Category: Devops

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Dynamically checkout github repository based on parameter

In some cases, the DevOps team may need to checkout multiple github repositories in the current working directory of the pipeline. By default the pipeline will download the code of the repository where it belongs.

The below pipeline will download a github repository based on a parameter that user provides. In order to accomplish that you will need a service connection with your github account/organization.

Then using the below pipeline you can download a repository with a specific branch by providing the repository name.

trigger:
- main

pool:
  vmImage: ubuntu-latest

parameters:
- name: repoparam
  type: string
  default: reponame
- name: branchparam
  type: string
  default: main

variables:
  - name: repositoryvar
    value: ${{parameters.repoparam}}
  - name: branchvar
    value: ${{parameters.branchparam}}


resources:
  repositories:
    - repository: gitrepo
      type: github
      name: geralexgr/$(repositoryvar)
      ref: $(branchvar)
      endpoint: geralexgr

steps:
- checkout: gitrepo
  displayName: download repository

For example given that I have created a repository geralexgr/terraform-az-lin-win I will provide only the name of it terraform-az-lin-win and the main branch.

When running the pipeline the selected repository will be downloaded into C:agent/work/buildID/s or /home/vsts/work/buildID/s

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Start multiple VMs using parameters with Azure DevOps pipeline

In this article I will explain how one can start multiple VMs on Azure using a pipeline automation. The steps you need to follow:

First create a service connection with your subscription. You should navigate to service connections -> azure resource manager and then select service principal (automatic)

You will then have to select the scope* the subscription or resource group this service connection will access.

In my scenario I added a friendly name of the subscription as Azure Subscription Service Connection

trigger: none
pr: none
parameters:
– name: vms
type: object
default: ["ubuntu1","windows-1"]
pool:
vmImage: ubuntu-latest
jobs:
– job: startvmjob
displayName: Start VMs
steps:
– checkout: none
– ${{ each vm in parameters.vms }}:
– task: AzureCLI@2
displayName: starting vm ${{vm}}
inputs:
azureSubscription: 'Azure Subscription Service Connection'
scriptType: 'pscore'
scriptLocation: 'inlineScript'
inlineScript: |
$vmrequest = az vm list | ConvertFrom-Json | Where-Object {$_.Name -Match "${{vm}}"}
az vm start –resource-group $vmrequest.resourcegroup –name $vmrequest.name
view raw start-vms-azure-pipeline hosted with ❤ by GitHub

When you run the pipeline you will need to provide the VM names. You can also run this pipeline on a schedule using a cron task. My vms are ubuntu1, windows-1

By running the pipeline

Then by navigating on Azure you can notice the VM as started.

Video tutorial on YouTube:

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Azure DevOps agent cannot checkout GitHub repository

Recently I faced an issue with my Azure DevOps self hosted container agents. They could not checkout the git repositories and the build stopped due to the default timeout of 60 minutes per run.

This happened for multiple builds, as a result I had to investigate the reason behind this error.

By checking the logs inside the container on the C:\agent\_diag folder I could recognize an error message like the below:

A session for this agent already exists.
Agent connect error: The task agent xxx already has an active session for owner xxx.. Retrying until reconnected.

By searching online, I figured out that this is a reported bug on previous agents versions. In order to resolve, I updated and reconfigured the agent. You can update the agent, either from the GUI or by creating a new container and installing the latest version of azure devops agent.

In order to reconfigure the agent I first took an interactive shell on it.

docker exec -it agent-name powershell.exe

Then inside C:\agent run the below commands.

Reconfigure the agent

This is a temporary fix for your agent. If the problem persists you should open a support ticket on Microsoft to troubleshoot the issue.

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Install and configure kubernetes dashboard for Docker Desktop local cluster

Kubernetes dashboard is a helpful UI application that presents all your resources inside your k8s cluster. As most people prefer GUI instead of single commands, this tool can make your k8s administration experience better.

When you install docker desktop on your local or development machines, you can select to also include a k8s installation with it. You can locate all your Kubernetes settings using the Docker Desktop UI.

The local cluster is composed of only one node, the computer itself.

In order to install dashboard first run the below kubectl apply command:

kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.5.0/aio/deploy/recommended.yaml

Then you will need to run kubectl proxy

Then open GUI Dashboard.

Kubernetes Dashboard

The below dialog will appear.

We will examine the Token example.

Create and save the below definition as s.yml. Then apply this configuration with kubectl apply -f s.yml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kubernetes-dashboard

Create and save the below definition as r.yml. Then apply this configuration with kubectl apply -f r.yml

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin-user
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kubernetes-dashboard

Then run the below command:

kubectl -n kubernetes-dashboard get secret $(kubectl -n kubernetes-dashboard get sa/admin-user -o jsonpath="{.secrets[0].name}") -o go-template="{{.data.token | base64decode}}"

The output will be your Token.

Paste the Token on the previous link, and then you will have a working dashboard for your local cluster.

You can also skip the Token procedure. Simply run the below command:

kubectl patch deployment kubernetes-dashboard -n kubernetes-dashboard --type 'json' -p '[{"op": "add", "path": "/spec/template/spec/containers/0/args/-", "value": "--enable-skip-login"}]'

Then you will see a skip button near the sign in

Kubernetes dashboard:

Deploy and Access the Kubernetes Dashboard | Kubernetes

Token procedure:

dashboard/creating-sample-user.md at master · kubernetes/dashboard (github.com)