Is there a possibility using the command --alarm-action 'log: //' to run any script or create a VM instances on OpenStack, for example:
Can I do something like this
$ ceilometer alarm-threshold-create --name cpu_high/\ --description 'instance running hot' --meter-name cpu_util --threshold 70.0 --comparison-operator gt --statistic avg --period 600 --evaluation-periods 3 --alarm-action './script.sh' --query resource_id=INSTANCE_ID
where --alarm-action './script.sh' launches script.sh
It's not possible for a Ceilometer action to run a script.
The OpenStack APIs have generally been designed under the assumption that the person running the client commands (a) is running them remotely, rather than on the servers themselves, and (b) is not an administrator of the system. In particular (b) means that permitting you to run arbitrary scripts on a server would be a terrible security problem, because you would first need a way to get a script installed on the server and then there would need to be a way to prevent you from trying to run, say, /sbin/reboot.
For this reason, the ceilometer action needs to be URL. You could set up a simple web server that would receive the signal from ceilometer and execute a script in response.
If you deploy resources using Heat, you can set up autoscaling groups and have ceilometer alarms trigger an autoscaling action (creating new servers or removing servers, for example).
Related
I would like to know (and retrieve via REST API) the uptime of individual VMs running in OpenStack.
I was quite surprised that OpenStack web UI has a colon called "Uptime" but it actually show time since the VM was created. If i stop the VM, the UI shows Status=Shutoff, Power State=Shutdown, but the Uptime is still being incremented...
Is there a "real" uptime (I mean for a machine that is UP)?
Can I retrieve it somehow via the OpenStack's REST API?
I saw the comment at How can I get VM instance running time in openstack via python API? but the page with the extension mentioned there does not exists and it looks to me that this extension will not be available in all OpenStack environment. I would like to have some standard way to retrieve the uptime.
Thanks.
(Version Havana)
I haven't seen any documentation saying this is the reason, but the nova-scheduler doesn't differentiate between a running and powered off instance. So your cloud can't be over-allocated or leave an instance in a position that would be unable to be powered on. I would like to see a metric of actual system runtime as well, but at the moment the only way to gather that would be through ceilometer or via Rackspaces StackTach
We have a production environment (cluster) where there are two physical servers and 3 (three) plone/zope instances running inside each one.
We scheduled a job (with apscheduler) that needs to run only in a unique instance, but is executing by all 6 (six) instances.
To solve this, I think I need to verify if the job is running in the server1 and if it is a instance that listens on a specific port.
So, how to get programmaticly informations about a zope/plone instance?
I have always used the os:cmd/1 method to call operating system routines. Now, i know that erlang has an ssh application. I would like to know how i can use this module to ssh into a SOLARIS server, run a command and collect the reply. I believe that such an operation would be handled asynchronously. I need an example using the ssh application built into Erlang doing this:
Now, at times we setup SSH KEYS between servers to prevent password prompt especially if one is using a script to execute tasks on remote servers. i am intending to write many Erlang programs or escripts that will interact with many remote servers within our environment. i need a complete example and explanation on how ssh with and/or without password prompt can be handled using erlang ssh application. NOTE: In the screen shot above, the two servers had SSH KEYS set up and so there is no password prompt when ssh is initiated from any of the two.
The correct erlang native API to achieve this is not ssh, which only implements a user-interactive shell for ssh, but instead use ssh_connection. Take a look at ssh_connection:exec/4
To be more complete, use ssh:connect to establish a connection and then using the handler returned from it to connect with ssh_connection:exec/4
I didn't try it myself and can't provide a complete example but the documentation seems to be a good starting point.
How can I configure splunk with log files residing on remote unix servers?
Normally I log into putty to a linux server, from there I ssh into another company server and I navigate through directories and perform my operations mainly as cat, zcat etc., with grep filters. Ex:
login to example_server with putty
ssh to ssh_server
cd to req dir
perform cat etc.,
ssh_server will not directly allow to be logged in from putty, I have to first login to example_server and then to ssh_server.
How can I configure these log files to be used by splunk to search for a string, similarly to how I use grep. I've installed splunk on my laptop, and by clicking add data > files and dir > add new it shows full path to the data field, what path should I fill it with?
The easiest answer is to install the Splunk Universal Forwarder (UF) on the remote Linux system. The UF is free and requires no license.
For more info - http://docs.splunk.com/Documentation/Splunk/latest/Data/Usingforwardingagents
In case it is not possible to install any new binary on the monitored server (like in my case) you should evaluate other options:
using the get log data from script option in splunk and creating a script looking like :
ssh user#10.10.10.10 cat /var/logs/logfile.log
warning: it will blow your index if you have a short polling interval and big logs, as each log event is registered every time you poll the file.
using a cron job runnig rsync to mirror the logs on the splunk server localy:
the job would look like this
/usr/bin/rsync -az user#10.10.10.10:/var/logs/ /var/remoteLogs/
In this case every added line will only generate a single log event i splunk
for both solutions installed SSH keys are mandatory
Ubuntu 10.10 64bit athalon, gnome
My basic scenario is I'm connecting to a VPN service (via newtworkmanager pptp protocol) and I'm transferring private data (hence VPN). The service goes down intermittantly and that's alright, probably due to my ISP/OS/VPN. What is not good is that my applications will then continue to transmit data via the eth0 default route and thats not cool. After some looking around I'm suspecting the best way to deal with this is to post scripts into /etc/NetworkManager/dispatcher.d. In short, the networkmanager service will execute scripts in this directory (and pass arguments to the scripts) when anything about the network changes.
My problem is that I can't get any of my scripts to execute. They all have, per the manpage, 0755 permissions and owned by root, but when I change the network state by unplugging ethernet cable, my scripts don't execute. I can execute them from the command line, but not automatically via the dispatcher....
an example script:
#!/bin/sh -e
exec /usr/bin/wmctrl -c qBittorrent
exit 0
This script is intentionally simple for testing purposes..
I can post whatever else would be helpful.
i'm using the syntax killall -9 any_application_name_here and that's working just fine. I imagine the script didn't have access to the binary wmctrl. I think that bash interpreter in this case will only execute bash binaries.
So, in a nutshell, if you want to control your VPN traffic based on network events, one way is to post scripts to /etc/NetworkManager/dispatcher.d and use binaries that are in bash's default path.