Receiving error : Value should be a JSON object.

[prasul]

Hi,

I did follow the installation instructions and added the discovery option to 3.4 installation of zabbix, but now the discovery instance throws up the error "Value should be a JSON object" I can find the JSON values when I run zabbix_agent -t command via root. Can you let me know what could be wrong ?

[MogiePete]

What OS are you running? Did you copy the sudoers file and uncomment the section for your OS?

What happens when you run this command as root?

sudo -H -u zabbix zabbix_agentd -t systemd.service.discovery

[prasul]

Hi,

I am running CentOS 7 and did copy in the sudoers file - updated the permissions to 0440 as visudo recommended. and here is the log of the commands - system discovery does work OK as root, but asks for sudo password when running as zabbix user.. here are the settings:

CloudLinux release 7.5 (Viktor Gorbatko) 
[sudo] password for zabbix: 

real    0m3.033s
user    0m0.015s
sys     0m0.020s
Running as root : systemd.service.discovery                     [t|{"data":[{"{#SERVICE}": "abrt-ccpp"},{"{#SERVICE}": "abrt-oops"},{"{#SERVICE}": "abrt-vmcore"},{"{#SERVICE}": "abrt-xorg"},{"{#SERVICE}": "abrtd"},{"{#SERVICE}": "atd"},{"{#SERVICE}": "atop"},{"{#SERVICE}": "auditd"},{"{#SERVICE}": "cagefs"},{"{#SERVICE}": "chronyd"},{"{#SERVICE}": "clamd"},{"{#SERVICE}": "cpanel-dovecot-solr"},{"{#SERVICE}": "cpanel"},{"{#SERVICE}": "cpanel_dovecot_solr"},{"{#SERVICE}": "cpdavd"},{"{#SERVICE}": "cpipv6"},{"{#SERVICE}": "crond"},{"{#SERVICE}": "csf"},{"{#SERVICE}": "dmraid-activation"},{"{#SERVICE}": "dnsadmin"},{"{#SERVICE}": "dovecot"},{"{#SERVICE}": "exim"},{"{#SERVICE}": "fastmail"},{"{#SERVICE}": "httpd"},{"{#SERVICE}": "ipaliases"},{"{#SERVICE}": "irqbalance"},{"{#SERVICE}": "kdump"},{"{#SERVICE}": "kernel-triggers"},{"{#SERVICE}": "lfd"},{"{#SERVICE}": "libstoragemgmt"},{"{#SERVICE}": "lshttpd"},{"{#SERVICE}": "lsws"},{"{#SERVICE}": "lve"},{"{#SERVICE}": "lve_namespaces"},{"{#SERVICE}": "lvectl"},{"{#SERVICE}": "lvestats"},{"{#SERVICE}": "lvm2-monitor"},{"{#SERVICE}": "mailman"},{"{#SERVICE}": "maldet"},{"{#SERVICE}": "mdmonitor"},{"{#SERVICE}": "microcode"},{"{#SERVICE}": "mysqld"},{"{#SERVICE}": "named"},{"{#SERVICE}": "NetworkManager-wait-online"},{"{#SERVICE}": "nscd"},{"{#SERVICE}": "proxyexecd"},{"{#SERVICE}": "pure-authd"},{"{#SERVICE}": "pure-ftpd"},{"{#SERVICE}": "pure-uploadscript"},{"{#SERVICE}": "rhel-autorelabel-mark"},{"{#SERVICE}": "rhel-autorelabel"},{"{#SERVICE}": "rhel-configure"},{"{#SERVICE}": "rhel-dmesg"},{"{#SERVICE}": "rhel-domainname"},{"{#SERVICE}": "rhel-import-state"},{"{#SERVICE}": "rhel-loadmodules"},{"{#SERVICE}": "rhel-readonly"},{"{#SERVICE}": "rngd"},{"{#SERVICE}": "rsyslog"},{"{#SERVICE}": "securetmp"},{"{#SERVICE}": "smartd"},{"{#SERVICE}": "sshd"},{"{#SERVICE}": "sysstat"},{"{#SERVICE}": "systemd-readahead-collect"},{"{#SERVICE}": "systemd-readahead-drop"},{"{#SERVICE}": "systemd-readahead-replay"},{"{#SERVICE}": "tailwatchd"},{"{#SERVICE}": "tuned"}]}] 

 Running as zabbix user: systemd.service.discovery                     [m|ZBX_NOTSUPPORTED] [Timeout while executing a shell script.]
[root@nitro ~]# cat /etc/sudoers.d/zbx_systemd 
#Required for Zabbix to query services running under systemd
Defaults:zabbix !requiretty

#Uncomment for Enterprise Linux based hosts
Cmnd_Alias ZBX_SYSTEMD = /usr/bin/systemctl status *, /usr/bin/systemctl list-unit-files *

#Uncomment for Ubuntu based hosts 
#Cmnd_Alias ZBX_SYSTEMD = /bin/systemctl status *, /bin/systemctl list-unit-files *

zabbix ALL=(ALL:ALL) NOPASSWD:ZBX_SYSTEMD

i did try running vfs.fs.discovery as zabbix user which works OK, did try systemctl as zabbix user and it works as well.

[prasul]

Removing the sudo command does make the results show up on ssh, but zabbix still complains of missing json object. Updated the discovery interval to 1minute to test this.

[MogiePete]

It seems that you have an issue with your sudoers configuration which explains why you are being prompted for the zabbix user's password.

If I run sudo -l as the zabbix user it returns the following:

Matching Defaults entries for zabbix on zabbix:
requiretty, !visiblepw, always_set_home, env_reset, env_keep="COLORS DISPLAY HOSTNAME HISTSIZE INPUTRC KDEDIR LS_COLORS",
env_keep+="MAIL PS1 PS2 QTDIR USERNAME LANG LC_ADDRESS LC_CTYPE", env_keep+="LC_COLLATE LC_IDENTIFICATION LC_MEASUREMENT
LC_MESSAGES", env_keep+="LC_MONETARY LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE", env_keep+="LC_TIME LC_ALL LANGUAGE LINGUAS
_XKB_CHARSET XAUTHORITY", secure_path=/sbin:/bin:/usr/sbin:/usr/bin, !requiretty, !requiretty
User zabbix may run the following commands on zabbix:
(ALL : ALL) NOPASSWD: /bin/systemctl status *, /bin/systemctl list-unit-files *

However you are correct and sudo is not required to list the unit files or check the status of a service.

I am going to modify the README and remove the sudoers requirement.

[MogiePete]

@prasul

Are you experiencing the same issue or is the data now being received by Zabbix correctly?

[prasul]

@MogiePete yes, got it to work now. Thank you for your tips. I was also looking at adding a filter to list the required services instead of getting the full list of systemctl enabled services. Like create a file and cat the entries to grep from the enabled list.

[MogiePete]

Glad you were able to get it working.