powershell profile functions for working with kubernetes

k8s.ps1

# for all of this to work, you need FZF! https://github.com/junegunn/fzf

New-Alias -Name k -Value kubectl -force

kubectl completion powershell | Out-Null

# enable colours
$ESC=[char]27
$RED="$ESC[31m"
$GREEN="$ESC[32m"
$YELLOW="$ESC[33m"
$BLUE="$ESC[34m"
$MAGENTA="$ESC[35m"
$CYAN="$ESC[36m"
$END="$ESC[0m"

# enable special text formating
$BOLD="$ESC[1m"
$LOW="$ESC[2m"
$UNDERLINE="$ESC[4m"
$INVERT="$ESC[7m"
$PASSWORD="$ESC[8m"
$BLINK="$ESC[5m"
$NORMAL="$ESC[0m"

function base64 {
    param (
        [Parameter(Mandatory = $false)]
        [switch]$d,
        [Parameter(Mandatory = $false)]
        [string]$value,
        [Parameter(ValueFromPipeline=$true)]
        [string[]]$in
    )

    $value = $in ? $in : $value

    if (Test-Path -Path $value -PathType Leaf) {
        $value = Get-Content $value
    }

    switch ($d) {
        $true { 
            return [System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($value))
        } 
        Default {
            return [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($value))
        }
    }
}

function Get-KubePS1 {
    if ($env:KUBEPS1 -eq 1) {
        if (!$env:KUBECONTEXT -or !$env:KUBENS) { 
            $env:KUBECONTEXT = kubectl config current-context
            $env:KUBENS = kubectl config view --minify -o jsonpath='{..namespace}'
        }
        return '(' + $BLUE + [char]0x2388 + $RED + " $env:KUBECONTEXT" + $END + ':' + $CYAN + "$env:KUBENS" + $END + ') '
    } else { 
        return ''
    }
}

# turn kubeps1 prompt on or off
function kps {
    if ($env:KUBEPS1 -eq 1) {
        $env:KUBEPS1 = 0
    } else {
        $env:KUBEPS1 = 1
    }
}
$env:KUBEPS1 = 1

# load all kubeconfigs into KUBECONFIG env var, so I don't have to maintain one big kubeconfig file
function Get-kubeconfigs {
    # you need to create this dir and put your kubeconfig files into it
    $kubeConfigDir = "$HOME/.kube/configs"
    $env:KUBECONFIG = ""
    foreach ($config in (Get-ChildItem $kubeConfigDir)) {
        $env:KUBECONFIG += ";$config"
    }
}
Get-kubeconfigs

# this is my short version of the official ktx 
# the official ktx doesn't support multiple kubeconfigs
# in the KUBECONFIG env var - hence I've created my own
function ktx {
    $context = kubectl config get-contexts -o name | fzf
    kubectl config use-context $context
    $env:KUBECONTEXT = kubectl config current-context
    $env:KUBENS = kubectl config view --minify -o jsonpath='{..namespace}'
}

# as above, my short, hacky kubens alternative
function ksn {
    param (
        [Parameter(Mandatory = $false)]
        [string]$ns
    )
    if (!$ns) {
        $ns = kubectl get namespace -o jsonpath='{range .items[*]}{.metadata.name}{"\n"}' | fzf
    }
    kubectl config set-context --current --namespace=$ns
    $env:KUBENS = $ns
}

# helper function
# to enable selecting and pre-filtering of resource names
function Get-K8sResource {
    param (
        [Parameter(Mandatory = $false)]
        $preFilter,
        [Parameter(Mandatory = $true)]
        $type
    )
    if ($preFilter) {
        return ([string[]](kubectl get $type --no-headers -o custom-columns=:.metadata.name | Select-String $preFilter ) | fzf -1 --header="Select $($type):" )
    } else {
        return ((kubectl get $type --no-headers -o wide | fzf --header="Select $($type):") -split "\s+")[0]
    }
}

# helper function
# to execute certain commands against a container inside a pod
# returns straight away if only one container exists
function Get-ContainerName {
    param ( 
        [Parameter(Mandatory = $true)]   
        [string]$pod 
    )
    return (kubectl get pod $pod -o jsonpath='{range .spec.containers[*]}{@.name}{"\n"}{end}' | fzf -1 --header="Select container:")
}

# quick shell into a running pod/container
function kssh {
    param (
        [Parameter(Mandatory = $false)]
        [string]$preFilter
    )
    $pod = Get-K8sResource $preFilter -type "pod"
    $container = Get-ContainerName $pod
    
    Write-Host "kubectl exec -it $pod -c $container -- /bin/bash || /bin/sh || /bin/ash/"
    kubectl exec -it $pod -c $container -- /bin/bash || /bin/sh || /bin/ash/
}

# quick logs from a running pod/container
function kl {
    param (
        [Parameter(Mandatory = $false)]
        [string]$preFilter
    )

    $pod = Get-K8sResource $preFilter -type "pod"
    $container = Get-ContainerName $pod

    Write-Host "$RED>>$YELLOW $pod $RED>$GREEN $container$END"
    kubectl logs $pod -c $container
}

# quickly get secrets and their decoded values
function ks {
    param (
        [Parameter(Mandatory = $false)]
        [string]$preFilter,
        [Parameter(Mandatory = $false)]
        [switch]$all
    )

    $secret = Get-K8sResource $preFilter -type "secret"
    Write-Host $MAGENTA"> "$secret

    $secret_obj = (kubectl get secret $secret -o json | ConvertFrom-Json)

    if ($all) {
        foreach ($item in $secret_obj.data.PSObject.Properties) {
            Write-Host $YELLOW">> "$($item.Name)": "$RED$(base64 -d $item.Value)$END
        }
    } else {
        $data = ($secret_obj.data.PSObject.Properties.Name | fzf -1 --header="Select Data to decode:")
        Write-Host $YELLOW">> "$($data)": "$RED$(base64 -d $secret_obj.data.$data)
    }
}

# quickly describe a k8s resource
function kd {
    param (
        [Parameter(Mandatory = $false)]
        [string]$type,
        [Parameter(Mandatory = $false)]
        [string]$preFilter
    )
    if ($type) {
        $resourceType = $type
    } else {
        $resourceType = (kubectl api-resources -o name | fzf --header="Select resource type:")
    }

    $resource = Get-K8sResource -preFilter $preFilter -type $resourceType

    kubectl describe $resourceType $resource
}


# quick method to drain nodes, use carefully!
function kdn {
    $node = Get-K8sResource -type "node"

    k drain $node --delete-emptydir-data --ignore-daemonsets --force
}

# number of pods on a node
function knp {
    $node = Get-K8sResource -type "node"
    Write-Host $node
    k describe node $node | findstr "Non-terminated Pods:"
}