K
Q

Is there any API or go programming logic to get capacity of node in a kubernetes cluster?

3/6/2020

Using kubectl describe nodes, i am able to get the capacity of resources(memory,cpu) of a node. I want to get the same via go client or kube API (if available). Can anyone help me out? i am using minikube version: v1.7.2 kubectl version : Client : GitVersion:"v1.16.3" Server : GitVersion:"v1.16.2" I am using metric-server to access the kubernetes resource. Expected result: Capacity of resources should be accessible through go program or kube API

-- Pooja Sekaran
cluster-computing
kubectl
kubernetes
metrics
minikube

Similar Questions

How to configure NGINX to proxy API calls to backend deployed on Kubernetes?
Kubernetes Run multiple python script in Same Pod
Adding --record=true on a deployment file - Kubernetes
Kubernetes Host IP For Vault Authentication with Kubernetes Engine

2 Answers

3/6/2020

Kubernetes Client libraries are the ones you need to look at https://kubernetes.io/docs/reference/using-api/client-libraries/#officially-supported-kubernetes-client-libraries

The following client libraries are officially maintained by Kubernetes SIG API Machinery.

Language    Client Library
Go          github.com/kubernetes/client-go/    
Python      github.com/kubernetes-client/python/
Java        github.com/kubernetes-client/java   
dotnet      github.com/kubernetes-client/csharp 
JavaScript  github.com/kubernetes-client/javascript 
Haskell     github.com/kubernetes-client/haskell    


Community-maintained client libraries
The following Kubernetes API client libraries are provided and maintained by their authors, not the Kubernetes team.

Language                Client Library
Clojure                 github.com/yanatan16/clj-kubernetes-api
Go                      github.com/ericchiang/k8s
Java (OSGi)             bitbucket.org/amdatulabs/amdatu-kubernetes
Java (Fabric8, OSGi)    github.com/fabric8io/kubernetes-client
Lisp                    github.com/brendandburns/cl-k8s
Lisp                    github.com/xh4/cube
Node.js (TypeScript)    github.com/Goyoo/node-k8s-client
Node.js                 github.com/tenxcloud/node-kubernetes-client
Node.js                 github.com/godaddy/kubernetes-client
Node.js                 github.com/ajpauwels/easy-k8s
Perl                    metacpan.org/pod/Net::Kubernetes
PHP                     github.com/maclof/kubernetes-client
PHP                     github.com/allansun/kubernetes-php-client
PHP                     github.com/travisghansen/kubernetes-client-php
Python                  github.com/eldarion-gondor/pykube
Python                  github.com/mnubo/kubernetes-py
Python                  github.com/tomplus/kubernetes_asyncio
Ruby                    github.com/Ch00k/kuber
Ruby                    github.com/abonas/kubeclient
Ruby                    github.com/kontena/k8s-client
Rust                    github.com/clux/kube-rs
Rust                    github.com/ynqa/kubernetes-rust
Scala                   github.com/doriordan/skuber
dotNet                  github.com/tonnyeremin/kubernetes_gen
DotNet (RestSharp)      github.com/masroorhasan/Kubernetes.DotNet
Elixir                  github.com/obmarg/kazan
Elixir                  github.com/coryodaniel/k8s
Haskell                 github.com/kubernetes-client/haskell
-- Tummala Dhanvi
Source: StackOverflow
3/6/2020

There isn't any API call you could use to get kubectl describe nodes this is because this command is generating all the output.

Kubectl retrieves all relevant pods (every pod that isn't failed or succeeded) on a node and sums up all their resource definitions.

You can look into the code and find the function responsible for generating information about node here.

Same for collecting all requests and limits for pods, function is available here and it's called getPodsTotalRequestsAndLimits

Lastly the function what puts all that together can be seen here.

There is a really nice article about Kubernetes API: Allocatable Node Resources? The author is doing exactly what you are asking for but using Python.

-- Crou
Source: StackOverflow