Adding documentation for certificate renewal

Signed-off-by: Pravin Pushkar <ppushkar@microsoft.com>

daprdocs/content/en/reference/cli/dapr-mtls/_index.md

@@ -32,6 +32,7 @@ dapr mtls [command]
 ```txt
 expiry              Checks the expiry of the root certificate
 export              Export the root CA, issuer cert and key from Kubernetes to local files
+renew-certificate   Rotates root CA, issuer cert and issuer key in Kubernetes secret used by Sentry service
 ```
 
 ### Command Reference
@@ -40,6 +41,7 @@ You can learn more about each sub command from the links below.
 
 - [`dapr mtls expiry`]({{< ref dapr-mtls-expiry.md >}})
 - [`dapr mtls export`]({{< ref dapr-mtls-export.md >}})
+- [`dapr mtls renew-certificate`]({{< ref dapr-mtls-renew-certificate.md >}})
 
 ### Examples
 

daprdocs/content/en/reference/cli/dapr-mtls/dapr-mtls-renew-certificate.md

@@ -0,0 +1,73 @@
+---
+type: docs
+title: "mtls renew certificate CLI command reference"
+linkTitle: "mtls renew certificate"
+description: "Detailed information on the mtls renew certificate CLI command"
+weight: 3000
+---
+
+### Description
+This command can be used to renew expiring Dapr certificates in Kubernetes cluster.
+It renews root CA certificate, issuer certificate and issuer key.
+
+### Supported platforms
+
+- [Kubernetes]({{< ref kubernetes >}})
+
+### Usage
+
+```bash
+dapr mtls renew-certificate [flags]
+```
+
+### Flags
+
+| Name           | Environment Variable | Default           | Description                                 |
+| -------------- | -------------------- | ----------------- | ------------------------------------------- |
+| `--help`, `-h` |                      |                   | help for renew-certificate
+| `--kubernetes`, `-k` |                      | `false` | supprted platform|                             |
+| `--valid-until`  |                      | 365 days |  Validity for newly created certificates |
+| `--restart`  |                      | false |  Restarts Dapr control plane services (Sentry service, Operator service and Placement server) |
+| `--timeout`  |                      | 300 sec |  The timeout for the certificate renewal process |
+| `--ca-root-certificate`  |                      |  |  User provided root certificate pem file path|
+| `--issuer-public-certificate`  |                      |  |  User provided issuer certificate pem file path|
+| `--issuer-private-key`  |                      |  |  User provided issue private key file path|
+| `--private-key`  |                      |  |  User provided root.key file which is used to generate root certificate|
+
+### Examples
+
+#### Renew certificates by generating fresh new certificates
+Generates new root and issuer certificates for Dapr kubernetes cluster with a default validity of 365 days.
+```bash
+dapr mtls renew-certificate -k
+```
+Generates new root and issuer certificates for kubernetes cluster with a default validity of 365 days and restart the control plane services.
+```bash
+dapr mtls renew-certificate -k --restart
+```
+Generates new root and issuer certificates for kubernetes cluster with a given validity.
+```bash
+dapr mtls renew-certificate -k --valid-until <no of days>
+```
+Generates new root and issuer certificates for kubernetes cluster with a given validity and restart the control place services.
+```bash
+dapr mtls renew-certificate -k --valid-until <no of days> --restart
+```
+#### Renew certificate by using user provided certificates
+Rotates certificate of your kubernetes cluster with provided ca.pem, issuer.pem and issuer.key file path and restart the control plane services
+```bash
+dapr mtls renew-certificate -k --ca-root-certificate <ca.pem> --issuer-private-key <issuer.key> --issuer-public-certificate <issuer.pem> --restart
+```
+Rotates certificate of your kubernetes cluster with provided ca.pem, issuer.pem and issuer.key file path.
+```bash
+dapr mtls renew-certificate -k --ca-root-certificate <ca.pem> --issuer-private-key <issuer.key> --issuer-public-certificate <issuer.pem>
+```
+#### Renew certificates by generating fresh certificates using provided root private key
+Uses existing private root.key to generate new root and issuer certificates for kubernetes cluster with a given validity for created certs.
+```bash
+dapr mtls renew-certificate -k --private-key myprivatekey.key --valid-until <no of days>
+```
+Uses existing private root.key to generate new root and issuer certificates for kubernetes cluster with a default validity of 365 days for created certs.
+```bash
+dapr mtls renew-certificate -k --private-key myprivatekey.key
+```