I'm using monit to monitor some services. However, I want to get an email which includes the output from top when this happens. Is there some way to get this information?
Don't know if you can get it from the mail-format (which would be pretty nice) but they have the following example in the monit wiki:
check file myfile with path /tmp/foo.bar if changed timestamp then
exec "/bin/bash -c 'top -bn1 | mail -s top admin#foo.bar'"
Related
What permissions do I need to assign to a software, which will monitor my RabbitMQ server? The software agent should monitor most of the metrics explained and recommended in this document.
I think I have to create a user, e.g. monitoring and then give this user access to all virtual hosts which contain ressources that should be monitored.
I think when creating the user I have to assign it the tag monitoring which is a predefined tag.
What I do not understand is, what RegEx I need to assign to configure, write and read. The documentation contains a table with the permissions on ressources.
I think a monitoring software should not be able to create or delete ressources (configure permission) nor should it be able to ADD messages to a queue or READ and ACK messages from a queue. But for example it should be able to read the number of messages waiting in a queue to alert if a queue has a number of growing messages which are not retrieved.
Could anybody explain, what permissions and settings are required for such a monitoring user?
Here is a quick guide from the beginning to the end while you are setting up RabbitMQ queues monitoring.
1) Create an account:
rabbitmqctl add_user monitoring password
2) Add monitoring tag (you can read more about RabbitMQ tags here https://www.rabbitmq.com/management.html)
rabbitmqctl set_user_tags monitoring monitoring
3) Now get the names of your virtual hosts:
rabbitmqctl list_vhosts
4) Add permission for monitoring user to virtual host:
rabbitmqctl set_permissions -p Some_Virtual_Host monitoring "" "" ""
5) Check if access is granted successfully:
curl -s -u monitoring:password http://localhost:15672/api/queues | jq
Look at the "messages" parameter
Optional) You can publish a fake message from the command line:
rabbitmqadmin publish --vhost=Some_Virtual_Host exchange=some_exchange routing_key=outgoing_routing_key payload="hello world"
Look at the "messages" again!
Tip: make sure to enable rabbitmq_management plugin in your RabbitMQ build to be able to execute these queries.
Figured that out myself with some testing. If someone is interested:
Create an account with monitoring tag
Add that account to EVERY vhost that should be monitored and add empty strings ("") to configure, write and read permissions.
With a nice bash script you can then for example get the numbers of messages in every queue:
curl -u username:password \
--silent \
http://<ServerOrIP>:15672/api/queues/<vhostname> | jq '.[] | .name, .messages'
What is jq? An explanation is missing from the answers provided above.
The jq command is in the EPEL repository.
https://www.cyberithub.com/how-to-install-jq-json-processor-on-rhel-centos-7-8/
# yum --enablerepo=epel install jq
can anyone point me in the right direction?
I want to send the following webpage request using a cron job with raspberry pi,
http://10.0.1.224/socket1On
thanks
Install curl using aptitude install curl, then crontab -e and...
0 * * * * curl http://10.0.1.224/socket1On >/dev/null
(This runs once on each full hour - adjust as necessary of course.)
This throws away the answer; if you need it, you can save it to some file, or course. Errors will be mailed to whatever mail account you let your mails get forwarded to, by cron.
My java program uses ssh/sftp for transferring files into linux machines (obviously...), and my library for doing so is JSch (though it's not to blame).
Now, some of these linux machines, have shell login startup scripts, which tragically causes the ssh/sftp connection to fail, with the following message:
Received message too long 1349281116
After briefly reading about it, it's clearly a known ssh design issue (not a bug - see here). And all suggested solutions are on ssh-server side (i.e. disable scripts which output messages during shell login).
My question - is there on option to avoid this issue on client side?
Check your .bashrc and .bash_profile on the server, remove anything that can echo. For now, comment the lines out.
Try again. You should not be seeing this message again.
put following into the top of file ~/.bashrc on username of id on remote machine
# If not running interactively, don't do anything just return early from .bashrc
[[ $- == *i* ]] || return
this will just exit early from the .bashrc instead of sourcing entire file which you do not want when performing a scp or sftp onto that target remote machine ... depending on shell of that remote username, make this edit on ~/.bashrc
or ~/.bash_profile or ~/.profile or similar
I got that error too, during and sftp get call in a bash script.
And according to the TO's error message, which was similar to mine, it looks like the -B option of the sftp command was set. Although a buffer size of 1349281116 bytes is "a bit" too high.
In my case I also did set the buffer size explicitly (with "good intentions"), which cause the same error message, followed by my set value.
Removing the forced value and letting sftp run with the default of 32K solved the problem to me.
-B buffer_size
Specify the size of the buffer that sftp uses when transferring
files. Larger buffers require fewer round trips at the cost of
higher memory consumption. The default is 32768 bytes.
In case it confirms to be the same issue, that whould suite as client side solution.
NOTE: I had to fix .bashrc output on the remote hosts, not the host that's issuing the scp or sftp command.
Here's a quick-n'-dirty solution, but it seems to work - also on binary files. All credits goes to uvgroovy.
Given file 'some-file.txt', just do:
cat some-file.txt | ssh root:1.1.1.1 /bin/bash -c "cat > /root/some-new-file.txt"
Still, if anyone know a sftp/scp built-in way to do so on client side, it'll be great.
I want to run a command on Zabbix agents:
Some simple unix commands, to obtain our reporting data.
When there is some processing required on the agent side.
There seem to be a variety approaches being talked about. So how to execute such commands on a Zabbix agent?
Run commands from the server directly from a new item.
First, set: EnableRemoteCommands=1 in the agent conf file (for all of your agents). To enable this feature.
Create a new item. A field on the "new item" page says 'key'. Enter:
system.run[command]
As the 'key' string. Where command is the command you want to be downloaded and run on the agent. Here is an example:
system.run[sysctl dev.cpu.0.temperature | cut -d ' ' -f 2 | tr -d C]
Perhaps you need to run something substantially more complex that is too long to fit in there? Then you will need to make a custom script. Put your custom scripts on a local webserver, or somewhere on the web.
Then you might set the item's key to:
system.run[ command -v script && script || wget script_url -O /path/to/script && script]
To fetch and download the missing script to the agent the first time it's executed. However that is a rather crude hack. Not very elegant.
A better way is to go to "Administration" --> "Scripts" in the menu. From there, you can create a new script to use in an item which may be configured to run on any of your agents.
Make a special custom item to re-run your script periodically (like a cron job). The job of the special script item is to update the agent with a collection of your other needed custom scripts.
Of course you could just write all of your custom scripts directly into zabbix's MYSQL database. And it is very tempting to do that. But be aware that then they'd be lost and vulnerable if your zabbix database ever gets fried or corrupted / lost. Zabbix databases always have a habit of growing large, unwieldy and out-of-control. So don't do that. Storing them separately somewhere else and under version control (git or subversion).
Once that's all sorted, we can finally go ahead and create further custom items to run your custom scripts. Again using:
system.run[script]
as the item's key just as before. Where 'script' is the command (plus any arguments), to execute your custom script locally on the agent.
Define the user parameter at the client (where zabbix agent is
located) at /etc/zabbix/zabbix_agentd.conf
The key should be
unique. I am using lsof as an example: UserParameter=open_file,lsof | wc -l
Restart the agent: service zabbix-agent restart
Test if the key is working using zabbix_get utility. To do that from the zabbix server, invoke the following: /usr/local/bin/zabbix_get -s <HOST/IP of the zabbix agent> -k open_file (It should return a number in this case)
Create an item with the key at the zabbix server at the template
level (the return type should be correctly defined, otherwise zabbix
will not accept it):
Type: Zabbix Agent (Active)
Key: open_file
Type of Information: Numeric (unsigned)
Data Type: decimal
You may create a graph using the item to monitor the value at
regular interval.
Here is the official documentation.
I am launching a launchAgent from a post install script using the following command:
su -l $LOGGED_IN_USER -c "/bin/launchctl load /Library/LaunchAgents/com.myApp.mac.agent.plist"
The agent displays a status item (NSStatusItem) with a couple of menu options. One of them has a settings option. Clicking this will open an NSWindow, with few NSTextFields. At times, though this window is the top most, whatever I type goes to the underlying app. I am unable to type anything into the text field. Whenever this happens, I notice the following log in the console:
WindowServer[97]: [cps/setfront] Failed setting the front application to MyApp, psn 0x0-0xb20b2, securitySessionID=0x186c5, err=-600
This is not a consistent behaviour. Any idea why this log comes? And is there any work around for this? Is it ok to launch the agent using su -l?
I don't know exactly why you're getting that error and behavior. I recommend reading Technical Note TN2083: Daemons and Agents. It explains in detail the various facets of the execution context of a process and how that affects what a process can do. That includes whether or not a process can connect to the Window Server.
For what it's worth, error -600 is procNotFound, whose description is "no eligible process with specified descriptor". It seems that the Window Server is not able to find a process with the given process serial number (PSN) in the given security session.
I would not use -l in your sudo command. A user's login scripts can do all sorts of crazy things and you don't those done by your installer. However, I don't believe that's related to the main problem.