How to capture comments returned by script

[ashuji]

Hi,

For custom ITEMs, in zabbix we create ITEM, and ITEM runs a custom scripts and capture value returned by the script (0 or 1 etc.) and store it in its DB. Based on this value returned, zabbix trigger turns ON/OFF.

But how to configure an ITEM to also capture comments returned by any particular script.

Suppose if we compose a script which check if perticular file is writable or not by zabbix user, following are the contents:

ITEM Name: check_file
TYPE: zabbix_agent
Type of info: FLOAT
Interval: 300 (5 mins)

Script:
check_writable.sh

echo "YES Writable" >> /tmp/test_file.txt


if [ $? == 0 ]
then
#File is writable
Return_value=1
else
#File is not writable
Return_value=0
fi

echo $Return_value



The value returned by above script will be examined by Trigger, and if '0' is returned, trigger will be turned ON to let administrator know that the file is no longer writable.

Now if the file is not writable, there may be several reasons, like "Disk Space Full" or "Permission Denied" etc. But that reason of not able to write to file is not displayed in zabbix.

Now suppose we make small modification in script and change to:



Script:
check_writable.sh

echo "YES Writable" >> /tmp/test_file.txt


if [ $? == 0 ]
then
echo File is writable
Return_value=1
else
echo "Disk Space Full"
Return_value=0
fi

echo $Return_value



The above script will also return some comments like "Disk Space Full".

Is there any way we can capture these comments and put in COMMENTS in triggers.

Please suggest.

Thanks & regards

Ashwani Jain

[troffasky]

But how to configure an ITEM to also capture comments returned by any particular script.

Why return '1' or '0'? Why not just return the comment?

[ashuji]

IF so

If we return complete comment, how will it benefit. How will we setup trigger to analyse the text comment captured take decision to turn ON.

[Calimero]

Return "OK" when everything is OK and write a trigger that checks that latest value is "OK" ?

[troffasky]

Surely the only comment the script will be returning is a comment you program into it, ergo, for any comment, you know what the condition is and can create a trigger accordingly.

Alternatively, you could use a Throw Map to convert the numeric value sent to Zabbix back to a string. Look at Config > General > Value Mapping for some examples.

[ashuji]

Example

I tried this, but i could not setup trigger to evaluate the text value stored in ITEM. What formula could be setup in trigger to parse certain strigs from text value and calculate is to decide where to turn on trigger:

For example, if value returned to ITEM is "no disk space left on /tmp" or "Permission denied" or "No such file or directory found"

What I wanted is that, trigger should decide ON/OFF by value '1' or '0' returned by script and it should put success/error comments returned by script into COMMENTs field of TRIGGER.

[Calimero]

One option is to have the script return "OK" on success and an error message when things go wrong.

{myhost:my_char_item.str("OK")}#1
==> trigger is ON if last value is different from "OK"

And use {ITEMVALUE} in your action/message.

Or as troffasky said create various return codes and use zabbix' mapping feature.

0 = OK
1 = disk full
2 = permission denied
3 = no such file
...

[ashuji]

Does not work

Hi

I created following script and ITEM but zabbix showing item "Not Supported":

[root@SANDBOX2 scripts]# cat /etc/zabbix/bin/check_file.sh
A="`cat /tmp/test.log`"

if [ $? == 0 ]
then
RET_VAL=OK
else
RET_VAL=$A
fi

echo $RET_VAL


[root@SANDBOX2 scripts]# zabbix_agent -t check_file
check_file [t|OK]

Item and Trigger configuration in the images attached with this thread. Item was configured but became unsupported, tried to create trigger as suggested but it failed to save. Kindly have a look and suggest solultion.

Regards

Ashwani jain

[trikke]

Hi Try:

....str(OK)}#1 -> No "

To get more info on your ERROR, just click the Red-ERROR "BOX"!

Greets
Patrick

[ashuji]

Whats problem with ITEM

Thank, I'll try this new formula in TRIGGER but whats problem with the ITEM, the ITEM i configured is shown 'not supported' in zabbix. If I check the KEY on monitored host using 'zabbix_agent -t check_file' it returns OK. Screen shot of config. of ITEM i had attached with the reply.

Please check the ITEM config and suggest why is it shown 'not supported' in zabbix ui.

Thanks & regards

Ashwani Jain

[trikke]

OK,

first to get a feeling what the Server will receive, try folowing command from the Server: "zabbix_get -s SANDBOX2 -k check_file" as this is the "command" the Server does against the agent ( Agent side seem ok as you checked with agent -t ...)
Then just change your item from not supported to aktiv.
Check your zabbix_server.log file for possible error messages, check your zabbix_agentd.log file on the agent for possible errors.
this should bring u further.
As a last thing set your agent to debug=4, restart agent and again check agent logfile for errors or whatever.

By the way, how did u embeded the script in the aganets conf??

Why don't u just use an item with: system.run[/etc/zabbix/bin/check_file.sh] and leave the Agent "virgin"?

Greets
Patrick

[ashuji]

Tried, strange behaviour

Hi,

First I checked the agent config on SANDBOX2:

[root@SANDBOX2 ~]# tail -n1 /etc/zabbix/zabbix_agent.conf
UserParameter=check_file,/etc/zabbix/bin/check_file.sh

Now check if the key is working:

[root@SANDBOX2 ~]# zabbix_agent -t check_file
check_file [t|OK]

Check the IP of this monitored host:

[root@SANDBOX2 ~]# ifconfig | grep 192
inet addr:192.168.90.243 Bcast:192.168.90.255 Mask:255.255.255.0


Now checked from Zabbix server:

[root@zabbix1 ~]# zabbix_get -s 192.168.90.243 -k check_file
ZBX_NOTSUPPORTED


See the strange behaviour, on monitored host if we check the key using "zabbix_agent -t <key" the key return desired result. But if we check the same key from Zabbix server using "zabbix_get" it says not supported.

Regards

Ashwani Jain

[trikke]

Hi,

please do set debug=4 at agent, restart agent and check logfile for error messages when trying "zabbix_get -s 192.168.90.243 -k check_file" this should give u a clue.
Mabybe EnableRemoteCommands=1 in agent conf???

Greets
Patrick

[ashuji]

Not working

Hi

I enabled remote commands in agent.conf of monitored host but still the problem is same:

Here below is the contents of agent.conf:

[root@SANDBOX2 ~]# cat /etc/zabbix/zabbix_agent.conf
# This is config file for zabbix_agent
# To get more information about ZABBIX,
# go http://www.zabbix.com

# IP address of ZABBIX server
# Connections from other hosts will be denied

# JSM: This IP will only work in staging for Site A layers
# JSM: Correct this if needed
Server=192.168.90.98
EnableRemoteCommands=1
# Spend no more than Timeout seconds on processing
# Must be between 1 and 30

Timeout=30

####### USER-DEFINED MONITORED PARAMETERS #######
#UserParameter=system.test,who|wc -l
### Change -u<username> and add -p<password> if required
UserParameter=mysql.ping,mysqladmin -uroot ping|grep alive|wc -l


Regards

Ashwani Jain

[ashuji]

Works

OK, this trigger formula is working in case ITEM type is Character or Log but not working if ITEM type is TEXT, is there any alternate for STR to be used with TEXT type ITEMs.

Thanks & regards

Ashwani Jain