Category Archives: Helm

Creating custom SQL Server Helm charts

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In my previous post I went through how to deploy SQL Server to Kubernetes using Helm in which I used the SQL Server chart that is available in the Helm Hub.

That’s great but what if we want to create our own charts? Let’s run through creating a simple SQL Server chart and deploying to Kubernetes (AKS).

First, ensure that Tiller (the server-side component of Helm) is installed on your cluster: –

helm init

Then create a directory to deploy the new chart into: –

mkdir C:\Helm

Navigate to the new directory: –

cd C:\Helm

And now create the new chart!

helm create testsqlchart

OK, what that has done is create an empty chart so we need to drop in our yaml configuration files.

Navigate to templates directory: –

cd testsqlchart/templates

Remove the template yaml files: –

rm deployment.yaml
rm service.yaml
rm ingress.yaml

Re-create deployment.yaml: –

apiVersion: apps/v1beta1
kind: Deployment
metadata:
  name: sqlserver
spec:
  replicas: 1
  template:
    metadata:
      labels:
        name: sqlserver
    spec:
      containers:
      - name: sqlserver1
        image: mcr.microsoft.com/mssql/server:2019-CTP2.2-ubuntu
        ports:
        - containerPort: 1433
        env:
        - name: SA_PASSWORD
          value: "Testing1122"
        - name: ACCEPT_EULA
          value: "Y"

Re-create service.yaml file: –

apiVersion: v1
kind: Service
metadata:
  name: sqlserver-service
spec:
  ports:
  - name: sqlserver
    port: 1433
    targetPort: 1433
  selector:
    name: sqlserver
  type: LoadBalancer

N.B. – Be careful when doing this, I’ve found that sometimes that Helm doesn’t like the format of the files. Re-creating in VS Code seems to do the trick.

Go back one directory: –

cd C:\Helm

And now we can test a deployment with –dry-run: –

helm install --dry-run --debug ./testsqlchart

If you get the following error: –

Tiller needs to be re-initialised: –

# delete current tiller deployment
kubectl delete deployment tiller-deploy --namespace kube-system

# create a service account
kubectl create serviceaccount --namespace kube-system tiller

# create clusterrolebinding
kubectl create clusterrolebinding tiller-cluster-rule --clusterrole=cluster-admin --serviceaccount=kube-system:tiller

# re-initialise tiller
helm init --service-account tiller --upgrade

Once the dry run returns no errors, you’re good to go!

helm install ./testsqlchart --name testsqlserver

To check the status: –

helm list

And you can monitor the creation of the deployment/service by running the usual kubectl commands: –

kubectl get deployments

kubectl get pods

kubectl get services

And that’s a custom SQL Server chart deployed into Kubernetes. SQL can be accessed by using the external IP of the service created.

Finally, to delete the deployed chart: –

helm delete testsqlserver

Thanks for reading!

Deploying SQL Server to Kubernetes using Helm

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In previous posts I’ve run through how to deploy sql server to Kubernetes using yaml files. That’s a great way to deploy but is there possibly an easier way?

Enter Helm. A package manager for Kubernetes.

Helm packages are called charts and wouldn’t you know it? There’s a chart for SQL Server!

Helm comes in two parts. Helm itself is the client side tool, and tiller, which is the server side component. Details of what each part does can be found here.

So the first thing to do is install Helm. Now you can download the installers from the website here but I found the easiest way to install Helm locally was to install the Kubernetes extension for VS Code. Installing that extension will ask if you want to install other tools, one of which being helm. Nice and easy!

Now install tiller on your cluster (if you don’t have a cluster setup, I have a guide to building one in AKS here): –

helm init

Now search for the mssql-linux package: –

helm search stable/mssql-linux

And deploy!

helm install --name sql-server stable/mssql-linux --set acceptEula.value=Y --set sapassword=Testing1122 --set edition.value=Developer

N.B. – If you get the following error: –

Error: release sql-server failed: namespaces “default” is forbidden:
User “system:serviceaccount:kube-system:default” cannot get namespaces in the namespace “default”

Run the following and then retry the deployment: –

kubectl create clusterrolebinding permissive-binding --clusterrole=cluster-admin --user=admin --user=kubelet --group=system:serviceaccounts;

You can check the progress of the deployment by running the following: –

kubectl get deployments

kubectl get pods

kubectl get services

You may have noticed that the service does not have an external IP. So we can’t connect externally to the SQL instance running in the pod. In order to connect, let’s spin up another pod which has sqlcmd installed and enter a bash session: –

kubectl run sqltools --image=microsoft/mssql-tools -ti --restart=Never --rm=true -- /bin/bash

Now we can connect using sqlcmd: –

sqlcmd -S sql-server-mssql-linux -U sa

And now run a test query: –

SELECT @@VERSION;
GO

And that’s how to deploy SQL Server to Kubernetes using Helm! Pretty cool imho.

Finally to delete the deployment: –

helm delete sql-server

Thanks for reading!