• 6 minutes

In this unit, you use the Azure CLI to grant your Java application access to the Azure Key Vault secrets.

You play the role of an IT operator, who manages those secrets and grants access to them.

Store secrets into Azure Key Vault

In your application, you had two secrets to store:

• ${azureDatabaseName} is the name of the PostgreSQL database that was configured earlier in the AZ_DATABASE_NAME environment variable. Type echo $AZ_DATABASE_NAME to see it.
• ${azureDatabaseUsername} is the name of the database username that was configured earlier in the AZ_DATABASE_USERNAME environment variable. Type echo $AZ_DATABASE_USERNAME to see it.
• ${azureDatabasePassword} is the name of the database password that was configured earlier in the AZ_DATABASE_PASSWORD environment variable. Type echo $AZ_DATABASE_PASSWORD to see it.

Let's create an Azure Key Vault instance and store those secrets in it:

AZ_KEY_VAULT_NAME=kv-${AZ_RESOURCE_GROUP}

az keyvault create \
    --name $AZ_KEY_VAULT_NAME \
    --resource-group $AZ_RESOURCE_GROUP \
    --location $AZ_LOCATION

az keyvault secret set \
    --vault-name $AZ_KEY_VAULT_NAME \
    --name azureDatabaseName \
    --value ${AZ_DATABASE_NAME}

az keyvault secret set \
    --vault-name $AZ_KEY_VAULT_NAME \
    --name azureDatabaseUsername \
    --value ${AZ_DATABASE_USERNAME}

az keyvault secret set \
    --vault-name $AZ_KEY_VAULT_NAME \
    --name azureDatabasePassword \
    --value ${AZ_DATABASE_PASSWORD}

Grant your application access to Azure Key Vault

To access Azure Key Vault, your Spring Boot application needs first to have an Azure identity assigned.

az spring app identity assign \
   --resource-group $AZ_RESOURCE_GROUP \
   --service $AZ_SPRING_CLOUD \
   --name application \
   --system-assigned

You also need to configure your Spring Boot application with two environment variables. The first variable is to enable Azure Key Vault. The second variable is to give the URL to your Azure Key Vault instance. This command can take several minutes to run.

az spring app update \
   --resource-group $AZ_RESOURCE_GROUP \
   --service $AZ_SPRING_CLOUD \
   --name application \
   --env \
   AZURE_KEYVAULT_ENABLED=true \
   AZURE_KEYVAULT_URI=https://$AZ_KEY_VAULT_NAME.vault.azure.net/

Then, you need to grant your application access to the Azure Key Vault instance.

AZ_SPRING_CLOUD_PRINCIPAL_ID=$(az spring app identity show --resource-group $AZ_RESOURCE_GROUP --service $AZ_SPRING_CLOUD --name application | jq --raw-output '.principalId')

az keyvault set-policy \
    --name $AZ_KEY_VAULT_NAME \
    --resource-group $AZ_RESOURCE_GROUP \
    --object-id $AZ_SPRING_CLOUD_PRINCIPAL_ID \
    --secret-permissions get list

Your application should now have the permissions to access the secrets stored in Azure Key Vault.