---
description: 能力机制（Capability）是 Linux 内核一个强大的特性，可以提供细粒度的权限访问控制。
---

# 入门操作测试2

## 测试2：

以`entrypoint`指定命令运行busybox容器：

```
sudo docker run --name bbox2 --rm -it --entrypoint /bin/sh busybox
```

这里添加的`--rm` 参数，是实现退出这个容器后马上把它删除

默认情况下，容器被严格限制只允许使用内核的一部分能力，根据实际情况，可以使用参数`--cap-add`和 `--cap-drop`来控制容器的能力。例如：

```
sudo docker run --name bbox2 --rm -it --cap-add NET_ADMIN --cap-drop CHOWN --entrypoint /bin/sh busybox
```

更多用于docker的capability key如下表：（来自[https://docs.docker.com/engine/reference/run/](https://docs.docker.com/engine/reference/run/)）

| Capability Key     | Capability Description                                                                                                        |
| ------------------ | ----------------------------------------------------------------------------------------------------------------------------- |
| SETPCAP            | Modify process capabilities.                                                                                                  |
| MKNOD              | Create special files using mknod(2).                                                                                          |
| AUDIT\_WRITE       | Write records to kernel auditing log.                                                                                         |
| CHOWN              | Make arbitrary changes to file UIDs and GIDs (see chown(2)).                                                                  |
| NET\_RAW           | Use RAW and PACKET sockets.                                                                                                   |
| DAC\_OVERRIDE      | Bypass file read, write, and execute permission checks.                                                                       |
| FOWNER             | Bypass permission checks on operations that normally require the file system UID of the process to match the UID of the file. |
| FSETID             | Don’t clear set-user-ID and set-group-ID permission bits when a file is modified.                                             |
| KILL               | Bypass permission checks for sending signals.                                                                                 |
| SETGID             | Make arbitrary manipulations of process GIDs and supplementary GID list.                                                      |
| SETUID             | Make arbitrary manipulations of process UIDs.                                                                                 |
| NET\_BIND\_SERVICE | Bind a socket to internet domain privileged ports (port numbers less than 1024).                                              |
| SYS\_CHROOT        | Use chroot(2), change root directory.                                                                                         |
| SETFCAP            | Set file capabilities.                                                                                                        |

| Capability Key    | Capability Description                                                                                          |
| ----------------- | --------------------------------------------------------------------------------------------------------------- |
| SYS\_MODULE       | Load and unload kernel modules.                                                                                 |
| SYS\_RAWIO        | Perform I/O port operations (iopl(2) and ioperm(2)).                                                            |
| SYS\_PACCT        | Use acct(2), switch process accounting on or off.                                                               |
| SYS\_ADMIN        | Perform a range of system administration operations.                                                            |
| SYS\_NICE         | Raise process nice value (nice(2), setpriority(2)) and change the nice value for arbitrary processes.           |
| SYS\_RESOURCE     | Override resource Limits.                                                                                       |
| SYS\_TIME         | Set system clock (settimeofday(2), stime(2), adjtimex(2)); set real-time (hardware) clock.                      |
| SYS\_TTY\_CONFIG  | Use vhangup(2); employ various privileged ioctl(2) operations on virtual terminals.                             |
| AUDIT\_CONTROL    | Enable and disable kernel auditing; change auditing filter rules; retrieve auditing status and filtering rules. |
| MAC\_ADMIN        | Allow MAC configuration or state changes. Implemented for the Smack LSM.                                        |
| MAC\_OVERRIDE     | Override Mandatory Access Control (MAC). Implemented for the Smack Linux Security Module (LSM).                 |
| NET\_ADMIN        | Perform various network-related operations.                                                                     |
| SYSLOG            | Perform privileged syslog(2) operations.                                                                        |
| DAC\_READ\_SEARCH | Bypass file read permission checks and directory read and execute permission checks.                            |
| LINUX\_IMMUTABLE  | Set the FS\_APPEND\_FL and FS\_IMMUTABLE\_FL i-node flags.                                                      |
| NET\_BROADCAST    | Make socket broadcasts, and listen to multicasts.                                                               |
| IPC\_LOCK         | Lock memory (mlock(2), mlockall(2), mmap(2), shmctl(2)).                                                        |
| IPC\_OWNER        | Bypass permission checks for operations on System V IPC objects.                                                |
| SYS\_PTRACE       | Trace arbitrary processes using ptrace(2).                                                                      |
| SYS\_BOOT         | Use reboot(2) and kexec\_load(2), reboot and load a new kernel for later execution.                             |
| LEASE             | Establish leases on arbitrary files (see fcntl(2)).                                                             |
| WAKE\_ALARM       | Trigger something that will wake up the system.                                                                 |
| BLOCK\_SUSPEND    | Employ features that can block system suspend.                                                                  |

更多关于Linux Capability的知识点，可以访问这个网页：

[http://man7.org/linux/man-pages/man7/capabilities.7.html](http://man7.org/linux/man-pages/man7/capabilities.7.html)









