How to configure metrics-server to monitor kubernetes cluster resources ?

-

For any virtualization or cloud platform, resource monitoring is a critical operational component. And its applicable for Kubernetes platform as well. As documented in Tools for Monitoring Resources, a lightweight, short-term, in-memory tool called metrics-server cab be used to collect the CPU & Memory utilization of nodes and pods in a kubernetes cluster.

The configuration of metrics-server is really simple and can be deployed easily on the kubernetes-master node. Refer the following steps to configure the metrics-server on an existing kubernetes cluster:


a. We have a 3 node cluster already deployed and ready for the configuration.

   
     

b. Login to the k8s-master node and get the components.yaml file from the latest release. While writing this document, the latest release is v0.4.2

    # wget  https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml   

c. Open the file and go to the containers argument section:

 

d. Include the following line as marked below and save the file:

     

e. Now the deployment file is ready for the deployment. Use the below command to deploy it:

  # kubectl apply -f  components.yaml

f. If anything will be available, it wont change and new components will be created:

     

g. Once deployment is complete, you can see the deployment, service and pods as mentioned below:

 

h. If you will check for the apiservices, you should be able to see a new entry there too which is running in the kube-system namespace:

     

Now it will take just few seconds to collect the nodes and pods resource utilization details. And you should be able to query the resource details using the following commands:

a. To get the node's resource utilization, use the below command:

     

b. To get the pod's resource utilization, use the below command:

     

    You can filter the namespace based resource utilization using specific flags as mentioned above.

c. To check how many containers are running in a pod, use the below command:

     

    Now as highlighted above, there is a pod in the kube-system namespace that's having two containers in it. If you want to check the resource utilization of both the containers in that pod, use the below command as shown:

     

    The command line tool is having some limitations and monitoring the resources beyond this out of scope at this point of time. That's why a better way to monitor the container level resource utilization is using Prometheus. Its a community driven opensource monitoring tool with much better monitoring capabilities. Refer the architecture documents to know more about it.

Comments

Post a Comment

Popular posts from this blog

VNC Configuration using Ansible in CentOS 7

-
1. Install epel repo on CentOS 7 system:   # yum install epel-release -y 2. Install ansible using yum:   # yum install ansible -y 3. Go to '/etc/ansible/roles/' directory and run the below command to create the skeleton directory structure:   # ansible-galaxy init vnc7 --offline   # tree vnc7          vnc7     ├── defaults     │   └── main.yml     ├── files     ├── handlers     │   └── main.yml     ├── meta     │   └── main.yml     ├── README.md     ├── tasks     │   └── main.yml     ├── tests     │   ├── inventory     │   └── test.yml     └── vars         └── main.yml 4. Create the service file to allow 'root' user to access the vncserver using port 5901.    In "/etc/ansible/roles/vnc7/files/" directory create a file with "vncserver@:1.service" name and add the below content:   [Unit]   Description=Remote desktop service (VNC)   After=syslog.target network.target   [Service]   Type=forking   # Clean any exis
Read more

How to build Ubuntu Server 20.04 LTS OVA with vAPP Properties ?

-
Image
This document will explain how to build an Ubuntu Server 20.04 LTS ova with vAPP properties enabled. Requirement: VM Deployment access required in vCenter environment. We have used the vCenter Server 6.7 and ESXi 6.5 while documented the below steps 1. Install a ubuntu server 20.04 lts vm with minimal cpu, ram and HDD(as needed). Make your own partition. 2. Use apt-get to upgrade all the packages along with the additional packages that required to install in the vm:      $ sudo apt-get update && apt-get upgrade -y 3. Make sure that 'open-vm-tools' and 'ifupdown' package is installed in the vm:       $ sudo apt-get install open-vm-tools  -y       $ sudo apt-get install ifupdown  -y 4. Take the console of the vm and stop, disable and mask the Network Manager service:       $ systemctl  stop  NetworkManager.service       $ systemctl  disable NetworkManager.service       $ systemctl  mask NetworkManager.service        5. Delete the Network Manager config file:      
Read more

[RHOSP] Red Hat Openstack 11 Deployment on Nested KVM Infrastructure

-
Image
This type of deployment is mainly helpful for POC or demo where all required opensatck components can be integrated to see how their functionality will work. I have a KVM host installed with RHEL 7.5 having the following resources: [ root@kvmhost ~ ]# free -h                  total      used      free          shared    buff/cache   available Mem:       70G       57G      339M        234M       12G          12G Swap:      4.0G      734M    3.3G [ root@kvmhost ~ ]# cat /proc/cpuinfo | egrep processor processor       : 0 processor       : 1 processor       : 2 processor       : 3 processor       : 4 processor       : 5 processor       : 6 processor       : 7 processor       : 8 processor       : 9 processor       : 10 processor       : 11 processor       : 12 processor       : 13 processor       : 14 processor       : 15 [ root@kvmhost ~ ]# fdisk -l /dev/sda Disk /dev/sda: 898.3 GB, 898319253504 bytes, 1754529792 sectors
Read more