website/content/zh/docs/tasks/configure-pod-container/share-process-namespace.md

---
title: 在 Pod 中的容器之间共享进程命名空间
min-kubernetes-server-version: v1.10
content_template: templates/task
weight: 160
---
<!--
---
title: Share Process Namespace between Containers in a Pod
min-kubernetes-server-version: v1.10
reviewers:
- verb
- yujuhong
- dchen1107
content_template: templates/task
weight: 160
---
-->

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{{< feature-state state="beta" >}}

<!--
This page shows how to configure process namespace sharing for a pod. When
process namespace sharing is enabled, processes in a container are visible
to all other containers in that pod.
-->
此页面展示如何为 pod 配置进程命名空间共享。
当启用进程命名空间共享时，容器中的进程对该 pod 中的所有其他容器都是可见的。

<!--
You can use this feature to configure cooperating containers, such as a log
handler sidecar container, or to troubleshoot container images that don't
include debugging utilities like a shell.
-->
您可以使用此功能来配置协作容器，比如日志处理 sidecar 容器，或者对那些不包含诸如 shell 等调试实用工具的镜像进行故障排查。

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{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}

<!--
Process Namespace Sharing is a **beta** feature that is enabled by default. It
may be disabled by setting `--feature-gates=PodShareProcessNamespace=false`.
-->
进程命名空间共享是默认启用的 **beta** 版功能。
您可以通过设置 `--feature-gates=PodShareProcessNamespace=false` 禁用此功能。

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<!--
## Configure a Pod
-->
## 配置 Pod

<!--
Process Namespace Sharing is enabled using the `ShareProcessNamespace` field of
`v1.PodSpec`. For example:
-->
进程命名空间共享使用 `v1.PodSpec` 中的 `ShareProcessNamespace` 字段启用。例如：

{{< codenew file="pods/share-process-namespace.yaml" >}}

<!--
1. Create the pod `nginx` on your cluster:

        kubectl create -f https://k8s.io/examples/pods/share-process-namespace.yaml

2. Attach to the `shell` container and run `ps`:

        ```
        kubectl attach -it nginx -c shell
        ```

        If you don't see a command prompt, try pressing enter.

        ```
        / # ps ax
        PID   USER     TIME  COMMAND
            1 root      0:00 /pause
            8 root      0:00 nginx: master process nginx -g daemon off;
           14 101       0:00 nginx: worker process
           15 root      0:00 sh
           21 root      0:00 ps ax
        ```
-->
1. 在集群中创建 `nginx` pod：

        kubectl create -f https://k8s.io/examples/pods/share-process-namespace.yaml

2. 获取容器 `shell`，执行 `ps`：

        ```
        kubectl attach -it nginx -c shell
        ```

        如果没有看到命令提示符，请按 enter 回车键。

        ```
        / # ps ax
        PID   USER     TIME  COMMAND
            1 root      0:00 /pause
            8 root      0:00 nginx: master process nginx -g daemon off;
           14 101       0:00 nginx: worker process
           15 root      0:00 sh
           21 root      0:00 ps ax
        ```
<!--
You can signal processes in other containers. For example, send `SIGHUP` to
nginx to restart the worker process. This requires the `SYS_PTRACE` capability.
-->
您可以在其他容器中对进程发出信号。例如，发送 `SIGHUP` 到 nginx 以重启工作进程。这需要 `SYS_PTRACE` 功能。

        / # kill -HUP 8
        / # ps ax
        PID   USER     TIME  COMMAND
            1 root      0:00 /pause
            8 root      0:00 nginx: master process nginx -g daemon off;
           15 root      0:00 sh
           22 101       0:00 nginx: worker process
           23 root      0:00 ps ax

<!--
It's even possible to access another container image using the
`/proc/$pid/root` link.
-->
甚至可以使用 `/proc/$pid/root` 链接访问另一个容器镜像。

        / # head /proc/8/root/etc/nginx/nginx.conf

        user  nginx;
        worker_processes  1;

        error_log  /var/log/nginx/error.log warn;
        pid        /var/run/nginx.pid;


        events {
            worker_connections  1024;

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<!--
## Understanding Process Namespace Sharing
-->
## 理解进程命名空间共享

<!--
Pods share many resources so it makes sense they would also share a process
namespace. Some container images may expect to be isolated from other
containers, though, so it's important to understand these differences:
-->
Pod 共享许多资源，因此它们共享进程命名空间是很有意义的。
不过，有些容器镜像可能希望与其他容器隔离，因此了解这些差异很重要:

<!--
1. **The container process no longer has PID 1.** Some container images refuse
   to start without PID 1 (for example, containers using `systemd`) or run
   commands like `kill -HUP 1` to signal the container process. In pods with a
   shared process namespace, `kill -HUP 1` will signal the pod sandbox.
   (`/pause` in the above example.)

2. **Processes are visible to other containers in the pod.** This includes all
   information visible in `/proc`, such as passwords that were passed as arguments
   or environment variables. These are protected only by regular Unix permissions.

3. **Container filesystems are visible to other containers in the pod through the
   `/proc/$pid/root` link.** This makes debugging easier, but it also means
   that filesystem secrets are protected only by filesystem permissions.
-->

1. **容器进程不再具有 PID 1。** 在没有 PID 1 的情况下，一些容器镜像拒绝启动（例如，使用 `systemd` 的容器)，或者拒绝执行 `kill -HUP 1` 之类的命令来通知容器进程。在具有共享进程命名空间的 pod 中，`kill -HUP 1` 将通知 pod 沙箱（在上面的例子中是 `/pause`）。

2. **进程对 pod 中的其他容器可见。** 这包括 `/proc` 中可见的所有信息，例如作为参数或环境变量传递的密码。这些仅受常规 Unix 权限的保护。

3. **容器文件系统通过 `/proc/$pid/root` 链接对 pod 中的其他容器可见。** 这使调试更加容易，但也意味着文件系统安全性只受文件系统权限的保护。

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