Category: Infrastructure

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##[error]Script failed with error: Error: Unable to locate executable file: ‘pwsh’.

In AzureCLI@2 you may choose from a variety of options when it comes on how this task will be executed on the agent machine. I usually choose powershell for windows machines and powershell core for Unix based machines (pwsh).

Recently I got an error on a Windows machine when using Powershell core. The latest version of powershell which is currently on 7.* version can be used as pscore in the AzureCLI@2 task.

      - task: AzureCLI@2
        displayName: az cli task
        inputs:
          azureSubscription: 'SERVICE-CONNECTION'
          scriptType: 'pscore'
          scriptLocation: 'inlineScript'
          inlineScript: |
           script

Error message:

##[error]Script failed with error: Error: Unable to locate executable file: ‘pwsh’. Please verify either the file path exists or the file can be found within a directory specified by the PATH environment variable. Also verify the file has a valid extension for an executable file.

Solution:

In order to bypass this problem you should make sure that the latest version of powershell which is multiplatform should be installed on your system. At the time of this article this version is 7.*

After installing powershell you should make a restart also on the machine in order for the environmental variables to be added on PATH. Then you can execute your pwsh tasks on your agent machines.

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Initialize and format windows disk with powershell

Sometimes you may need to automatically create windows disk for a virtual server using an automation mechanism. With the below powershell you can initialize a new emtpy disk with GPT partition and format it according to your needs.

You can get your available disks using:

Get-Disk

You can use the below powershell and change the below settings:

DriveLetter : What your drive letter will be
AllocationUnitSize: Default is 4k, but in my case I define 64k
DiskNumber: number of disk from Get-Disk command
NewFileSystemLabel: name of the volume

 Initialize-Disk -number 4 -partitionstyle GPT ; New-Partition -DiskNumber 4 -UseMaximumSize ; Format-Volume -DriveLetter G -FileSystem NTFS -AllocationUnitSize 65536 -NewFileSystemLabel Volume-Name

After applying the volume will be created and initialized.

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Enable debug logs on Azure DevOps pipelines

In some cases you may need to troubleshoot your azure devops tasks inside a job and get a more detailed output than the default. You can enable a detailed log output using predefined variables. In more detail you can use System.Debug and set it to true.

variables:
  - name: System.Debug
    value: true

By doing so you will get more debug messages as shown in the below screenshot.

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kubectl commands cheat sheet for daily kubernetes administration

This is a cheat sheet for basic k8s commands that one k8s administrator can use daily.

Apply a YAML definition on k8s-cluster:

kubectl apply -f pod.yaml

Apply a definition on specific namespace:

Kubectl apply -f kati.yml -n namespacename

Create a new namespace:

kubectl create ns namespacename

Set k8s cluster context:

kubectl config use-context geralexgr-aks

Get k8s cluster context:

kubectl config view

Create a deployment:

kubectl create deployment new-app --image=hello-world:latest

Delete a deployment:

kubectl delete deployment nginx -n nginx

Describe a service:

Kubectl describe service/myservice

Get logs for pod:

Kubectl logs pod-123

Get cluster namespaces:

kubectl get namespace

Set active namespace:

kubectl config set-context --current --namespace nginx

Delete a pod:

kubectl delete pod nginx-pod

Scale a deployment:

kubectl scale --replicas=5 deployment/deploymentname

Get pods with labels:

kubectl get pods --show-labels

Get cluster scoped resources:

kubectl api-resources