I will be speaking at Tech Summit Nigeria 2022. This event is to be held in Lagos, Nigeria at the Microsoft ADC center. It is an event for Cloud & Mixed- Reality professionals & enthusiasts. The website for the is https://www.techsummitnigeria.com.
My session title is: “K8s is complex! Simplify its Deployment & Configuration“.
The abstract is: Understanding Kubernetes is complex. Designing its architecture is complex. Deploying it is complex. And Configuring it is complex. K8s in general are complex. Spend less time on getting your Kubernetes up and running and more time running your containerized apps!
In this session, Steve Buchanan will take you on a journey utilizing a tool named the AKS Construction Helper that can simplify your AKS Deployment & Configurations.
It was a fun session with an engaged audience! Here are some pictures from the session.
If you missed my session you can watch the replay here:
One of the top concerns I see from companies when architecting AKS is running out of IP addresses. This is commonly known as IP exhaustion. This concern would come up when selecting the network model for AKS specifically with Azure CNI.
Companies would lean towards Azure CNI at first but quickly opt for Kubenet. Azure CNI provides benefits on Azure. It has deeper integration between Kubernetes and Azure networking. With Azure CNI you don’t have to manually configure routing for traffic to flow from pods to other resources on Azure VNets. Pods get full network connectivity and can be reached via their private IP address. Supports Virtual Nodes (Azure Container Instances), it supports either Azure or Calico Network Policies and Windows containers. Azure CNI does however require more IP address space. The traditional Azure CNI assigns an IP address to every Pod from a subnet reserved for pods or pre-reserved set of IPs on every node. This method can lead to exhausting available IPs.
The alternative to Azure CNI with AKS is Kubenet. A lot of companies opt for Kubenet to avoid IP Exhaustion as it conserves IP address space. Kubenet assigns private IP addresses to pods. It does not have routing to Azure networking. In order to route from pods to Azure VNets you need to manually configure and manage user-defined routes (UDRs). With Kubenet a simple /24 IP CIDR range is able to support up to 251 nodes in an AKS cluster. This would give you support IPs for up to 27,610 pods (at 110 pods per node).
With Azure CNI the same /24 IP CIDR range would be able to support up to 8 nodes in the cluster supporting up to 240 pods (default max of 30 pods per node w/Azure CNI. Allocation of 31 IP address; 1 for the node + 30 for Pods.).
Here is a side by side breakdown of Kubenet and Azure CNI:
Capacity using ‘/24’ address range
251 nodes / 27,610 pods (110 pods / node)
8 nodes / 240 pods (30 pods / node)
Max nodes per cluster
400 (UDR max)
1,000 (or more)
NAT’ed / UDR /
Slightly greater (NAT hop)
Calico community support
Supported by Azure support and the Engineering team
Out of the Box Logging
/var/log/calico inside the container
Rules added/deleted in IPTables are logged on every host under /var/log/azure-npm.log
Best w/limited IP space Most pod comms within cluster UDR management is acceptable
Available IP space Most pod coms outside cluster No need to manage UDR Need advanced features
As you can see you can get a lot more pods on Kubenet and you will burn through a lot more IP’s with Azure CNI. One would think when using Azure CNI to just assign a large CIDR for the subnets like /16 instead of /24. This would work however most IT teams in the enterprise that are connecting AKS to existing networks don’t have that option based on the existing IP design and are stuck working with smaller IP address ranges they can use.
Microsoft has built a solution to the IP exhaustion problem. The solution is Azure CNI Overlay. Azure CNI Overlay for AKS has been around for a while but was recently released into public preview on 9/4/22. Azure CNI Overlay for AKS helps us avoid IP exhaustion with our AKS clusters. It does this by assigning using a private /24 IP CIDR range and assigning IPs from this for pods on every node.
After designing and architecting AKS the next step is to deploy your cluster/s. It is ideal to build your AKS deployments out as code.
This means taking your Azure infrastructure & AKS cluster/s design and scripting them as IaC (Infrastructure as Code). Scripting the AKS deployment vs manually deploying gives you documentation as code, standardization, & a templatized deployment for repeatability. You can deploy this code as is, place it in a pipeline for ease of deployment, in inner-source, or in a service catalog for access by multiple teams.
Microsoft has built a tool named the AKS Construction helper to accelerate building out your IaC for AKS. This tool is not as well-known as it should be. I wanted to blog about this tool to share this great resource that will save you tons of time. The AKS Construction helper was originally launched by Keith Howling of Microsoft. The core contributors to this tool have been Gordon Byers and Keith Howling with contributions from others as well.
The tool lets you select Operations Principles or Enterprise-Scale path for configuring the options.
This helps narrow down the overall design requirements of your AKS deployment.
The next section of the AKS Construction helper is to fine-tune your AKS deployment. This gives you the chance to tweak things like the cluster name, K8s version, resource group, region, to be created, IP and Cider, initial RBAC, SLA, autoscaling, upgrade configuration, cluster networking, add ons such as an ingress controller (App Gateway, NGINX, etc), monitoring such as Azure Monitor, Azure policy, service mesh, secret storage, Keda, GitOps with Flux, and even has a few options to deploy some sample apps. This is done across 5 tabs in the Fine tine and Deploy section.
After you have set all of the configurations for your cluster there is code available for you to copy on the Deploy tab. Again you have options for Az CLI, a Github Actions workflow, Terraform scripts or an ARM Template Parameters file. Running the deployment code will deploy your AKS cluster exactly how you have it configured in the AKS Construction helper tool.
I was a guest on Tech Talk with Kazeem again! The topic of discussion was Azure Arc Enabled Kubernetes for Beginners.
@KazeemCanTeach & @buchatech
@buchatech Azure Arc K8s book with O’Reilly
In the discussion with me and Microsoft MVP Kazeem Adegboyega, we talked about Azure Stack, AKS, Azure Arc: K8s, and GitOps! We talked about each technology and when to use them for what purpose and more.
I am giving a talk for the Data on Kubernetes Community (DoKC) Community next week. They are a user group like community that focuses on how to build and operate data-centric applications on Kubernetes. Be sure to check them out! The DoK website is: https://dok.community.
My talk is titled: “Running Stateful Apps in Kubernetes Made Simple“
ABSTRACT OF THE TALK
Eventually, the time will come to run a stateful app in Kubernetes. This can be a scary thing adding more moving parts to a Kubernetes cluster and deploying as well as managing your app on Kubernetes when it requires state.
In this talk, Steve Buchanan will take you through a journey of understanding how storage works in Kubernetes, how to Persistent state with pods, what storage options are available with Azure Kubernetes Service, best practices, and a demo of deploying a stateful app to AKS.
In the demo, I will show how to deploy stateful Worpress & Jenkins workloads on Azure Kubernetes Service using the GitOps model with Argo CD.
KEY TAKE-AWAYS FROM THE TALK
Overview of Storage in Kubernetes covering Storage Classes, Persistent Volumes, & Persistent Volume Claims. Overview of Azure Storage, Best Practices to running stateful apps in Kubernetes.
This was a fun podcast with Jez Ward, and Dave Chapman of Cloudreach. They run a podcast called Cloudbusting. On the podcast they focus on transformation, leadership, ways of working and emerging technology they explore the significant impact that cloud is having on people and businesses.
On this podcast episode, we set out to answer very important questions such as what are Jucy Lucy’s?, what are root Canals like today? oh, and yeah we also spend some time talking about what Containers, Kubernetes, & GitOps are and how they fit in the cloud.
With the growth of Kubernetes, the complexity & needs have also grown. IT Professionals need help with the operational & security challenges of managing Kubernetes clusters across multiple clouds, on-premises, & the edge.
My new course will teach you how to use Rancher for multi-Kubernetes cluster management, streamlining Kubernetes cluster deployments, & unified multi-Kubernetes cluster app management. When you’re finished with this course, you’ll have the skills and knowledge of Rancher needed for multi-K8s cluster management.
There is a learning path on Pluralsight focused on Kubernetes management. This is my 3rd course in the Kubernetes Management pathtitled “Kubernetes Tooling and Techniques” on Pluralsight. My other courses in the path are: “GitOps: The Big Picture” and “Getting Started with Argo CD“. You can get to the path using this link: https://app.pluralsight.com/paths/skills/kubernetes-tooling-and-techniques
I hope you find value in this new Getting Started with Rancher course. Be sure to follow my profile on Pluralsight so you will be notified as I release new courses related to Kubernetes and other topics!
Argo CD is a GitOps operator and the goal of it is to be able to deploy apps to Kubernetes. In the majority of cases, we want to use Argo CD to deploy apps to many clusters.
Argo CD itself is deployed as a set of pods on a Kubernetes cluster. By default with an Argo CD deployment, the cluster it is running on is set as “in-cluster” (https://kubernetes.default.svc). When apps are configured for deployment a Kubernetes Cluster under Destination is required. They can be deployed to either the “in-cluster” K8s cluster or an external K8s cluster.
In order to deploy apps to an external Kubernetes cluster, you will need to register an external K8s cluster with Argo CD.
If you want to see the clusters you have registered with your Argo CD one way is through the web UI. Once you log in navigate to Settings and then Clusters to see them.
You can also see the clusters you have in the Argo CD CLI. To use the Argo CD CLI you need to log into the Argo CD API Server as shown in the following screenshot.
To see what clusters are registered from the CLI you can run
argocd cluster list
You will notice that you will only see the In-Cluster K8s cluster until you add an external one. Also, note that you are not able to register a new K8 cluster in the Argo CD web UI. You can only register a new K8s cluster from the Argo CD CLI. Within the Argo CD web UI you can delete the default in-cluster K8s cluster. This is not recommended.
If you click on the In-Cluster K8s cluster you can modify some settings of the in-cluster K8s cluster in the Argo CD web UI such as the name of it and its namespace. Not useful when you want to have more control over the settings around the K8s cluster you will be deploying apps to.
In my example, my Azure subscription has two AKS clusters. You can see this in the following screenshot. The arriving-gelding-k8s cluster is my In-Cluster object in Argo CD. The selected-worm-k8s is not my In-Cluster so I want to add this one to my Argo CD.
To add the new external cluster run use the following steps.
Step 1: Add your target K8s cluster to ArgoCD via the context in your kubectl config.
-For AKS you can simply log into your Azure subscription from VS Code on your computer and then run
az aks get-credentials –resource-group RGNAME –name AKSCLUSTERNAME
This will add the context for your AKS cluster to your kubeconfig file.
In my last post on Argo CD with AKS, I mentioned the next post would explore deploying an app via Argo CD. Well, in this post we are going to do just that. I am going to walk through deploying an app from Argo CD to AKS. Note this same process would work for any Kubernetes cluster. This is not going to be a long post as the process is straightforward.
First of all, you can deploy an app from the Argo CD web UI or CLI. Ready your application in a Git-based repository. It does not matter what source control system you use for your repository as long as it is Git-based. You can use Azure DevOps, Gitlab, Bit Bucket etc. In my case I use GitHub. To deploy an app you need to point to a Git repository of either K8s manifest, Helm, or Kustomize. In this blog post I am going to keep it simple and use the Hello K8s app from Paul Bouwer. Ok, now let’s jump in.
Here are the steps for Deploying an App to Argo CD within the Web UI:
In the Argo CD web UI ensure you are on the Applications page
Click the + NEW APP button
Give the app the namehellok8s, use the project default (I used a dev project in my example), select Automatic for the sync policy, check AUTO-CREATE NAMESPACE