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https://github.com/itaysk/kubectl-neat

Clean up Kubernetes yaml and json output to make it readable
https://github.com/itaysk/kubectl-neat

hacktoberfest kubectl-plugin kubernetes

Last synced: 3 days ago
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Clean up Kubernetes yaml and json output to make it readable

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README 

        
# kubectl-neat



Remove clutter from Kubernetes manifests to make them more readable.



## Demo



Here is a result of a `kubectl get pod -o yaml` for a simple Pod. The lines marked in red are considered redundant and will be removed from the output by kubectl-neat.



![demo](./demo.png)



## Why



When you create a Kubernetes resource, let's say a Pod, Kubernetes adds a whole bunch of internal system information to the yaml or json that you originally authored. This includes:



- Metadata such as creation timestamp, or some internal IDs

- Fill in for missing attributes with default values

- Additional system attributes created by admission controllers, such as service account token

- Status information



If you try to `kubectl get` resources you have created, they will no longer look like what you originally authored, and will be unreadably verbose.   

`kubectl-neat` cleans up that redundant information for you.



## Installation



```bash

kubectl krew install neat

```



or just download the binary if you prefer.



When used as a kubectl plugin the command is `kubectl neat`, and when used as a standalone executable it's `kubectl-neat`.



## Usage



There are two modes of operation that specify where to get the input document from: a local file or from  Kubernetes.



### Local - file or Stdin



This is the default mode if you run just `kubectl neat`. This command accepts an optional flag `-f/--file` which specifies the file to neat. It can be a path to a local file, or `-` to read the file from stdin. If omitted, it will default to `-`. The file must be a yaml or json file and a valid Kubernetes resource.



There's another optional optional flag, `-o/--output` which specifies the format for the output. If omitted it will default to the same format of the input (auto-detected).



Examples:

```bash

kubectl get pod mypod -o yaml | kubectl neat



kubectl get pod mypod -oyaml | kubectl neat -o json



kubectl neat -f - <./my-pod.json



kubectl neat -f ./my-pod.json



kubectl neat -f ./my-pod.json --output yaml

```



### Kubernetes - kubectl get wrapper



This mode is invoked by calling the `get` subcommand, i.e `kubectl neat get ...`. It is a convenience to run `kubectl get` and then `kubectl neat` the output in a single command. It accepts any argument that `kubectl get` accepts and passes those arguments as is to `kubectl get`. Since it executes `kubectl`, it need to be able to find it in the path.



Examples:

```bash

kubectl neat get -- pod mypod -oyaml

kubectl neat get -- svc -n default myservice --output json

```



# How it works



Besides general tidying for status, metadata, and empty fields, kubectl-neat primarily looks for two types of things: default values inserted by Kubernetes' object model, and common mutating controllers.



## Kubernetes object model defaults



For de-defaulting Kubernetes' object model, we invoke the same code that Kubernetes would have, and see what default values were assigned. If these observed values look like the ones we have in the incoming spec, we conclude they are default. If they weren't, and the user manually set a field to it's default value, it's not a bad thing to remove it anyway.



## Common mutating controllers



Here are the [recommended](https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#what-does-each-admission-controller-do) admission controllers, and their relation to kubectl-neat:



controller | description | neat

---|---|---

NamespaceLifecycle | rejects operations on resources in namespaces being deleted | ignore

LimitRanger | set default values for resource requests and limits | ignore

ServiceAccount | set default service account and assign token | Remove `default-token-*` volumes. Remove deprecated `spec.serviceAccount`

TaintNodesByCondition | automatically taint a node based on node conditions | TODO

Priority | validate priority class and add it's value | ignore

DefaultTolerationSeconds | configure pods to temporarily tolarate notready and unreachable taints | TODO

DefaultStorageClass | validate and set default storage class for new pvc | ignore

StorageObjectInUseProtection | prevent deletion of pvc/pv in use by adding a finalizer | ignore

PersistentVolumeClaimResize | enforce pvc resizing only for enabled storage classes | ignore

MutatingAdmissionWebhook | implement the mutating webhook feature | ignore

ValidatingAdmissionWebhook | implement the validating webhook feature | ignore

RuntimeClass | add pod overhead according to runtime class | TODO

ResourceQuota | implement the resource qouta feature | ignore

Kubernetes Scheduler | assign pods to nodes | Remove `spec.nodeName`