Variable groups in Azure DevOps are a feature that allows you to store values that you want to make available across multiple pipelines. These values can be passwords, API keys, service endpoints, or any other data that you want to keep secure and use in your build and release pipelines. Here’s a detailed overview of variable groups in Azure DevOps:

1. Purpose of Variable Groups:

   • Reusability: Instead of defining the same variables in multiple pipelines, you can define them once in a variable group and link this group to any pipeline.
   • Security: Sensitive information like secrets, tokens, or passwords can be stored securely in variable groups and marked as secret. This ensures that the values are hidden in the logs and protected.

2. Creating Variable Groups:

   • You can create variable groups in the Azure DevOps portal under the Pipelines section.
   • When creating a variable group, you can add as many variables as you need, specifying their names and values.
   • For sensitive information, you can tick the “lock” icon to treat them as secrets.

3. Linking Variable Groups to Pipelines:

   • Once a variable group is created, it can be linked to build and release pipelines.
   • In your pipeline YAML file, you can reference a variable group using the variables key and specify the group’s name.
   • This makes all the variables in the group available in your pipeline steps.

4. Scope of Variable Groups:

   • Variable groups can be scoped to specific environments, allowing you to have different values for variables depending on the deployment environment (like Development, Staging, Production).

5. Managing Access:

   • You can control who has access to variable groups by setting permissions. This is important for maintaining the security of sensitive data.

6. Using Variable Groups in Tasks:

   • In your pipeline tasks, you can reference the variables defined in your variable group as you would with any other pipeline variable.

7. Integrating with Azure Key Vault:

   • Azure DevOps can integrate with Azure Key Vault, allowing you to link secrets from Key Vault directly into your variable groups for enhanced security and centralized secret management.

Variable groups are a powerful feature in Azure DevOps, helping to simplify pipeline configuration, maintain security for sensitive data, and improve maintainability and consistency across your CI/CD workflows.