Introduction
Ceilometer is used to collect measurements of different utilizations (memory, CPU, Hard, ….) from OpenStack components. It is designed originally for billing. It is not a complete monitoring solution for metering because it does not allow service/application level monitoring and it ignores the detailed metrics of the guest system.
Rackspace’ cloud which is Openstack based cloud solution has its own monitoring service which allow the tenants to keep their measured data whether standard (e.g. CPU, Memory, …) or custom (application/service specific metrics) on the cloud and create the notification plans they want.
In this article, i will show you how to automate the setup of Rackspace monitoring agent on the virtual machine. So when your auto scale policy is triggered, you will have a new server with the monitoring agent installed and connected to the cloud. I have Centos-7 for my virtual machine which i will use later to create the image. The image will be used by the auto scaling service to create new servers. You need to have an account with Rackspace cloud provider.
Rackspace Monitoring Agent Installation on Centos 7
Install the package signing key
# curl https://monitoring.api.rackspacecloud.com/pki/agent/centos-7.asc > /tmp/signing-key.asc
# rpm –import /tmp/signing-key.asc
Add the agent repository to yum
- Create and edit the file “/etc/yum.repos.d/rackspace-cloud-monitoring.repo”
# vi /etc/yum.repos.d/rackspace-cloud-monitoring.repo
- Add the configuration of the repository. In my case i have centos7:
[rackspace]
name=Rackspace Monitoring
baseurl=http://stable.packages.cloudmonitoring.rackspace.com/centos-7-x86_64
enabled=1
Install the agent
# yum install rackspace-monitoring-agent
Now we have the agent installed on the current virtual machine.
Create oneshot systemd or init service for the agent setup
The setup process is needed to configure the monitoring agent for the specific server, verifies the connectivity with the cloud, and association with the monitoring entity of the server. The script that you will write does the setup of the agent as following:
# rackspace-monitoring-agent –setup -U username -K apikey
Replace the username and apikey with yours. You can take the API key from your account settings when you access the web control panel.
The script needs also to start the agent if it is not started:
# systemctl start rackspace-monitoring-agent
As this service will be executed on boot, you need to be sure that it is executed only when the server is created (only once). So you need to write a check which examine if rackspace-monitoring-agent service is started or not. If it is started so do NOT set it up again.
Clean after preparation
If you test the setup on the current virtual machine, you need to clean it up so the new servers created from the image will not have the old configuration of the server that is used to create the image. Simply stop the service, uninstall the agent. Then install the agent again without the setup. If you want to have your image independent on the account information you need to make the installation and the setup of the monitoring agent as YAML template executed by the cloud. See the last link in the section “More Information” further down.
Server-Side Agent Configuration YAML File
For example a YAML configuration file that creates a CPU check with alarm. Bind the check with the auto scaling policy notification plans. Create the file “cpu.yaml” in the folder “/etc/rackspace-monitoring-agent.conf.d” with this content:
type : agent.cpu
label: CPU
period: 60
timeout: 10
alarms:
cpu-usage-up:
label: CPU Usage Up
notification_plan_id: scale-up-notification-plan-id-here
criteria: |
if (metric[‘usage_average’]> 80){
return new AlarmStatus(CRITICAL);
}
cpu-usage-down:
label: CPU Usage Down
notification_plan_id: scale-down-notification-plan-id-here
criteria: |
if (metric[‘usage_average’]< 50){
return new AlarmStatus(WARNING);
}
To get the ids of your created notifications, execute this:
# curl -s -X GET https://monitoring.api.rackspacecloud.com/v1.0/$tenantID/notifications -H “X-Auth-Token: $token” -H “Accept: application/json” | python -m json.tool
Create a new image
Now you can go to the web control panel and create a new image that will be used in auto scaling process.
Next
The next article will be about how to send custom measured data (custom metrics) to your cloud using the monitoring agent. this is called creating custom plugin. I will show you how to create a custom check.
More Information
- Rackspace Monitoring Agent Installation
- Server-Side Configuration YAML Files
- YAML Template To Install and Configure Rackspace Monitoring Agent In Autoscale Context.