docs: add release cadence to readme (#163)

* docs: add release cadence to readme

* remove AKS engine references

Author: salaxander

README.md

@@ -9,18 +9,18 @@ Enables encryption at rest of your Kubernetes data in etcd using Azure Key Vault
 
 From the Kubernetes documentation on [Encrypting Secret Data at Rest]:
 
-> *[KMS Plugin for Key Vault is]* the recommended choice for using a third party tool for key management. Simplifies key rotation, with a new data encryption key (DEK) generated for each encryption, and key encryption key (KEK) rotation controlled by the user.
+> _[KMS Plugin for Key Vault is]_ the recommended choice for using a third party tool for key management. Simplifies key rotation, with a new data encryption key (DEK) generated for each encryption, and key encryption key (KEK) rotation controlled by the user.
 
 ⚠️ **NOTE**: Currently, KMS plugin for Key Vault does not support key rotation. If you create a new key version in KMS, decryption will fail since it won't match the key used for encryption when the cluster was created.
 
 💡 **NOTE**: To integrate your application secrets from a key management system outside of Kubernetes, use [Azure Key Vault Provider for Secrets Store CSI Driver].
 
 ## Features
 
-* Use a key in Key Vault for etcd encryption
-* Use a key in Key Vault protected by a Hardware Security Module (HSM)
-* Bring your own keys
-* Store secrets, keys, and certs in etcd, but manage them as part of Kubernetes
+- Use a key in Key Vault for etcd encryption
+- Use a key in Key Vault protected by a Hardware Security Module (HSM)
+- Bring your own keys
+- Store secrets, keys, and certs in etcd, but manage them as part of Kubernetes
 
 ## Getting Started
 
@@ -46,25 +46,25 @@ Now that Azure KMS provider is running in your cluster and the encryption config
 
 1. Create a new secret:
 
-    ```bash
-    kubectl create secret generic secret1 -n default --from-literal=mykey=mydata
-    ```
+   ```bash
+   kubectl create secret generic secret1 -n default --from-literal=mykey=mydata
+   ```
 
 2. Using `etcdctl`, read the secret from etcd:
 
-    ```bash
-    sudo ETCDCTL_API=3 etcdctl --cacert=/etc/kubernetes/certs/ca.crt --cert=/etc/kubernetes/certs/etcdclient.crt --key=/etc/kubernetes/certs/etcdclient.key get /registry/secrets/default/secret1
-    ```
+   ```bash
+   sudo ETCDCTL_API=3 etcdctl --cacert=/etc/kubernetes/certs/ca.crt --cert=/etc/kubernetes/certs/etcdclient.crt --key=/etc/kubernetes/certs/etcdclient.key get /registry/secrets/default/secret1
+   ```
 
 3. Check that the stored secret is prefixed with `k8s:enc:kms:v1:azurekmsprovider`. This indicates the Azure KMS provider has encrypted the data.
 
 4. Verify the secret is decrypted correctly when retrieved via the Kubernetes API:
 
-    ```bash
-    kubectl get secrets secret1 -o yaml
-    ```
+   ```bash
+   kubectl get secrets secret1 -o yaml
+   ```
 
-    The output should match `mykey: bXlkYXRh`, which is the encoded data of `mydata`.
+   The output should match `mykey: bXlkYXRh`, which is the encoded data of `mydata`.
 
 ## Rotation
 
@@ -74,6 +74,10 @@ Refer to [doc](docs/rotation.md) for steps to rotate the KMS Key on an existing
 
 The KMS Plugin for Key Vault project welcomes contributions and suggestions. Please see [CONTRIBUTING](CONTRIBUTING.md) for details.
 
+## Release
+
+Currently, this project releases monthly to patch security vulnerabilities, and bi-monthly for new features. We target the **first week** of the month for release.
+
 ## Code of conduct
 
 This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/). For more information, see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq) or contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional questions or comments.
@@ -82,9 +86,6 @@ This project has adopted the [Microsoft Open Source Code of Conduct](https://ope
 
 KMS Plugin for Key Vault is an open source project that is [**not** covered by the Microsoft Azure support policy](https://support.microsoft.com/en-us/help/2941892/support-for-linux-and-open-source-technology-in-azure). [Please search open issues here](https://github.com/Azure/kubernetes-kms/issues), and if your issue isn't already represented please [open a new one](https://github.com/Azure/kubernetes-kms/issues/new/choose). The project maintainers will respond to the best of their abilities.
 
-[AKS]: https://azure.microsoft.com/services/kubernetes-service/
-[AKS Engine]: https://github.com/Azure/aks-engine
-[Azure Key Vault Data Encryption]: https://github.com/Azure/aks-engine/blob/master/docs/topics/features.md#azure-key-vault-data-encryption
-[Encrypting Secret Data at Rest]: https://kubernetes.io/docs/tasks/administer-cluster/encrypt-data/#providers
-[example cluster configuration]: https://github.com/Azure/aks-engine/blob/master/examples/kubernetes-config/kubernetes-keyvault-encryption.json
-[Azure Key Vault Provider for Secrets Store CSI Driver]: https://github.com/Azure/secrets-store-csi-driver-provider-azure
+[aks]: https://azure.microsoft.com/services/kubernetes-service/
+[encrypting secret data at rest]: https://kubernetes.io/docs/tasks/administer-cluster/encrypt-data/#providers
+[azure key vault provider for secrets store csi driver]: https://github.com/Azure/secrets-store-csi-driver-provider-azure