Update doc for running rancheros on azure

content/os/v1.x/en/installation/running-rancheros/cloud/azure/_index.md

@@ -3,11 +3,9 @@ title: Azure
 weight: 110
 ---
 
-RancherOS is available as an image with Azure Resource Management. Please note that RancherOS is only offered in Azure Resource Management and not available in the Azure Service Management.
+RancherOS has been published in Azure Marketplace, you can get it from [here](https://azuremarketplace.microsoft.com/en-us/marketplace/apps/rancher.rancheros).
 
-> **Note:** Currently, we only have v0.3.1 available as an image in Azure and it does not support passing in cloud config files. We are working on adding a new version that has cloud config enabled. Also, only certain regions are supported with RancherOS on Azure.
-
-### Launching Rancheros through the Azure Portal
+### Launching RancherOS through the Azure Portal
 
 Using the new Azure Resource Management portal, click on **Marketplace**. Search for **RancherOS**. Click on **Create**.
 
@@ -26,3 +24,53 @@ After the VM has been provisioned, click on the VM to find the public IP address
 ```
 $ ssh rancher@<public_ip_of_vm> -p 22
 ```
+
+### Launching RancherOS with custom data
+
+_Available as of v1.5.2_
+
+Instance Metadata Service provides the ability for the VM to have access to its custom data. The binary data must be less than 64 KB and is provided to the VM in base64 encoded form.
+You can get more details from [here](https://docs.microsoft.com/en-us/azure/virtual-machines/linux/instance-metadata-service#custom-data)
+
+For example, you can add custom data through [CLI](https://docs.microsoft.com/en-us/azure/virtual-machines/linux/cli-ps-findimage):
+
+```
+# list images from marketplace
+az vm image list --location westus --publisher Rancher --offer rancheros --sku os --all --output table
+
+Offer      Publisher    Sku    Urn                            Version
+---------  -----------  -----  -----------------------------  ---------
+rancheros  rancher      os     rancher:rancheros:os:1.5.1     1.5.1
+rancheros  rancher      os152  rancher:rancheros:os152:1.5.2  1.5.2
+...
+
+# accept the terms
+az vm image accept-terms --urn rancher:rancheros:os152:1.5.2
+
+# create the vm
+AZURE_ROS_SSH_PUBLIC_KEY="xxxxxx"
+az vm create --resource-group mygroup \
+             --name myvm \
+             --image rancher:rancheros:os152:1.5.2 \
+             --plan-name os152 \
+             --plan-product rancheros \
+             --plan-publisher rancher \
+             --custom-data ./custom_data.txt \
+             --admin-username rancher \
+             --size Standard_A1 \
+             --ssh-key-value "$AZURE_ROS_SSH_PUBLIC_KEY"
+```
+
+The `custom_data.txt` can be the cloud-config format or a shell script, such as:
+
+```
+#cloud-config
+runcmd:
+- [ touch, /home/rancher/test1 ]
+- echo "test" > /home/rancher/test2
+```
+
+```
+#!/bin/sh
+echo "aaa" > /home/rancher/aaa.txt
+```