[#]: collector: (lujun9972) [#]: translator: (alim0x) [#]: reviewer: (wxy) [#]: publisher: (wxy) [#]: url: (https://linux.cn/article-11440-1.html) [#]: subject: (How to Execute Commands on Remote Linux System over SSH) [#]: via: (https://www.2daygeek.com/execute-run-linux-commands-remote-system-over-ssh/) [#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/) 如何通过 SSH 在远程 Linux 系统上运行命令 ====== 我们有时可能需要在远程机器上运行一些命令。如果只是偶尔进行的操作，要实现这个目的，可以登录到远程系统上直接执行命令。但是每次都这么做的话，就有点烦人了。既然如此，有没有摆脱这种麻烦操作的更佳方案？ 是的，你可以从你本地系统上执行这些操作，而不用登录到远程系统上。这有什么好处吗？毫无疑问。这会为你节省很多好时光。 这是怎么实现的？SSH 允许你无需登录到远程计算机就可以在它上面运行命令。 **通用语法如下所示：** ``` $ ssh [用户名]@[远程主机名或 IP] [命令或脚本] ``` ### 1) 如何通过 SSH 在远程 Linux 系统上运行命令 下面的例子允许用户通过 ssh 在远程 Linux 机器上运行 [df 命令][1]。 ``` $ ssh daygeek@CentOS7.2daygeek.com df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/centos-root 27G 4.4G 23G 17% / devtmpfs 903M 0 903M 0% /dev tmpfs 920M 0 920M 0% /dev/shm tmpfs 920M 9.3M 910M 2% /run tmpfs 920M 0 920M 0% /sys/fs/cgroup /dev/sda1 1014M 179M 836M 18% /boot tmpfs 184M 8.0K 184M 1% /run/user/42 tmpfs 184M 0 184M 0% /run/user/1000 ``` ### 2) 如何通过 SSH 在远程 Linux 系统上运行多条命令 下面的例子允许用户通过 ssh 在远程 Linux 机器上一次运行多条命令。 同时在远程 Linux 系统上运行 `uptime` 命令和 `free` 命令。 ``` $ ssh daygeek@CentOS7.2daygeek.com "uptime && free -m" 23:05:10 up 10 min, 0 users, load average: 0.00, 0.03, 0.03 total used free shared buffers cached Mem: 1878 432 1445 1 100 134 -/+ buffers/cache: 197 1680 Swap: 3071 0 3071 ``` ### 3) 如何通过 SSH 在远程 Linux 系统上运行带 sudo 权限的命令 下面的例子允许用户通过 ssh 在远程 Linux 机器上运行带有 [sudo 权限][2] 的 `fdisk` 命令。 普通用户不允许执行系统二进制（`/usr/sbin/`）目录下提供的命令。用户需要 root 权限来运行它。 所以你需要 root 权限，好在 Linux 系统上运行 [fdisk 命令][3]。`which` 命令返回给定命令的完整可执行路径。 ``` $ which fdisk /usr/sbin/fdisk ``` ``` $ ssh -t daygeek@CentOS7.2daygeek.com "sudo fdisk -l" [sudo] password for daygeek: Disk /dev/sda: 32.2 GB, 32212254720 bytes, 62914560 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x000bf685 Device Boot Start End Blocks Id System /dev/sda1 * 2048 2099199 1048576 83 Linux /dev/sda2 2099200 62914559 30407680 8e Linux LVM Disk /dev/sdb: 10.7 GB, 10737418240 bytes, 20971520 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk /dev/mapper/centos-root: 29.0 GB, 28982640640 bytes, 56606720 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk /dev/mapper/centos-swap: 2147 MB, 2147483648 bytes, 4194304 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Connection to centos7.2daygeek.com closed. ``` ### 4) 如何通过 SSH 在远程 Linux 系统上运行带 sudo 权限的服务控制命令 下面的例子允许用户通过 ssh 在远程 Linux 机器上运行带有 sudo 权限的服务控制命令。 ``` $ ssh -t daygeek@CentOS7.2daygeek.com "sudo systemctl restart httpd" [sudo] password for daygeek: Connection to centos7.2daygeek.com closed. ``` ### 5) 如何通过非标准端口 SSH 在远程 Linux 系统上运行命令 下面的例子允许用户通过 ssh 在使用了非标准端口的远程 Linux 机器上运行 [hostnamectl 命令][4]。 ``` $ ssh -p 2200 daygeek@CentOS7.2daygeek.com hostnamectl Static hostname: Ubuntu18.2daygeek.com Icon name: computer-vm Chassis: vm Machine ID: 27f6c2febda84dc881f28fd145077187 Boot ID: bbeccdf932be41ddb5deae9e5f15183d Virtualization: oracle Operating System: Ubuntu 18.04.2 LTS Kernel: Linux 4.15.0-60-generic Architecture: x86-64 ``` ### 6) 如何将远程系统的输出保存到本地系统 下面的例子允许用户通过 ssh 在远程 Linux 机器上运行 [top 命令][5]，并将输出保存到本地系统。 ``` $ ssh daygeek@CentOS7.2daygeek.com "top -bc | head -n 35" > /tmp/top-output.txt ``` ``` cat /tmp/top-output.txt top - 01:13:11 up 18 min, 1 user, load average: 0.01, 0.05, 0.10 Tasks: 168 total, 1 running, 167 sleeping, 0 stopped, 0 zombie %Cpu(s): 0.0 us, 6.2 sy, 0.0 ni, 93.8 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st KiB Mem : 1882300 total, 1176324 free, 342392 used, 363584 buff/cache KiB Swap: 2097148 total, 2097148 free, 0 used. 1348140 avail Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 4943 daygeek 20 0 162052 2248 1612 R 10.0 0.1 0:00.07 top -bc 1 root 20 0 128276 6936 4204 S 0.0 0.4 0:03.08 /usr/lib/sy+ 2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [kthreadd] 3 root 20 0 0 0 0 S 0.0 0.0 0:00.25 [ksoftirqd/+ 4 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [kworker/0:+ 5 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 [kworker/0:+ 7 root rt 0 0 0 0 S 0.0 0.0 0:00.00 [migration/+ 8 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [rcu_bh] 9 root 20 0 0 0 0 S 0.0 0.0 0:00.77 [rcu_sched] 10 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 [lru-add-dr+ 11 root rt 0 0 0 0 S 0.0 0.0 0:00.01 [watchdog/0] 13 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [kdevtmpfs] 14 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 [netns] 15 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [khungtaskd] 16 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 [writeback] 17 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 [kintegrity+ 18 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 [bioset] 19 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 [bioset] 20 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 [bioset] ``` 或者你也可以使用以下格式在远程系统上运行多条命令： ``` $ ssh daygeek@CentOS7.2daygeek.com << EOF hostnamectl free -m grep daygeek /etc/passwd EOF ``` 上面命令的输出如下： ``` Pseudo-terminal will not be allocated because stdin is not a terminal. Static hostname: CentOS7.2daygeek.com Icon name: computer-vm Chassis: vm Machine ID: 002f47b82af248f5be1d67b67e03514c Boot ID: dca9a1ba06374d7d96678f9461752482 Virtualization: kvm Operating System: CentOS Linux 7 (Core) CPE OS Name: cpe:/o:centos:centos:7 Kernel: Linux 3.10.0-957.el7.x86_64 Architecture: x86-64 total used free shared buff/cache available Mem: 1838 335 1146 11 355 1314 Swap: 2047 0 2047 daygeek:x:1000:1000:2daygeek:/home/daygeek:/bin/bash ``` ### 7) 如何在远程系统上运行本地 Bash 脚本 下面的例子允许用户通过 ssh 在远程 Linux 机器上运行本地 [bash 脚本][5] `remote-test.sh`。 创建一个 shell 脚本并执行它。 ``` $ vi /tmp/remote-test.sh #!/bin/bash #Name: remote-test.sh #-------------------- uptime free -m df -h uname -a hostnamectl ``` 上面命令的输出如下： ``` $ ssh daygeek@CentOS7.2daygeek.com 'bash -s' < /tmp/remote-test.sh 01:17:09 up 22 min, 1 user, load average: 0.00, 0.02, 0.08 total used free shared buff/cache available Mem: 1838 333 1148 11 355 1316 Swap: 2047 0 2047 Filesystem Size Used Avail Use% Mounted on /dev/mapper/centos-root 27G 4.4G 23G 17% / devtmpfs 903M 0 903M 0% /dev tmpfs 920M 0 920M 0% /dev/shm tmpfs 920M 9.3M 910M 2% /run tmpfs 920M 0 920M 0% /sys/fs/cgroup /dev/sda1 1014M 179M 836M 18% /boot tmpfs 184M 12K 184M 1% /run/user/42 tmpfs 184M 0 184M 0% /run/user/1000 Linux CentOS7.2daygeek.com 3.10.0-957.el7.x86_64 #1 SMP Thu Nov 8 23:39:32 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux Static hostname: CentOS7.2daygeek.com Icon name: computer-vm Chassis: vm Machine ID: 002f47b82af248f5be1d67b67e03514c Boot ID: dca9a1ba06374d7d96678f9461752482 Virtualization: kvm Operating System: CentOS Linux 7 (Core) CPE OS Name: cpe:/o:centos:centos:7 Kernel: Linux 3.10.0-957.el7.x86_64 Architecture: x86-64 ``` 或者也可以使用管道。如果你觉得输出不太好看，再做点修改让它更优雅些。 ``` $ vi /tmp/remote-test-1.sh #!/bin/bash #Name: remote-test.sh echo "---------System Uptime--------------------------------------------" uptime echo -e "\n" echo "---------Memory Usage---------------------------------------------" free -m echo -e "\n" echo "---------Disk Usage-----------------------------------------------" df -h echo -e "\n" echo "---------Kernel Version-------------------------------------------" uname -a echo -e "\n" echo "---------HostName Info--------------------------------------------" hostnamectl echo "------------------------------------------------------------------" ``` 上面脚本的输出如下： ``` $ cat /tmp/remote-test.sh | ssh daygeek@CentOS7.2daygeek.com Pseudo-terminal will not be allocated because stdin is not a terminal. ---------System Uptime-------------------------------------------- 03:14:09 up 2:19, 1 user, load average: 0.00, 0.01, 0.05 ---------Memory Usage--------------------------------------------- total used free shared buff/cache available Mem: 1838 376 1063 11 398 1253 Swap: 2047 0 2047 ---------Disk Usage----------------------------------------------- Filesystem Size Used Avail Use% Mounted on /dev/mapper/centos-root 27G 4.4G 23G 17% / devtmpfs 903M 0 903M 0% /dev tmpfs 920M 0 920M 0% /dev/shm tmpfs 920M 9.3M 910M 2% /run tmpfs 920M 0 920M 0% /sys/fs/cgroup /dev/sda1 1014M 179M 836M 18% /boot tmpfs 184M 12K 184M 1% /run/user/42 tmpfs 184M 0 184M 0% /run/user/1000 tmpfs 184M 0 184M 0% /run/user/0 ---------Kernel Version------------------------------------------- Linux CentOS7.2daygeek.com 3.10.0-957.el7.x86_64 #1 SMP Thu Nov 8 23:39:32 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux ---------HostName Info-------------------------------------------- Static hostname: CentOS7.2daygeek.com Icon name: computer-vm Chassis: vm Machine ID: 002f47b82af248f5be1d67b67e03514c Boot ID: dca9a1ba06374d7d96678f9461752482 Virtualization: kvm Operating System: CentOS Linux 7 (Core) CPE OS Name: cpe:/o:centos:centos:7 Kernel: Linux 3.10.0-957.el7.x86_64 Architecture: x86-64 ``` ### 8) 如何同时在多个远程系统上运行多条指令 下面的 bash 脚本允许用户同时在多个远程系统上运行多条指令。使用简单的 `for` 循环实现。 为了实现这个目的，你可以尝试 [PSSH 命令][7] 或 [ClusterShell 命令][8] 或 [DSH 命令][9]。 ``` $ vi /tmp/multiple-host.sh for host in CentOS7.2daygeek.com CentOS6.2daygeek.com do ssh daygeek@CentOS7.2daygeek.com${host} "uname -a;uptime;date;w" done ``` 上面脚本的输出如下： ``` $ sh multiple-host.sh Linux CentOS7.2daygeek.com 3.10.0-957.el7.x86_64 #1 SMP Thu Nov 8 23:39:32 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux 01:33:57 up 39 min, 1 user, load average: 0.07, 0.06, 0.06 Wed Sep 25 01:33:57 CDT 2019 01:33:57 up 39 min, 1 user, load average: 0.07, 0.06, 0.06 USER TTY FROM daygeek@CentOS7.2daygeek.com IDLE JCPU PCPU WHAT daygeek pts/0 192.168.1.6 01:08 23:25 0.06s 0.06s -bash Linux CentOS6.2daygeek.com 2.6.32-754.el6.x86_64 #1 SMP Tue Jun 19 21:26:04 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux 23:33:58 up 39 min, 0 users, load average: 0.00, 0.00, 0.00 Tue Sep 24 23:33:58 MST 2019 23:33:58 up 39 min, 0 users, load average: 0.00, 0.00, 0.00 USER TTY FROM daygeek@CentOS7.2daygeek.com IDLE JCPU PCPU WHAT ``` ### 9) 如何使用 sshpass 命令添加一个密码 如果你觉得每次输入密码很麻烦，我建议你视你的需求选择以下方法中的一项来解决这个问题。 如果你经常进行类似的操作，我建议你设置 [免密码认证][10]，因为它是标准且永久的解决方案。 如果你一个月只是执行几次这些任务，我推荐你使用 `sshpass` 工具。只需要使用 `-p` 参数选项提供你的密码即可。 ``` $ sshpass -p '在这里输入你的密码' ssh -p 2200 daygeek@CentOS7.2daygeek.com ip a 1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 08:00:27:18:90:7f brd ff:ff:ff:ff:ff:ff inet 192.168.1.12/24 brd 192.168.1.255 scope global dynamic eth0 valid_lft 86145sec preferred_lft 86145sec inet6 fe80::a00:27ff:fe18:907f/64 scope link tentative dadfailed valid_lft forever preferred_lft forever ``` -------------------------------------------------------------------------------- via: https://www.2daygeek.com/execute-run-linux-commands-remote-system-over-ssh/ 作者：[Magesh Maruthamuthu][a] 选题：[lujun9972][b] 译者：[alim0x](https://github.com/alim0x) 校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 [a]: https://www.2daygeek.com/author/magesh/ [b]: https://github.com/lujun9972 [1]: https://www.2daygeek.com/linux-check-disk-space-usage-df-command/ [2]: https://www.2daygeek.com/how-to-configure-sudo-access-in-linux/ [3]: https://www.2daygeek.com/linux-fdisk-command-to-manage-disk-partitions/ [4]: https://www.2daygeek.com/four-methods-to-change-the-hostname-in-linux/ [5]: https://www.2daygeek.com/understanding-linux-top-command-output-usage/ [6]: https://www.2daygeek.com/category/shell-script/ [7]: https://www.2daygeek.com/pssh-parallel-ssh-run-execute-commands-on-multiple-linux-servers/ [8]: https://www.2daygeek.com/clustershell-clush-run-commands-on-cluster-nodes-remote-system-in-parallel-linux/ [9]: https://www.2daygeek.com/dsh-run-execute-shell-commands-on-multiple-linux-servers-at-once/ [10]: https://www.2daygeek.com/configure-setup-passwordless-ssh-key-based-authentication-linux/