借助3款K8S原生控件，保护你的云原生应用

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"随着越来越多的企业开始采用容器技术，他们正在面临一个重大挑战——如何保护容器应用程序的安全？比起存储、网络和监控，安全常常是一个被积压已久的问题。再加上需要对员工进行Kubernetes相关的培训，对安全问题的关注已经远远滞后了。事实上，The New Stack发布的一项调查显示，近50%的Kubernetes用户表示，安全是他们尚未解决的首要问题。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在本文中，我们将深入了解Kubernetes所面临的安全威胁并展示保护集群的最佳实践，然后提供一些有用的工具以帮助开发人员维护集群安全。这些工具包括："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Rancher Kubernetes Engine(RKE)，以实现声明式部署"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"KubeLinter，用于以开发者为中心的安全检查"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"StackRox，在构建、部署和运行时执行安全策略"}]}]}]},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"工具介绍"}]},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"Rancher Kubernetes Engine(RKE)"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"RKE是一个经过CNCF认证的Kubernetes发行版，可以在Docker容器内完整运行。它通过移除大多数的主机依赖项并提供一个部署、升级和回滚的稳定路径，解决了Kubernetes安装过于复杂的问题。RKE使用声明式YAML文件来配置和创建Kubernetes环境。这可以实现可重现的本地或远程环境。"}]},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"KubeLinter"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"KubeLinter是一个静态的分析工具，它可以查看Kubernetes 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Engine包含了数百个内置控制，以执行DevOps和安全最佳实践、CIS基准和NIST等行业标准、容器和Kubernetes运行时安全的配置管理。StackRox对您的工作负载进行剖析，使您能够对工作负载的安全性做出明智的决定。"}]},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"组合使用"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"RKE、KubeLinter和StackRox使您能够部署可重现的安全集群、可视化配置文件和访问安全漏洞，并创建声明式安全策略。接下来，我们来谈谈这些应用程序如何共同应对安全威胁。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"评估安全风险"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"我们先来关注一下Kubernetes的攻击载体。微软最近发布了一个基于MITRE ATT&CK框架的Kubernetes攻击矩阵："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"underline"}],"text":"https:\/\/www.microsoft.com\/security\/blog\/2020\/04\/02\/attack-matrix-kubernetes\/"}]},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/56\/563830ddd779e98db033bae7b6bc7093.jpeg","alt":"图片","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"该框架针对Kubernetes进行了调整，并基于真实世界的观察和案例。幸运的是，存在一些策略可以缓解所有不同的问题。首先，我们可以从hardening我们的Kubernetes控制平面开始。之后，我们将把重点转移到保护我们运行的容器工作负载的安全上。"}]},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"控制平面Hardening"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Kubernetes控制平面包括以下组件："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Kubernetes 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Server的安全成为人们最关心的问题。在此前的K8S版本中，只要升级到较新的版本就可以修复一些特定的漏洞。然而，你也可以控制以下hardening任务："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"启用基于角色控制访问（RBAC）"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"确保所有API流量是TLS加密的"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"启用审计日志"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"为所有K8S API客户端设置身份验证"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"借助诸如RKE等开发工具，可以很轻松地设置这种声明式格式的集群。以下是一个默认的RKE config.yml.file代码段。从中可以看到，我们能够默认启用审计日志、TLS（在Kubernetes组件之间）以及RBAC。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"text"},"content":[{"type":"text","text":"\n kube-api:\n image: \"\"\n extra_args: {}\n extra_binds: []\n extra_env: []\n win_extra_args: {}\n win_extra_binds: []\n win_extra_env: []\n service_cluster_ip_range: 10.43.0.0\/16\n service_node_port_range: \"\"\n pod_security_policy: false\n always_pull_images: false\n secrets_encryption_config: null\n audit_log: null\n admission_configuration: null\n event_rate_limit: null\n…\nauthentication:\n strategy: x509\n sans: []\n webhook: null\n…\nauthorization:\n mode: rbac\n options: 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\/etc\/kubernetes\/manifests\/kube-scheduler.yaml"}]},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"kube-controller-manager"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Kubernetes系统调节器，即kube-controller-manager，是一个使用核心控制循环调节系统的守护进程。保护controller的安全，需要采取与scheduler类似的策略："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"设置一个与API 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