9 SSH检查

Overview

概述

SSH checks are performed as agent-less monitoring. Zabbix agent is not needed for SSH checks.

SSH检查不依赖于Zabbix agent，可对无agent代理的设备进行监控。

To perform SSH checks Zabbix server must be initially configured with SSH2 support.

要执行SSH检查操作，Zabbix server必须支持SSH2。 <note important>libssh2库的最低版本是1.0.0. :::

Configuration

配置

Passphrase authentication

密码验证

SSH checks provide two authentication methods, a user/password pair and key-file based.

SSH检查提供了两种身份验证方式，一种是用户/密码对，另一种是基于密钥文件的验证方式。

If you do not intend to use keys, no additional configuration is required, besides linking libssh2 to Zabbix, if you're building from source.

如果你不打算使用密钥，除了将libssh2连接到Zabbix，就不需要额外的配置了（如果是源码安装）。

Key file authentication

密钥文件认证

To use key based authentication for SSH items, certain changes to the server configuration are required.

要对SSH监控项使用基于密钥的身份验证，需要对服务器配置进行某些更改。

Open the Zabbix server configuration file (zabbix_server.conf) as root and look for the following line:

以root身份打开Zabbix server的配置文件，查找以下行

# SSHKeyLocation=
       
       # SSHKeyLocation=

Uncomment it and set full path to a folder where public and private keys will be located:

取消注释，配置公钥和私钥所在文件夹的完整路径：

SSHKeyLocation=/home/zabbix/.ssh
       
       
       SSHKeyLocation=/home/zabbix/.ssh

Save the file and restart zabbix_server afterwards.

保存文件并重启zabbix_server服务

/home/zabbix here is the home directory for the zabbix user account and .ssh is a directory where by default public and private keys will be generated by a ssh-keygen command inside the home directory.

/home/zabbix 在这里是 zabbix 用户的主目录；.ssh是一个目录，由 ssh-keygen 这个命令产生的公钥和密钥将默认放到这个目录中。

Usually installation packages of zabbix-server from different OS distributions create the zabbix user account with a home directory in not very well-known places (as for system accounts). For example, for CentOS it's /var/lib/zabbix, for Debian it's /var/run/zabbix.

不同发行版操作系统的zabbix-server安装程序，会在不太明显的地方（与系统账户一样）创建一个带有主目录的zabbix用户账户。例如，对于CentOS系统，在 /var/lib/zabbix 位置，而Debian系统则是在 /var/run/zabbix 。

Before starting to generate the keys, an approach to reallocate the home directory to a better known place (intuitively expected) could be considered. This will correspond with the SSHKeyLocation Zabbix server configuration parameter mentioned above.

在生成密钥之前，可以考虑将主目录重新分配到更熟悉的地方（更为直观），与上述提到的 Zabbix server配置中 SSHKeyLocation 的参数对应。

These steps can be skipped if zabbix account has been added manually according to the installation section because in this case most likely the home directory is already located at /home/zabbix.

如果根据 安装章节 手动添加了zabbix账户，则这些步骤可以省略，因为在这种情况下，主目录很可能已经是位于 /home/zabbix 。

To change the setting for the zabbix user account all working processes which are using it have to be stopped:

# service zabbix-agent stop
       # service zabbix-server stop

要更改 zabbix 账户的设置，必须停止所有正在使用它的进程：

# service zabbix-agent stop
       # service zabbix-server stop

To change the home directory location with an attempt to move it (if it exists) a command should be executed:

# usermod -m -d /home/zabbix zabbix

要更改主目录的位置，以尝试移动它（如果存在），要执行一条命令：

# usermod -m -d /home/zabbix zabbix

It's absolutely possible that a home directory did not exist in the old place (in the CentOS for example), so it should be created at the new place. A safe attempt to do that is:

# test -d /home/zabbix || mkdir /home/zabbix

在旧的地方不存在主目录是完全可能的，因此需要在新的地方创建。一个安全的做法是：

# test -d /home/zabbix || mkdir /home/zabbix

To be sure that all is secure, additional commands could be executed to set permissions to the home directory:

# chown zabbix:zabbix /home/zabbix
       # chmod 700 /home/zabbix

为确保一切都是安全的，可以执行其他命令来设置主目录的权限：

# chown zabbix:zabbix /home/zabbix
       # chmod 700 /home/zabbix

Previously stopped processes now can be started again:

# service zabbix-agent start
       # service zabbix-server start

之前被停止的进程现在可以重新启动了：

# service zabbix-agent start
       # service zabbix-server start

Now steps to generate public and private keys can be performed by a command:

现在，可以通过如下命令来生成公钥和私钥：

# sudo -u zabbix ssh-keygen -t rsa
       Generating public/private rsa key pair.
       Enter file in which to save the key (/home/zabbix/.ssh/id_rsa): 
       Created directory '/home/zabbix/.ssh'.
       Enter passphrase (empty for no passphrase): 
       Enter same passphrase again: 
       Your identification has been saved in /home/zabbix/.ssh/id_rsa.
       Your public key has been saved in /home/zabbix/.ssh/id_rsa.pub.
       The key fingerprint is:
       90:af:e4:c7:e3:f0:2e:5a:8d:ab:48:a2:0c:92:30:b9 zabbix@it0
       The key's randomart image is:
       +--[ RSA 2048]----+
       |                 |
       |       .         |
       |      o          |
       | .     o         |
       |+     . S        |
       |.+   o =         |
       |E .   * =        |
       |=o . ..* .       |
       |... oo.o+        |
       +-----------------+

Note: public and private keys (id_rsa.pub and id_rsa respectively) have been generated by default in the /home/zabbix/.ssh directory which corresponds to the Zabbix server SSHKeyLocation configuration parameter.

请注意：在默认情况下，公钥和私钥(分别为 id_rsa.pub 和 id_rsa )生成在 /home/zabbix/.ssh 目录，这与Zabbix server配置中 SSHKeyLocation 的参数是对应的。

<note important>ssh-keygen工具和SSH服务器除了“rsa”之外，也可支持其他密钥类型，但Zabbix使用的libssh2可能不支持它们。 :::

Shell configuration form

Shell配置方式

This step should be performed only once for every host that will be monitored by SSH checks.

对于每台被SSH检测的主机，此步骤只需要执行一次。

By using the following command the public key file can be installed on a remote host 10.10.10.10 so that then SSH checks can be performed with a root account:

通过使用以下命令，公钥 会安装到远程主机 10.10.10.10 上，以便可以使用 root 账户执行SSH检查：

# sudo -u zabbix ssh-copy-id [email protected]
       The authenticity of host '10.10.10.10 (10.10.10.10)' can't be established.
       RSA key fingerprint is 38:ba:f2:a4:b5:d9:8f:52:00:09:f7:1f:75:cc:0b:46.
       Are you sure you want to continue connecting (yes/no)? yes
       Warning: Permanently added '10.10.10.10' (RSA) to the list of known hosts.
       [email protected]'s password: 
       Now try logging into the machine, with "ssh '[email protected]'", and check in:
         .ssh/authorized_keys
       to make sure we haven't added extra keys that you weren't expecting.

Now it's possible to check the SSH login using the default private key (/home/zabbix/.ssh/id_rsa) for zabbix user account:

# sudo -u zabbix ssh [email protected]

现在可以使用 zabbix 用户的默认私钥 (/home/zabbix/.ssh/id_rsa) 检查SSH登陆了：

# sudo -u zabbix ssh [email protected]

If the login is successful, then the configuration part in the shell is finished and remote SSH session can be closed.

如果登陆成功，那么Shell中的配置部分就完成了，并可以关闭远程SSH会话。

Item configuration

监控项配置

Actual command(s) to be executed must be placed in the Executed script field in the item configuration.
Multiple commands can be executed one after another by placing them on a new line. In this case returned values also will be formatted as multi lined.
要执行的实际命令必须放在监控项配置的 执行脚本 中。
如要执行多条命令，在执行脚本字段中一行写一条，命令将会逐条执行。这种情况下，返回值也将为多行显示。

All mandatory input fields are marked with a red asterisk.

所有标有红色星号的为必填项。

The fields that require specific information for SSH items are:

需要为SSH监控项提供特定信息的字段是：

<note important>libssh2库可能会将可执行脚本截断到~32kB :::