The Azure Key Vault FlexVol CSI driver is a Container Storage Interface (CSI) driver that allows you to connect your AKS (Azure Kubernetes Service) cluster to Azure Key Vault. This driver allows you to use Azure Key Vault to store and manage sensitive information, such as secrets and keys, used by your applications running on AKS.
Advantages of CSI
The advantages of using the CSI driver include:
- Improved security: By using Azure Key Vault to store and manage sensitive information, you can improve the security of your applications running on AKS by keeping sensitive information out of your application code and configuration files.
- Improved scalability and availability: By using Azure Key Vault, you can take advantage of Azure’s global scale and availability to ensure that your sensitive information is always available and accessible to your applications running on AKS.
- Improved manageability: By using Azure Key Vault, you can take advantage of Azure’s built-in management features to manage your sensitive information, such as backup, disaster recovery, and auditing.
Disadvantages of CSI
While using CSI driver has many advantages, there are also some potential disadvantages to consider:
- Complexity: Integrating the Azure Key Vault FlexVol CSI driver with an AKS cluster can be complex and requires a good understanding of the various components involved. This can make it more challenging to set up and manage the driver.
- Cost: Using Azure Key Vault FlexVol CSI driver may incur additional costs for using Azure Key Vault and the associated resources such as storage and network traffic.
- Limited support for some configurations: The Azure Key Vault FlexVol CSI driver is not currently supported in all configurations, such as AKS clusters running on Azure Stack.
- Latency: Depending on the location of the AKS cluster, there may be some latency when accessing data stored in Azure Key Vault which could affect the performance of the application.
- Compatibility: The Azure Key Vault FlexVol CSI driver may not be compatible with all existing applications, as it requires applications to be written in a way that allows them to use the driver.
Possible security issues
Yes, there are some potential security issues that can be exposed when using the Azure Key Vault FlexVol CSI driver. Here are a few examples:
- Data leak: If the driver is not properly configured or if there are vulnerabilities in the driver, sensitive information stored in Azure Key Vault can be leaked.
- Privilege escalation: If an attacker is able to gain access to the driver, they may be able to escalate their privileges and gain access to sensitive information stored in Azure Key Vault.
- Unauthorized access: If an attacker is able to gain access to the driver, they may be able to access sensitive information stored in Azure Key Vault without proper authentication or authorization.
- Man-in-the-middle attacks: If an attacker is able to intercept the communication between the driver and Azure Key Vault, they may be able to steal sensitive information or inject malicious data.
- Misconfiguration: If the driver is not properly configured, it may be susceptible to attack or data leaks.
It is important to be aware of these security issues and to take appropriate measures to mitigate them. For example, by using Azure Key Vault, you can take advantage of Azure’s built-in security features to protect your sensitive information, such as backup, disaster recovery, and auditing.
Install Azure Key Vault FlexVol CSI driver
# Add the FlexVolume repository helm repo add flexvolume https://raw.githubusercontent.com/Azure/kubernetes-keyvault-flexvol/master/helm-charts/ # Create a namespace for the driver kubectl create namespace kv-flexvol-ns # Install the driver helm install kv-flexvol flexvolume/kubernetes-keyvault-flexvol \ --set keyvaultName=myKeyVault \ --set keyvaultNamespace=kv-flexvol-ns
In this example, we are adding the FlexVolume repository, creating a namespace for the driver, and then installing the driver using the Helm package manager. The
keyvaultNamespace values will need to be set to the name and namespace of your Key Vault.
Sample code to fetch secret from keyvault using CSI driver
Here is an example of how to connect to Key Vault using the Azure Key Vault FlexVol CSI driver and fetch a secret:
apiVersion: v1 kind: Pod metadata: name: my-pod spec: containers: - name: my-container image: my-image env: - name: MY_SECRET valueFrom: secretKeyRef: name: my-keyvault-secret key: mysecret volumeMounts: - name: my-keyvault-volume mountPath: /mnt/secrets volumes: - name: my-keyvault-volume flexVolume: driver: "azure/kv" options: keyvault: myKeyVault keyvaultNamespace: kv-flexvol-ns usepodidentity: "true" tenantid: "your tenant id" clientid: "your client id"
In this example, we are creating a Pod with a single container, and then adding a FlexVolume to the Pod that connects to the Key Vault. The volume is mounted at the
/mnt/secrets path within the container. Additionally, an environment variable
MY_SECRET is created and set to the value of the secret named “mysecret” from the keyvault named “my-keyvault-secret”. The
clientid options will need to be set to the name and namespace of your Key Vault and the necessary credentials to connect to it.