPS for connections to edition.cnn.com
    EOF
    
  5. 发送一个 HTTP 请求至 http://edition.cnn.com/politics

    $ kubectl exec -it $SOURCE_POD -c sleep -- curl -sL -o /dev/null -D - http://edition.cnn.com/politics
    HTTP/1.1 200 OK
    ...
    

    输出将与在示例为 Egress 流量发起 TLS 连接中显示的一样,发起 TLS 连接后,不再显示 301 Moved Permanently 消息。

  6. 检查 istio-egressgateway pod 的日志,将看到一行与请求相关的记录。 若 Istio 部署在 istio-system 命名空间中,打印日志的命令为:

    $ kubectl logs -l istio=egressgateway -c istio-proxy -n istio-system | tail
    

    将看到类似如下一行:

    [2020-06-30T16:17:56.763Z] "GET /politics HTTP/2" 200 - "-" "-" 0 1295938 529 89 "10.244.0.171" "curl/7.64.0" "cf76518d-3209-9ab7-a1d0-e6002728ef5b" "edition.cnn.com" "151.101.129.67:443" outbound|443||edition.cnn.com 10.244.0.170:54280 10.244.0.170:8080 10.244.0.171:35628 - -
    

清除 TLS 启动实例

删除创建的 Istio 配置项:

$ kubectl delete gateway istio-egressgateway
$ kubectl delete serviceentry cnn
$ kubectl delete virtualservice direct-cnn-through-egress-gateway
$ kubectl delete destinationrule originate-tls-for-edition-cnn-com
$ kubectl delete destinationrule egressgateway-for-cnn

通过 egress 网关发起双向 TLS 连接

与前一章节类似,本章节描述如何配置一个 egress 网关,为外部服务发起 TLS 连接,只是这次服务要求双向 TLS。

本示例要求更高的参与性,首先需要:

  1. 生成客户端和服务器证书
  2. 部署一个支持双向 TLS 的外部服务
  3. 使用所需的证书重新部署 egress 网关

然后才可以配置出口流量流经 egress 网关,egress 网关将发起 TLS 连接。

生成客户端和服务器的证书与密钥

对于此任务,您可以使用自己喜欢的工具来生成证书和密钥。以下命令使用openssl

  1. 为您的服务签名证书创建根证书和私钥:

    $ openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -subj '/O=example Inc./CN=example.com' -keyout example.com.key -out example.com.crt
    
  2. my-nginx.mesh-external.svc.cluster.local 创建证书和私钥:

    $ openssl req -out my-nginx.mesh-external.svc.cluster.local.csr -newkey rsa:2048 -nodes -keyout my-nginx.mesh-external.svc.cluster.local.key -subj "/CN=my-nginx.mesh-external.svc.cluster.local/O=some organization"
    $ openssl x509 -req -sha256 -days 365 -CA example.com.crt -CAkey example.com.key -set_serial 0 -in my-nginx.mesh-external.svc.cluster.local.csr -out my-nginx.mesh-external.svc.cluster.local.crt
    
  3. 生成客户端证书和私钥:

    $ openssl req -out client.example.com.csr -newkey rsa:2048 -nodes -keyout client.example.com.key -subj "/CN=client.example.com/O=client organization"
    $ openssl x509 -req -sha256 -days 365 -CA example.com.crt -CAkey example.com.key -set_serial 1 -in client.example.com.csr -out client.example.com.crt
    

部署一个双向 TLS 服务器

为了模拟一个真实的支持双向 TLS 协议的外部服务, 在 Kubernetes 集群中部署一个 NGINX 服务器,该服务器运行在 Istio 服务网格之外,譬如:运行在一个没有开启 Istio sidecar proxy 注入的命名空间中。

  1. 创建一个命名空间,表示 Istio 网格之外的服务,mesh-external。注意在这个命名空间中,sidecar 自动注入是没有开启的,不会在 pods 中自动注入 sidecar proxy。

    $ kubectl create namespace mesh-external
    
  2. 创建 Kubernetes Secrets ,保存服务器和 CA 的证书。

    $ kubectl create -n mesh-external secret tls nginx-server-certs --key my-nginx.mesh-external.svc.cluster.local.key --cert my-nginx.mesh-external.svc.cluster.local.crt
    $ kubectl create -n mesh-external secret generic nginx-ca-certs --from-file=example.com.crt
    
  3. 生成 NGINX 服务器的配置文件:

    $ cat <<\EOF > ./nginx.conf
    events {
    }
    
    http {
      log_format main '$remote_addr - $remote_user [$time_local]  $status '
      '"$request" $body_bytes_sent "$http_referer" '
      '"$http_user_agent" "$http_x_forwarded_for"';
      access_log /var/log/nginx/access.log main;
      error_log  /var/log/nginx/error.log;
    
      server {
        listen 443 ssl;
    
        root /usr/share/nginx/html;
        index index.html;
    
        server_name my-nginx.mesh-external.svc.cluster.local;
        ssl_certificate /etc/nginx-server-certs/tls.crt;
        ssl_certificate_key /etc/nginx-server-certs/tls.key;
        ssl_client_certificate /etc/nginx-ca-certs/example.com.crt;
        ssl_verify_client on;
      }
    }
    EOF
    
  4. 生成 Kubernetes ConfigMap 保存 NGINX 服务器的配置文件:

    $ kubectl create configmap nginx-configmap -n mesh-external --from-file=nginx.conf=./nginx.conf
    
  5. 部署 NGINX 服务器:

    $ kubectl apply -f - <<EOF
    apiVersion: v1
    kind: Service
    metadata:
      name: my-nginx
      namespace: mesh-external
      labels:
        run: my-nginx
    spec:
      ports:
      - port: 443
        protocol: TCP
      selector:
        run: my-nginx
    ---
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: my-nginx
      namespace: mesh-external
    spec:
      selector:
        matchLabels:
          run: my-nginx
      replicas: 1
      template:
        metadata:
          labels:
            run: my-nginx
        spec:
          containers:
          - name: my-nginx
            image: nginx
            ports:
            - containerPort: 443
            volumeMounts:
            - name: nginx-config
              mountPath: /etc/nginx
              readOnly: true
            - name: nginx-server-certs
              mountPath: /etc/nginx-server-certs
              readOnly: true
            - name: nginx-ca-certs
              mountPath: /etc/nginx-ca-certs
              readOnly: true
          volumes:
          - name: nginx-config
            configMap:
              name: nginx-configmap
          - name: nginx-server-certs
            secret:
              secretName: nginx-server-certs
          - name: nginx-ca-certs
            secret:
              secretName: nginx-ca-certs
    EOF
    
  6. nginx.example.com 定义一个 ServiceEntry 和一个 VirtualService,指示 Istio 引导目标为 nginx.example.com 的流量流向 NGINX 服务器:

    $ kubectl apply -f - <<EOF
    apiVersion: networking.istio.io/v1alpha3
    kind: ServiceEntry
    metadata:
      name: nginx
    spec:
      hosts:
      - nginx.example.com
      ports:
      - number: 80
        name: http
        protocol: HTTP
      - number: 443
        name: https
        protocol: HTTPS
      resolution: DNS
      endpoints:
      - address: my-nginx.mesh-external.svc.cluster.local
        ports:
          https: 443
    ---
    apiVersion: networking.istio.io/v1alpha3
    kind: VirtualService
    metadata:
      name: nginx
    spec:
      hosts:
      - nginx.example.com
      tls:
      - match:
        - port: 443
          sni_hosts:
          - nginx.example.com
        route:
        - destination:
            host: nginx.example.com
            port:
              number: 443
          weight: 100
    EOF
    

使用客户端证书重新部署 egress 网关

  1. 生成 Kubernetes Secrets 保存客户端和 CA 的证书。

    $ kubectl create -n istio-system secret tls nginx-client-certs --key client.example.com.key --cert client.example.com.crt
    $ kubectl create -n istio-system secret generic nginx-ca-certs --from-file=example.com.crt
    
  2. 部署 istio-egressgateway 挂载新生成的 Secrets 的 Volume。使用的参数选项与生成 istio.yaml 中的一致,创建下面的 gateway-patch.json 文件:

    $ cat > gateway-patch.json <<EOF
    [{
      "op": "add",
      "path": "/spec/template/spec/containers/0/volumeMounts/0",
      "value": {
        "mountPath": "/etc/istio/nginx-client-certs",
        "name": "nginx-client-certs",
        "readOnly": true
      }
    },
    {
      "op": "add",
      "path": "/spec/template/spec/volumes/0",
      "value": {
      "name": "nginx-client-certs",
        "secret": {
          "secretName": "nginx-client-certs",
          "optional": true
        }
      }
    },
    {
      "op": "add",
      "path": "/spec/template/spec/containers/0/volumeMounts/1",
      "value": {
        "mountPath": "/etc/istio/nginx-ca-certs",
        "name": "nginx-ca-certs",
        "readOnly": true
      }
    },
    {
      "op": "add",
      "path": "/spec/template/spec/volumes/1",
      "value": {
      "name": "nginx-ca-certs",
        "secret": {
          "secretName": "nginx-ca-certs",
          "optional": true
        }
      }
    }]
    EOF
    
  3. 通过以下命令部署应用 istio-egressgateway

    $ kubectl -n istio-system patch --type=json deploy istio-egressgateway -p "$(cat gateway-patch.json)"
    
  4. 验证密钥和证书被成功装载入 istio-egressgateway pod:

    $ kubectl exec -n istio-system "$(kubectl -n istio-system get pods -l istio=egressgateway -o jsonpath='{.items[0].metadata.name}')" -- ls -al /etc/istio/nginx-client-certs /etc/istio/nginx-ca-certs
    

    tls.crttls.key/etc/istio/nginx-client-certs 中,而 ca-chain.cert.pem/etc/istio/nginx-ca-certs 中。

为 egress 流量配置双向 TLS

  1. my-nginx.mesh-external.svc.cluster.local 创建一个 egress Gateway 端口为 443,以及目标规则和虚拟服务来引导流量流经 egress 网关并从 egress 网关流向外部服务。

    $ kubectl apply -f - <<EOF
    apiVersion: networking.istio.io/v1alpha3
    kind: Gateway
    metadata:
      name: istio-egressgateway
    spec:
      selector:
        istio: egressgateway
      servers:
      - port:
          number: 443
          name: https
          protocol: HTTPS
        hosts:
        - my-nginx.mesh-external.svc.cluster.local
        tls:
          mode: ISTIO_MUTUAL
    ---
    apiVersion: networking.istio.io/v1alpha3
    kind: DestinationRule
    metadata:
      name: egressgateway-for-nginx
    spec:
      host: istio-egressgateway.istio-system.svc.cluster.local
      subsets:
      - name: nginx
        trafficPolicy:
          loadBalancer:
            simple: ROUND_ROBIN
          portLevelSettings:
          - port:
              number: 443
            tls:
              mode: ISTIO_MUTUAL
              sni: my-nginx.mesh-external.svc.cluster.local
    EOF
    
  2. 定义一个 VirtualService 引导流量流经 egress 网关:

    $ kubectl apply -f - <<EOF
    apiVersion: networking.istio.io/v1alpha3
    kind: VirtualService
    metadata:
      name: direct-nginx-through-egress-gateway
    spec:
      hosts:
      - my-nginx.mesh-external.svc.cluster.local
      gateways:
      - istio-egressgateway
      - mesh
      http:
      - match:
        - gateways:
          - mesh
          port: 80
        route:
        - destination:
            host: istio-egressgateway.istio-system.svc.cluster.local
            subset: nginx
            port:
              number: 443
          weight: 100
      - match:
        - gateways:
          - istio-egressgateway
          port: 443
        route:
        - destination:
            host: my-nginx.mesh-external.svc.cluster.local
            port:
              number: 443
          weight: 100
    EOF
    
  3. 添加 DestinationRule 执行双向 TLS

    $ kubectl apply -n istio-system -f - <<EOF
    apiVersion: networking.istio.io/v1alpha3
    kind: DestinationRule
    metadata:
      name: originate-mtls-for-nginx
    spec:
      host: my-nginx.mesh-external.svc.cluster.local
      trafficPolicy:
        loadBalancer:
          simple: ROUND_ROBIN
        portLevelSettings:
        - port:
            number: 443
          tls:
            mode: MUTUAL
            clientCertificate: /etc/istio/nginx-client-certs/tls.crt
            privateKey: /etc/istio/nginx-client-certs/tls.key
            caCertificates: /etc/istio/nginx-ca-certs/example.com.crt
            sni: my-nginx.mesh-external.svc.cluster.local
    EOF
    
  4. 发送一个 HTTP 请求至 http://my-nginx.mesh-external.svc.cluster.local

    $ kubectl exec "$(kubectl get pod -l app=sleep -o jsonpath={.items..metadata.name})" -c sleep -- curl -sS http://my-nginx.mesh-external.svc.cluster.local
    <!DOCTYPE html>
    <html>
    <head>
    <title>Welcome to nginx!</title>
    ...
    
  5. 检查 istio-egressgateway pod 日志,有一行与请求相关的日志记录。 如果 Istio 部署在命名空间 istio-system 中,打印日志的命令为:

    $ kubectl logs -l istio=egressgateway -n istio-system | grep 'my-nginx.mesh-external.svc.cluster.local' | grep HTTP
    

    将显示类似如下的一行:

    [2018-08-19T18:20:40.096Z] "GET / HTTP/1.1" 200 - 0 612 7 5 "172.30.146.114" "curl/7.35.0" "b942b587-fac2-9756-8ec6-303561356204" "my-nginx.mesh-external.svc.cluster.local" "172.21.72.197:443"
    

清除双向 TLS 连接示例

  1. 删除创建的 Kubernetes 资源:

    $ kubectl delete secret nginx-server-certs nginx-ca-certs -n mesh-external
    $ kubectl delete secret istio-egressgateway-certs istio-egressgateway-ca-certs nginx-client-certs nginx-ca-certs -n istio-system
    $ kubectl delete configmap nginx-configmap -n mesh-external
    $ kubectl delete service my-nginx -n mesh-external
    $ kubectl delete deployment my-nginx -n mesh-external
    $ kubectl delete namespace mesh-external
    $ kubectl delete gateway istio-egressgateway
    $ kubectl delete virtualservice direct-nginx-through-egress-gateway
    $ kubectl delete destinationrule -n istio-system originate-mtls-for-nginx
    $ kubectl delete destinationrule egressgateway-for-nginx
    
  2. 删除证书和私钥:

    $ rm example.com.crt example.com.key my-nginx.mesh-external.svc.cluster.local.crt my-nginx.mesh-external.svc.cluster.local.key my-nginx.mesh-external.svc.cluster.local.csr client.example.com.crt client.example.com.csr client.example.com.key
    
  3. 删除生成并应用于示例中的配置文件

    $ rm ./nginx.conf
    $ rm ./gateway-patch.json
    

清除

删除 sleep 服务和部署:

$ kubectl delete service sleep
$ kubectl delete deployment sleep
这些信息有用吗?
Do you have any suggestions for improvement?

Thanks for your feedback!