vSphere with Tanzu using NSX-T - Part34 - CPU and Memory utilization of a supervisor cluster

vSphere with Tanzu is a Kubernetes-based platform for deploying and managing containerized applications. As with any cloud-native platform, it's essential to monitor the performance and utilization of the underlying infrastructure to ensure optimal resource allocation and avoid any potential issues. In this blog post, we'll explore a Python script that can be used to check the CPU and memory allocation/ usage of a WCP Supervisor cluster.

You can access the Python script from my GitHub repository: https://github.com/vineethac/VMware/tree/main/vSphere_with_Tanzu/wcp_cluster_util

Sample screenshot of the output

The script uses the Kubernetes Python client library (kubernetes) to connect to the Supervisor cluster using the admin kubeconfig and retrieve information about the nodes and their resource utilization. The script then calculates the average CPU and memory utilization across all nodes and prints the results to the console.

Note: In my case instead of running it as a script every time, I made it an executable plugin and copied it to the system executable path. I placed it in $HOME/.krew/bin in my laptop.

Hope it was useful. Cheers!

Working with Kubernetes using Python - Part 03 - Get nodes

Following code snipet uses kubeconfig python module to switch context and Python client for the kubernetes API to get cluster node details. It takes the default kubeconfig file, and switch to the required context, and get node info of the respective cluster. 

kubectl commands: 

kubectl config get-contexts
kubectl config current-context
kubectl config use-context <context_name>
kubectl get nodes -o json

Code: 

Reference:

https://kubeconfig-python.readthedocs.io/en/latest/
https://github.com/kubernetes-client/python

Hope it was useful. Cheers!

Working with Cisco Nexus 9K switches using PowerShell

In this article, I will explain briefly about how to work with Cisco NX-API CLI through PowerShell. Before getting into the steps and sample PowerShell code, lets first familiarize with NX-API Developer Sandbox. You can access the sandbox by entering the management IP of your Cisco switch in a web browser. Provide user name and password. Once successfully logged in, you will get a page as shown below. The developer sandbox will convert the normal CLI commands into JSON request and will also provide result/ response in JSON format.

NX-API Developer Sandbox

In the above screenshot, I am using "show hostname" command. The message format is set to JSON and command type is set to cli_show to get a response in JSON. Once done, hit POST. You can see the corresponding request and response in JSON format.

Now, let's try to do the same using PowerShell.

#Step1:

<# 

To fix the connection issues <The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.>

#> 

add-type @"

    using System.Net;

    using System.Security.Cryptography.X509Certificates;

    public class TrustAllCertsPolicy : ICertificatePolicy {

    public bool CheckValidationResult(

        ServicePoint srvPoint, X509Certificate certificate,

        WebRequest request, int certificateProblem) {

        return true;

        }

    }

"@

[System.Net.ServicePointManager]::CertificatePolicy = New-Object TrustAllCertsPolicy

[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.SecurityProtocolType]::Tls12 -bor [System.Net.SecurityProtocolType]::Tls11

#Step2:

$creds = Get-Credential

#Step3:

$request = @'

{

    "ins_api": {

          "version": "1.0",

          "type": "cli_show",

          "chunk": "0",

          "sid": "1",

          "input": "show hostname",

          "output_format": "json"

    }

}

'@

#Step4:

$result = Invoke-RestMethod -Uri "http://<IP of switch>/ins" -Method post -Credential $creds -ContentType "application/json" -Body $request

Output:

Hope it was useful. Cheers!

Reference:

https://inbound.kelsercorp.com/blog/cisco-nexus-9000-automation

Working with iDRAC9 Redfish API using PowerShell - Part 2

In this article I will explain briefly about the JSON response from iDRAC and how you can navigate through the Redfish API tree structure to get all the required information. Now, lets have a look at the URIs. 

Query the computer system collection:

$result1 = Invoke-RestMethod -Uri "https://$($idrac_ip)/redfish/v1/Systems" -Credential $Credentials -Method Get -UseBasicParsing -ContentType 'application/json'

Response: 

You can see one member with URI /redfish/v1/Systems/System.Embedded.1

Below is a sample screen shot of JSON output when you try to query the above listed member system. 

You can get some of the basic information straight away from the above JSON response. And these are organized in hierarchy where you can drill down to each object and get the required details. Below diagram shows basic iDRAC Redfish API tree structure.

Example: You can get details/ health status of  storage controller as shown below.

Query:

$result2 = Invoke-RestMethod -Uri "https://$($idrac_ip)/redfish/v1/Systems/System.Embedded.1/Storage /Controllers/NonRAID.Integrated.1-1" -Credential $Credentials -Method Get -UseBasicParsing -ContentType 'application/json'

Response:

Hope it was useful. Cheers!

References:

Working with iDRAC9 Redfish API using PowerShell - Part 1

iDRAC9 Redfish API reference guide

github.com/dell/iDRAC-Redfish-Scripting

Working with iDRAC9 Redfish API using PowerShell - Part 1

Redfish is a industry standard protocol and specification defined by Distributed Management Task Force (DMTF) for performing systems/ IT infrastructure management actions using RESTful methodology. It is a next generation systems management interface standard which is simple, secure, scalable. Redfish uses JSON data format and transports payload over HTTPS. Initial releases of Redfish focused primarily on systems management and was targeted to be a replacement for IPMI over LAN protocol. Now the capabilities have been extended over the past few years providing a rich set of features and support for network, memory, storage devices etc. Over time the scope of Redfish is being expanded to fit more use cases as the forum is working with several partner organizations. Promoters of this standard include several companies like Broadcom, Cisco, Dell, HP, VMware, Intel, Microsoft etc.

Now, lets have a look at how to connect to iDRAC Redfish API using PowerShell. Redfish provides two authentication methods. Basic authentication and Session-based authentication. Here I will explain basic authentication using username and password for each Redfish API request to iDRAC.

#To fix the connection issues to iDRAC REST API

add-type @"

    using System.Net;

    using System.Security.Cryptography.X509Certificates;

    public class TrustAllCertsPolicy : ICertificatePolicy {

    public bool CheckValidationResult(

        ServicePoint srvPoint, X509Certificate certificate,

        WebRequest request, int certificateProblem) {

        return true;

        }

    }

"@

[System.Net.ServicePointManager]::CertificatePolicy = New-Object TrustAllCertsPolicy

[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.SecurityProtocolType]::Tls12 -bor [System.Net.SecurityProtocolType]::Tls11

#Get iDRAC creds

$Credentials = Get-Credential -Message "Enter iDRAC Creds"

#URI to get basic system info

$u1 = "https://192.168.10.11/redfish/v1/Systems/System.Embedded.1"

#Using Invoke-RestMethod

$result1 = Invoke-RestMethod -Uri $u1 -Credential $Credentials -Method Get -UseBasicParsing -ContentType 'application/json' -Headers @{"Accept"="application/json"}

Output:

Hope it was useful. Cheers!

References:
iDRAC9 Redfish API reference guide
github.com/dell/iDRAC-Redfish-Scripting