153 lines
5.7 KiB
Markdown
153 lines
5.7 KiB
Markdown
---
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layout: blog
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title: “Kubernetes 1.25：对使用用户名字空间运行 Pod 提供 Alpha 支持”
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date: 2022-10-03
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slug: userns-alpha
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---
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<!--
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layout: blog
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title: "Kubernetes 1.25: alpha support for running Pods with user namespaces"
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date: 2022-10-03
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slug: userns-alpha
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-->
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<!--
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**Authors:** Rodrigo Campos (Microsoft), Giuseppe Scrivano (Red Hat)
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-->
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**作者:** Rodrigo Campos（Microsoft）、Giuseppe Scrivano（Red Hat）
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<!--
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Kubernetes v1.25 introduces the support for user namespaces.
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-->
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Kubernetes v1.25 引入了对用户名字空间的支持。
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<!--
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This is a major improvement for running secure workloads in
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Kubernetes. Each pod will have access only to a limited subset of the
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available UIDs and GIDs on the system, thus adding a new security
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layer to protect from other pods running on the same system.
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-->
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这是在 Kubernetes 中运行安全工作负载的一项重大改进。
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每个 Pod 只能访问系统上可用 UID 和 GID 的有限子集，
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因此添加了一个新的安全层来保护 Pod 免受运行在同一系统上的其他 Pod 的影响。
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<!--
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## How does it work?
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A process running on Linux can use up to 4294967296 different UIDs and
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GIDs.
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User namespaces is a Linux feature that allows mapping a set of users
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in the container to different users in the host, thus restricting what
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IDs a process can effectively use.
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Furthermore, the capabilities granted in a new user namespace do not
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apply in the host initial namespaces.
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-->
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## 它是如何工作的？ {#how-does-it-work}
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在 Linux 上运行的进程最多可以使用 4294967296 个不同的 UID 和 GID。
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用户名字空间是 Linux 的一项特性，它允许将容器中的一组用户映射到主机中的不同用户，
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从而限制进程可以实际使用的 ID。
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此外，在新用户名字空间中授予的权能不适用于主机初始名字空间。
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<!--
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## Why is it important?
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There are mainly two reasons why user namespaces are important:
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- improve security since they restrict the IDs a pod can use, so each
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pod can run in its own separate environment with unique IDs.
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- enable running workloads as root in a safer manner.
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In a user namespace we can map the root user inside the pod to a
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non-zero ID outside the container, containers believe in running as
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root while they are a regular unprivileged ID from the host point of
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view.
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The process can keep capabilities that are usually restricted to
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privileged pods and do it in a safe way since the capabilities granted
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in a new user namespace do not apply in the host initial namespaces.
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-->
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## 它为什么如此重要？ {#why-is-it-important}
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用户名字空间之所以重要，主要有两个原因：
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- 提高安全性。因为它们限制了 Pod 可以使用的 ID，
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因此每个 Pod 都可以在其自己的具有唯一 ID 的单独环境中运行。
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- 以更安全的方式使用 root 身份运行工作负载。
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在用户名字空间中，我们可以将 Pod 内的 root 用户映射到容器外的非零 ID，
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容器将认为是 root 身份在运行，而从主机的角度来看，它们是常规的非特权 ID。
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该进程可以保留通常仅限于特权 Pod 的功能，并以安全的方式执行这类操作，
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因为在新用户名字空间中授予的功能不适用于主机初始名字空间。
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<!--
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## How do I enable user namespaces?
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At the moment, user namespaces support is opt-in, so you must enable
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it for a pod setting `hostUsers` to `false` under the pod spec stanza:
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-->
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## 如何启用用户名字空间 {#how-do-i-enable-user-namespaces}
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目前，对用户名字空间的支持是可选的，因此你必须在 Pod 规约部分将
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`hostUsers` 设置为 `false` 以启用用户名字空间：
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```
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apiVersion: v1
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kind: Pod
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spec:
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hostUsers: false
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containers:
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- name: nginx
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image: docker.io/nginx
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```
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<!--
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The feature is behind a feature gate, so make sure to enable
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the `UserNamespacesStatelessPodsSupport` gate before you can use
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the new feature.
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-->
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该特性目前还处于 Alpha 阶段，默认是禁用的，因此在使用此新特性之前，
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请确保启用了 `UserNamespacesStatelessPodsSupport` 特性门控。
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<!--
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The runtime must also support user namespaces:
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* containerd: support is planned for the 1.7 release. See containerd
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issue [#7063][containerd-userns-issue] for more details.
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* CRI-O: v1.25 has support for user namespaces.
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Support for this in `cri-dockerd` is [not planned][CRI-dockerd-issue] yet.
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-->
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此外，运行时也必须支持用户名字空间：
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* Containerd：计划在 1.7 版本中提供支持。
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进一步了解，请参阅 Containerd issue [#7063][containerd-userns-issue]。
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* CRI-O：v1.25 支持用户名字空间。
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`cri-dockerd` 对用户名字空间的支持[尚无计划][CRI-dockerd-issue]。
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[CRI-dockerd-issue]: https://github.com/Mirantis/cri-dockerd/issues/74
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[containerd-userns-issue]: https://github.com/containerd/containerd/issues/7063
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<!--
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## How do I get involved?
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You can reach SIG Node by several means:
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- Slack: [#sig-node](https://kubernetes.slack.com/messages/sig-node)
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- [Mailing list](https://groups.google.com/forum/#!forum/kubernetes-sig-node)
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- [Open Community Issues/PRs](https://github.com/kubernetes/community/labels/sig%2Fnode)
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You can also contact us directly:
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- GitHub / Slack: @rata @giuseppe
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-->
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## 我如何参与？ {#how-do-i-get-involved}
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你可以通过多种方式联系 SIG Node：
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- Slack: [#sig-node](https://kubernetes.slack.com/messages/sig-node)
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- [邮件列表](https://groups.google.com/forum/#!forum/kubernetes-sig-node)
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- [开源社区 Issue/PR](https://github.com/kubernetes/community/labels/sig%2Fnode)
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你也可以直接联系我们：
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- GitHub / Slack: @rata @giuseppe
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- [开源社区 Issue/PR](https://github.com/kubernetes/community/labels/sig%2Fnode)
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