Connecting Your Azure Pods App to MSSQL Server on Azure VM

Learn how to connect your Azure Kubernetes Service (AKS) pods to an MSSQL Server installed on an Azure Virtual Machine. This guide provides solutions for various network configurations.
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This video is based on the question https://stackoverflow.com/q/67875474/ asked by the user 'Cam Lâm Văn' ( https://stackoverflow.com/u/16155991/ ) and on the answer https://stackoverflow.com/a/67882968/ provided by the user 'Charles Xu' ( https://stackoverflow.com/u/9773937/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Connecting Your Azure Pods App to MSSQL Server on Azure VM: A Step-by-Step Guide

Are you facing difficulties connecting your Azure Kubernetes Service (AKS) pods to an MSSQL Server that is installed on an Azure Virtual Machine (VM)? You’re not alone! Many newcomers to Azure encounter connectivity issues, but there’s good news: this guide will guide you on how to solve this problem effectively.

Understanding the Problem

When deploying an application in a Kubernetes cluster on Azure, you might need to connect to an MSSQL Server hosted on an Azure VM. However, errors may arise, such as the inability to connect using the private IP of the VM. This issue can stem from several factors including networking configurations and security rules.

Possible Scenarios

To address your connectivity issues, let's break down the solution based on how you've set up your Azure resources:

AKS Cluster with Kubelet Network Type

VM in VNet A and AKS in VNet B:

Solution: Create a service with an internal load balancer for the pod and peer the two VNets (Virtual Networks).

VM and AKS in the Same VNet:

Solution: Simply create a service with an internal load balancer for the pod.

AKS Cluster with CNI Network Type

VM in VNet A and AKS in VNet B:

Solution: Peer the two VNets to allow traffic between them.

VM and AKS in the Same VNet:

Solution: You don’t need to do anything extra; the connection should work seamlessly.

Verifying Security Groups

Regardless of the network type you are using, there is one crucial step that applies to all configurations: checking Network Security Group (NSG) rules. It's vital to ensure that:

The inbound traffic to your VM is allowed on the MSSQL port (default is 1433).

You correctly configure the NSG to bypass any restrictions that could hinder the connectivity.

Steps to Check NSG Rules

Navigate to the Azure Portal:

Sign in to your Azure account and go to your Resource Group where your VM and AKS resides.

Select the Virtual Machine:

Locate and click on your Azure VM.

In the settings pane, find and click on "Networking."

Check Inbound Ports:

Ensure that there is a rule allowing traffic on TCP port 1433 (or your designated MSSQL port) from the IP range of your AKS pods.

Modify Rules if Necessary:

If you see restrictions, create a new inbound security rule to allow traffic from the AKS subnet or from the specific IP address that your pods will use.

Conclusion

By following these steps and strategies based on your network configuration, you should be well on your way to successfully connecting your Azure pods application to the MSSQL server installed on your Azure VM. Remember to keep an eye on the networking configurations and security settings—these are often the culprits for connectivity issues.

If you are still encountering problems, don’t hesitate to reach out to Azure support or consult the Azure documentation for more detailed guidance specific to your setup. Happy coding!