Egress TLS 流量中的 SNI 监控及策略

在使用通配符主机配置 Egress 流量示例中描述了为 *.wikipedia.org 这样的域名启用 Egress 流量 TLS 支持的方法。本示例中将演示的是如何为 Egress TLS 流量配置 SNI 监控并应用策略。

开始之前

  • 按照安装指南中的说明安装 Istio。

  • 启动 sleep 示例，以获取发送请求的测试源。

如果您启用了自动 sidecar 注入，请执行

Zip

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

否则，在部署 sleep 应用程序前，您必须手动注入 sidecar：

Zip

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

您可以使用任何安装了 curl 的 pod 作为测试源。

  • 为了发送请求，您需要创建 SOURCE_POD 环境变量来存储源 pod 的名称：
  1. $ export SOURCE_POD=$(kubectl get pod -l app=sleep -o jsonpath={.items..metadata.name})

SNI 监控和访问策略

通过配置，让 Egress 流量流入 Egress 网关之后，就可以对其实施安全的监控和策略管理了。在本节中，会为 *.wikipedia.org 定义一个 LogEntry 以及访问策略。

  • 创建 logentry、rules 和 handlers：
  1. $ kubectl apply -f - <<EOF
  2. # Egress 访问的日志定义
  3. apiVersion: "config.istio.io/v1alpha2"
  4. kind: logentry
  5. metadata:
  6.   name: egress-access
  7.   namespace: istio-system
  8. spec:
  9.   severity: '"info"'
  10.   timestamp: context.time | timestamp("2017-01-01T00:00:00Z")
  11.   variables:
  12.     connectionEvent: connection.event | ""
  13.     source: source.labels["app"] | "unknown"
  14.     sourceNamespace: source.namespace | "unknown"
  15.     sourceWorkload: source.workload.name | ""
  16.     sourcePrincipal: source.principal | "unknown"
  17.     requestedServerName: connection.requested_server_name | "unknown"
  18.     destinationApp: destination.labels["app"] | ""
  19.   monitored_resource_type: '"UNSPECIFIED"'
  20. ---
  21. # 用于访问日志记录的 Handler
  22. apiVersion: "config.istio.io/v1alpha2"
  23. kind: stdio
  24. metadata:
  25.   name: egress-access-logger
  26.   namespace: istio-system
  27. spec:
  28.   severity_levels:
  29.     info: 0 # output log level as info
  30.   outputAsJson: true
  31. ---
  32. # 处理对 *.wikipedia.org 访问的 Rule
  33. apiVersion: "config.istio.io/v1alpha2"
  34. kind: rule
  35. metadata:
  36.   name: handle-wikipedia-access
  37.   namespace: istio-system
  38. spec:
  39.   match: source.labels["app"] == "istio-egressgateway-with-sni-proxy" && destination.labels["app"] == "" && connection.event == "open"
  40.   actions:
  41.   - handler: egress-access-logger.stdio
  42.     instances:
  43.       - egress-access.logentry
  44. EOF
  1. $ kubectl exec -it $SOURCE_POD -c sleep -- sh -c 'curl -s https://en.wikipedia.org/wiki/Main_Page | grep -o "<title>.*</title>"; curl -s https://de.wikipedia.org/wiki/Wikipedia:Hauptseite | grep -o "<title>.*</title>"'
  2. <title>Wikipedia, the free encyclopedia</title>
  3. <title>Wikipedia – Die freie Enzyklopädie</title>
  • 检查 Mixer 日志。如果 Istio 部署在 istio-system 命名空间，可以用如下命令：
  1. $ kubectl -n istio-system logs -l istio-mixer-type=telemetry -c mixer | grep 'egress-access.logentry.istio-system'
  • 定义一条策略，允许访问主机名符合 *.wikipedia.org 规则的主机，但是排除英文版：
  1. $ cat <<EOF | kubectl create -f -
  2. apiVersion: "config.istio.io/v1alpha2"
  3. kind: listchecker
  4. metadata:
  5.   name: wikipedia-checker
  6.   namespace: istio-system
  7. spec:
  8.   overrides: ["en.wikipedia.org"]  # 用静态列表作为黑名单
  9.   blacklist: true
  10. ---
  11. apiVersion: "config.istio.io/v1alpha2"
  12. kind: listentry
  13. metadata:
  14.   name: requested-server-name
  15.   namespace: istio-system
  16. spec:
  17.   value: connection.requested_server_name
  18. ---
  19. # 检查对 *.wikipedia.org 的访问
  20. apiVersion: "config.istio.io/v1alpha2"
  21. kind: rule
  22. metadata:
  23.   name: check-wikipedia-access
  24.   namespace: istio-system
  25. spec:
  26.   match: source.labels["app"] == "istio-egressgateway-with-sni-proxy" && destination.labels["app"] == ""
  27.   actions:
  28.   - handler: wikipedia-checker.listchecker
  29.     instances:
  30.       - requested-server-name.listentry
  31. EOF
  1. $ kubectl exec -it $SOURCE_POD -c sleep -- sh -c 'curl -v https://en.wikipedia.org/wiki/Main_Page'
  2. ...
  3. curl: (35) Unknown SSL protocol error in connection to en.wikipedia.org:443
  4. command terminated with exit code 35

对英文版 Wikipedia 的访问会被策略拒绝。

  1. $ kubectl exec -it $SOURCE_POD -c sleep -- sh -c 'curl -s https://es.wikipedia.org/wiki/Wikipedia:Portada | grep -o "<title>.*</title>"; curl -s https://de.wikipedia.org/wiki/Wikipedia:Hauptseite | grep -o "<title>.*</title>"'
  2. <title>Wikipedia, la enciclopedia libre</title>
  3. <title>Wikipedia – Die freie Enzyklopädie</title>

和我们计划的一样，其它语言的 Wikipedia 站点是可以访问的。

清理监控和策略定义

  1. $ kubectl delete rule handle-wikipedia-access check-wikipedia-access -n istio-system
  2. $ kubectl delete logentry egress-access -n istio-system
  3. $ kubectl delete stdio egress-access-logger -n istio-system
  4. $ kubectl delete listentry requested-server-name -n istio-system
  5. $ kubectl delete listchecker wikipedia-checker -n istio-system

监控 SNI 和源身份，并据此作出访问控制

因为已经在 Sidecar 之间、Sidecar 和 Egress 网关之间启用了双向 TLS，所以就有办法对访问外部的应用的服务身份进行监控和策略控制了。在 Kubernetes 上运行的 Istio，其身份是建立在 Service Accounts 基础之上的。这一节中将会部署两个 sleep 容器，sleep-us 和 sleep-canada，各自用不同的 Service account 运行。然后定义一个策略，允许 sleep-us 的身份访问英文和西班牙文版本的维基百科，而 sleep-canada 身份的应用可以访问英文和法文版。

  • 部署两个 sleep 容器，sleep-us 和 sleep-canada，各自使用各自的同名 Service account 运行：

ZipZip

  1. $ sed 's/: sleep/: sleep-us/g' @samples/sleep/sleep.yaml@ | kubectl apply -f -
  2. $ sed 's/: sleep/: sleep-canada/g' @samples/sleep/sleep.yaml@ | kubectl apply -f -
  3. serviceaccount "sleep-us" created
  4. service "sleep-us" created
  5. deployment "sleep-us" created
  6. serviceaccount "sleep-canada" created
  7. service "sleep-canada" created
  8. deployment "sleep-canada" created
  • 创建 logentry、rules 和 handlers：
  1. $ kubectl apply -f - <<EOF
  2. # Egress 访问的日志定义
  3. apiVersion: "config.istio.io/v1alpha2"
  4. kind: logentry
  5. metadata:
  6.   name: egress-access
  7.   namespace: istio-system
  8. spec:
  9.   severity: '"info"'
  10.   timestamp: context.time | timestamp("2017-01-01T00:00:00Z")
  11.   variables:
  12.     connectionEvent: connection.event | ""
  13.     source: source.labels["app"] | "unknown"
  14.     sourceNamespace: source.namespace | "unknown"
  15.     sourceWorkload: source.workload.name | ""
  16.     sourcePrincipal: source.principal | "unknown"
  17.     requestedServerName: connection.requested_server_name | "unknown"
  18.     destinationApp: destination.labels["app"] | ""
  19.   monitored_resource_type: '"UNSPECIFIED"'
  20. ---
  21. # Egress 访问日志的 Handler
  22. apiVersion: "config.istio.io/v1alpha2"
  23. kind: stdio
  24. metadata:
  25.   name: egress-access-logger
  26.   namespace: istio-system
  27. spec:
  28.   severity_levels:
  29.     info: 0 # output log level as info
  30.   outputAsJson: true
  31. ---
  32. # 访问 *.wikipedia.org 时应用的 Rule
  33. apiVersion: "config.istio.io/v1alpha2"
  34. kind: rule
  35. metadata:
  36.   name: handle-wikipedia-access
  37.   namespace: istio-system
  38. spec:
  39.   match: source.labels["app"] == "istio-egressgateway-with-sni-proxy" && destination.labels["app"] == "" && connection.event == "open"
  40.   actions:
  41.   - handler: egress-access-logger.stdio
  42.     instances:
  43.       - egress-access.logentry
  44. EOF
  • 从 sleep-us 向英文、德文、西班牙文和法文版本的维基百科分别发送 HTTPS 请求：
  1. $ kubectl exec -it $(kubectl get pod -l app=sleep-us -o jsonpath='{.items[0].metadata.name}') -c sleep-us -- sh -c 'curl -s https://en.wikipedia.org/wiki/Main_Page | grep -o "<title>.*</title>"; curl -s https://de.wikipedia.org/wiki/Wikipedia:Hauptseite | grep -o "<title>.*</title>"; curl -s https://es.wikipedia.org/wiki/Wikipedia:Portada | grep -o "<title>.*</title>"; curl -s https://fr.wikipedia.org/wiki/Wikip%C3%A9dia:Accueil_principal | grep -o "<title>.*</title>"'
  2. <title>Wikipedia, the free encyclopedia</title>
  3. <title>Wikipedia – Die freie Enzyklopädie</title>
  4. <title>Wikipedia, la enciclopedia libre</title>
  5. <title>Wikipédia, l'encyclopédie libre</title>
  • 查看 Mixer 日志。如果 Istio 部署在 istio-system 命名空间，可以使用如下命令：
  1. $ kubectl -n istio-system logs -l istio-mixer-type=telemetry -c mixer | grep 'egress-access.logentry.istio-system'
  2. {"level":"info","time":"2019-01-10T17:33:55.559093Z","instance":"egress-access.logentry.istio-system","connectionEvent":"open","destinationApp":"","requestedServerName":"en.wikipedia.org","source":"istio-egressgateway-with-sni-proxy","sourceNamespace":"default","sourcePrincipal":"cluster.local/ns/default/sa/sleep-us","sourceWorkload":"istio-egressgateway-with-sni-proxy"}
  3. {"level":"info","time":"2019-01-10T17:33:56.166227Z","instance":"egress-access.logentry.istio-system","connectionEvent":"open","destinationApp":"","requestedServerName":"de.wikipedia.org","source":"istio-egressgateway-with-sni-proxy","sourceNamespace":"default","sourcePrincipal":"cluster.local/ns/default/sa/sleep-us","sourceWorkload":"istio-egressgateway-with-sni-proxy"}
  4. {"level":"info","time":"2019-01-10T17:33:56.779842Z","instance":"egress-access.logentry.istio-system","connectionEvent":"open","destinationApp":"","requestedServerName":"es.wikipedia.org","source":"istio-egressgateway-with-sni-proxy","sourceNamespace":"default","sourcePrincipal":"cluster.local/ns/default/sa/sleep-us","sourceWorkload":"istio-egressgateway-with-sni-proxy"}
  5. {"level":"info","time":"2019-01-10T17:33:57.413908Z","instance":"egress-access.logentry.istio-system","connectionEvent":"open","destinationApp":"","requestedServerName":"fr.wikipedia.org","source":"istio-egressgateway-with-sni-proxy","sourceNamespace":"default","sourcePrincipal":"cluster.local/ns/default/sa/sleep-us","sourceWorkload":"istio-egressgateway-with-sni-proxy"}

注意 requestedServerName 属性，以及 sourcePrincipal，应取值为 cluster.local/ns/default/sa/sleep-us。

  • 定义一条策略，允许 sleep-us Service account 访问英文和西班牙版本的维基百科；而 sleep-canada 则可以访问英文和法文版本的维基百科。对其它语言的访问会被拦截。
  1. $ cat <<EOF | kubectl create -f -
  2. apiVersion: "config.istio.io/v1alpha2"
  3. kind: listentry
  4. metadata:
  5.   name: requested-server-name
  6.   namespace: istio-system
  7. spec:
  8.   value: connection.requested_server_name
  9. ---
  10. apiVersion: "config.istio.io/v1alpha2"
  11. kind: listchecker
  12. metadata:
  13.   name: us-wikipedia-checker
  14.   namespace: istio-system
  15. spec:
  16.   overrides: ["en.wikipedia.org", "es.wikipedia.org"]
  17.   blacklist: false
  18. ---
  19. # 访问 *.wikipedia.org 时应用的 Rule
  20. apiVersion: "config.istio.io/v1alpha2"
  21. kind: rule
  22. metadata:
  23.   name: check-us-wikipedia-access
  24.   namespace: istio-system
  25. spec:
  26.   match: source.labels["app"] == "istio-egressgateway-with-sni-proxy" && destination.labels["app"] == "" && source.principal == "cluster.local/ns/default/sa/sleep-us"
  27.   actions:
  28.   - handler: us-wikipedia-checker.listchecker
  29.     instances:
  30.       - requested-server-name.listentry
  31. ---
  32. apiVersion: "config.istio.io/v1alpha2"
  33. kind: listchecker
  34. metadata:
  35.   name: canada-wikipedia-checker
  36.   namespace: istio-system
  37. spec:
  38.   overrides: ["en.wikipedia.org", "fr.wikipedia.org"]
  39.   blacklist: false
  40. ---
  41. #  访问 *.wikipedia.org 时应用的 Rule
  42. apiVersion: "config.istio.io/v1alpha2"
  43. kind: rule
  44. metadata:
  45.   name: check-canada-wikipedia-access
  46.   namespace: istio-system
  47. spec:
  48.   match: source.labels["app"] == "istio-egressgateway-with-sni-proxy" && destination.labels["app"] == "" && source.principal == "cluster.local/ns/default/sa/sleep-canada"
  49.   actions:
  50.   - handler: canada-wikipedia-checker.listchecker
  51.     instances:
  52.       - requested-server-name.listentry
  53. EOF
  • 从 sleep-us 发送 HTTPS 流量到英文、德文、西班牙文和法文版本的维基百科：
  1. $ kubectl exec -it $(kubectl get pod -l app=sleep-us -o jsonpath='{.items[0].metadata.name}') -c sleep-us -- sh -c 'curl -s https://en.wikipedia.org/wiki/Main_Page | grep -o "<title>.*</title>"; curl -s https://de.wikipedia.org/wiki/Wikipedia:Hauptseite | grep -o "<title>.*</title>"; curl -s https://es.wikipedia.org/wiki/Wikipedia:Portada | grep -o "<title>.*</title>"; curl -s https://fr.wikipedia.org/wiki/Wikip%C3%A9dia:Accueil_principal | grep -o "<title>.*</title>";:'
  2. <title>Wikipedia, the free encyclopedia</title>
  3. <title>Wikipedia, la enciclopedia libre</title>

会看到 sleep-us 身份允许访问英文和西班牙版本。

Mixer 策略的同步可能会花几分钟，如果想要快速演示新的策略，可以删除 Mixer Policy Pod：

  1. $ kubectl delete pod -n istio-system -l istio-mixer-type=policy
  • 从 sleep-canada 发送 HTTPS 流量到英文、德文、西班牙文和法文版本的维基百科：
  1. $ kubectl exec -it $(kubectl get pod -l app=sleep-canada -o jsonpath='{.items[0].metadata.name}') -c sleep-canada -- sh -c 'curl -s https://en.wikipedia.org/wiki/Main_Page | grep -o "<title>.*</title>"; curl -s https://de.wikipedia.org/wiki/Wikipedia:Hauptseite | grep -o "<title>.*</title>"; curl -s https://es.wikipedia.org/wiki/Wikipedia:Portada | grep -o "<title>.*</title>"; curl -s https://fr.wikipedia.org/wiki/Wikip%C3%A9dia:Accueil_principal | grep -o "<title>.*</title>";:'
  2. <title>Wikipedia, the free encyclopedia</title>
  3. <title>Wikipédia, l'encyclopédie libre</title>

会看到 sleep-us 身份允许访问英文和法文版本。

清理基于 SNI 和源身份的监控和访问策略对象

  1. $ kubectl delete serviceaccount sleep-us sleep-canada
  2. $ kubectl delete service sleep-us sleep-canada
  3. $ kubectl delete deployment sleep-us sleep-canada
  4. $ kubectl delete rule handle-wikipedia-access check-us-wikipedia-access check-canada-wikipedia-access -n istio-system
  5. $ kubectl delete logentry egress-access -n istio-system
  6. $ kubectl delete stdio egress-access-logger -n istio-system
  7. $ kubectl delete listentry requested-server-name -n istio-system
  8. $ kubectl delete listchecker us-wikipedia-checker canada-wikipedia-checker -n istio-system

清理

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