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Query servers disk size – Azure Log Analytics

Log Analytics can be a powerful monitoring tool for your infrastructure as you can query various metrics that are important for your servers availability like disk space.

The below query can be used to get free space for your Linux VM disks.

 InsightsMetrics
| where Origin == "vm.azm.ms"
    and Namespace == "LogicalDisk"  
    and Name == "FreeSpaceMB"
| extend Disk=tostring(todynamic(Tags)["vm.azm.ms/mountId"]),
    Disk_Size_GB=(todynamic(Tags)["vm.azm.ms/diskSizeMB"]) / (1024)
| summarize Disk_Free_Space_GB = avg(Val) / (1024)
    by Computer,
    Disk, Disk_Size_GB, _ResourceId
| where Disk in ('sda1', 'sdb1', 'sdc1', 'sdd1','/')
| project Computer, Disk, Disk_Size_GB, Disk_Free_Space_GB

You can also select the scope of the query in order to get results for specific resources/resource groups.

The result will bring all disks size and free space that their name is included in the list

('sda1', 'sdb1', 'sdc1', 'sdd1','/')

The same query with a small change can be applied also for windows vms in order to get the available space for your C: drive.

 InsightsMetrics
| where Origin == "vm.azm.ms"
    and Namespace == "LogicalDisk"  
    and Name == "FreeSpaceMB"
| extend Disk=tostring(todynamic(Tags)["vm.azm.ms/mountId"]),
    Disk_Size_GB=(todynamic(Tags)["vm.azm.ms/diskSizeMB"]) / (1024)
| summarize Disk_Free_Space_GB = avg(Val) / (1024)
    by Computer,
    Disk, Disk_Size_GB, _ResourceId
| where Disk in ('C:')
| project Computer, Disk, Disk_Size_GB, Disk_Free_Space_GB

Finally you can pin this result inside an Azure dashboard by clicking pin and select the specific dashboard.

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Scan azure devops repositories for credentials and passwords

DevSecOps practices are important for organizations especially when it comes to code repositories. Your code should avoid hard coded passwords and secrets for many reasons as a leak may occur. In this guide I will examine how you can massively scan Azure DevOps repositories for security leaks as passwords and secrets with gitleaks utility.

https://github.com/gitleaks/gitleaks

Simon has provided a very useful script that you can use in order to download all your repositories from Azure DevOps.

Cloning all repositories from Azure DevOps using Azure CLI – Simon Wahlin

When you execute the script, all the repositories will be downloaded inside your project folder.

Then you will need to install gitleaks and execute for each repository.

$folder_for_cleanup = "C:\Users\geralexgr\Documents\AzureRepos"
Get-ChildItem $folder_for_cleanup | Sort -Property FullName | ForEach-Object {
                gitleaks detect -s $_.FullName -v >> gitleaks-results.txt
                echo "######################################################################################################" >> gitleaks-results.txt
            }

The scan will go through each repository and scan for leaks. The output will be stored in gitleaks-result text file.

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Automatic rollback procedure for Azure DevOps

Azure devops pipelines provide a variety of tools for automated procedures. One mechanism that administrators can build using the YAML structure is an automated rollback mechanism during a deployment.

This means that after a deployment you can revert the previous state using your YAML tasks without having to redeploy. Another case would be a broken deployment which can be identified by monitoring tools and then a validation could approve or not the final release. This is exactly depicted in the below image. After releasing a version we have a validation step that requires manual approval from an administrator. If the validation is approved the release will proceed else the rollback will be triggered.

This mechanism is described below with YAML. Release stage includes release, validation and rollback jobs. Release job performs the actual release. Validation will depend on release job and will continue only if is approved. The rollback job will run only if validation failed which means that an administrator canceled the approval.

trigger: none
pr: none

stages:

- stage: releaseStage
  jobs:

  - deployment: release
    displayName: Release
    environment:
      name: dev
      resourceType: VirtualMachine
    strategy:
      runOnce:
        deploy:
          steps:
            - task: PowerShell@2
              displayName: hostname
              inputs:
                targetType: 'inline'
                script: |
                    deployment script here...
  
  - job: validation
    dependsOn: release
    pool: server
    steps:
    - task: ManualValidation@0
      inputs:
        notifyUsers: 'admin@domain.com'
        instructions: 'continue?'
        onTimeout: reject

  - deployment: rollback
    displayName: rollback
    dependsOn: validation
    condition: failed()
    environment:
      name: dev
      resourceType: VirtualMachine
    strategy:
      runOnce:
        deploy:
          steps:
            - task: PowerShell@2
              displayName: rolling back
              inputs:
                targetType: 'inline'
                script: |
                    rollback script here..
                    Write-Host "rollback"

When the release can be verified from the administrator the rollback will be skipped. This is the case when the validation is approved from the user.

Validation task will ask the user for a review.

On the other hand if validation is rejected the rollback stage will run.