Monday, July 2, 2018

Install Zabbix agent on FreeNAS 11.x

There is no official Zabbix Agent binary for FreeNAS, so it has to be compiled from source on another machine. There are several options to do so, I decided to just spin up a FreeBSD Vagrant VM to build the binary.
This post is based on the post from [1] with some enhancements

Vagrant VM

Setup VM & Build Environment

  1. Create Vagrantfile:
    Vagrant.configure("2") do |config|
      config.vm.box = "freebsd/FreeBSD-11.1-STABLE"
      config.vm.base_mac = "000000123456"
    end
    
  2. Start VM: vagrant up
  3. Enter VM: vagrant ssh
  4. Install dependecies:
    sudo pkg install -y curl autoconf automake gettext gcc pcre
    

Compile Zabbix Agent

  1. Download source:
    curl -fsSL "https://sourceforge.net/projects/zabbix/files/ZABBIX%20Latest%20Stable/3.4.14/zabbix-3.4.14.tar.gz/download" | tar zxvf -
    cd zabbix-3.4.14
    
  2. Build with TLS support for encryption:
    ./configure --enable-agent --with-openssl --enable-ipv6
    sudo make install
    
  3. Transfer compiled binary to FreeNAS system:
    scp /usr/local/sbin/zabbix_agentd root@$FREENAS_IP:/usr/local/sbin/
    
  4. Leave VM: exit
  5. Destroy VM (optional): vagrant destroy

FreeNAS

After the zabbix_agentd binary is transferred to the FreeNAS system, it’s time to SSH into it to configure the agent.

Zabbix Agent Configuration

  1. Add user:
    pw groupadd zabbix
    pw useradd zabbix -c "Daemon user for Zabbix agent" -d /nonexistent -s /usr/sbin/nologin -w no -g zabbix
    
  2. Create /etc/zabbix_agentd.conf:
    Server=$ZABBIX_SERVER_IP
    ServerActive=$ZABBIX_SERVER_IP
    Hostname=$ZABBIX_AGENT_HOSTNAME
    LogFile=/tmp/zabbix_agentd.log
    

Daemon Configuration

  1. Enable daemon:
    echo 'zabbix_agentd_enable="YES"' >> /etc/rc.conf
    
  2. Create /etc/rc.d/zabbix_agentd:
    #!/bin/sh
    
    # PROVIDE: zabbix_agentd
    # REQUIRE: DAEMON
    # KEYWORD: shutdown
    #
    # Add the following lines to /etc/rc.conf.local or /etc/rc.conf to
    # enable zabbix_agentd:
    #
    # zabbix_agentd_enable (bool): Set to NO by default.  Set it to YES to
    #         enable zabbix_agentd.
    #
    
    . /etc/rc.subr
    
    name="zabbix_agentd"
    rcvar=zabbix_agentd_enable
    start_precmd="zabbix_precmd"
    required_files="/etc/zabbix_agentd.conf"
    
    # read configuration and set defaultsc
    load_rc_config "$name"
    : ${zabbix_agentd_enable="NO"}
    #: ${zabbix_agentd_pre:=/etc/${name}.pre.sh}
    
    zabbix_agentd_conf="/etc/zabbix_agentd.conf"
    
    if [ ! -z "$zabbix_agentd_conf" ] ; then
      zabbix_agentd_flags="${zabbix_agentd_flags} -c ${zabbix_agentd_conf}"
      required_files=${zabbix_agentd_conf}
    fi
    
    zabbix_precmd()
    {
      if [ ! -z "$zabbix_agentd_pre" ] ; then
        if [ -e $zabbix_agentd_pre ] ; then
          . $zabbix_agentd_pre
        fi
      fi
    }
    
    command="/usr/local/sbin/${name}"
    
    run_rc_command "$1"  run_rc_command "$1"
    
  3. Make executable:
    chmod +x /etc/rc.d/zabbix_agentd
    
  4. Start daemon:
    /etc/rc.d/zabbix_agentd start
    
  5. Make config files persistent and survive reboots:
    cp /etc/rc.conf /conf/base/etc/
    cp /etc/rc.d/zabbix_agentd /conf/base/etc/rc.d/
    cp /etc/zabbix_agentd.conf /conf/base/etc/
     

Zabbix configuration

Use the template from the zabbix wiki for the host monitoring
http://zabbix.org/wiki/File:Template_OS_FreeNAS.xml

  1. https://docs.j7k6.org/freenas-zabbix-agent/
  2. https://blag.nullteilerfrei.de/2016/11/26/zabbix-3-0-agent-on-freebsd/
  3. https://www.haphazard.io/blog/install-nagios-nrpe-on-freenas/