TFS 2017 | Team Services
Use a variable group to store values that you want to make available across multiple release definitions. Variable groups are defined and managed in the Library tab of the Build & Release hub.
Variable groups can only be used in release definitions in TFS 2017 and Team Services at present. They cannot yet be used in build definitions.
Use a variable group
To use a variable group in a release definition, open the definition, select the Variables tab, and then choose Link variable group(s). When a variable group is linked to a release definition, all the variables in the group are available for use in all environments of that definition.
You cannot link a variable group to a specific environment in a release definition at present.
Any changes made centrally to a variable group, such as a change in the value of a variable or the addition of new variables, will automatically be made available to all the release definitions in which the variable group is used.
Variable groups follow the library security model.
Link secrets from an Azure Key vault as variables
Link an existing Azure key Vault to a variable group and map selective vault secrets to the variable group.
Choose Link secrets from an Azure key vault as variables, and specify your Azure subscription end point and the name of the vault containing your secrets. You must have at least Get and List permissions on the vault.
Choose + Add to select specific secrets from your vault that will be mapped to this variable group.
Only the secret names are mapped to the variable group, not the secret values. The latest version of the value of each secret is fetched from the vault and used in the release definition linked to the variable group during the release.
Any changes made to existing secrets in the key vault, such as a change in the value of a secret, will be made available automatically to all the release definitions in which the variable group is used.
When new secrets are added to the vault, they are not made available automatically to all the release definitions. New secrets must be explicitly added to the variable group in order to make them available to release definitions in which the variable group is used.