An app modernization story — Part 3 (Containerize & Redeploy)

In part 1, I talked about the initial app and its challenges. In part 2, I talked about the lift & shift to the cloud with some unexpected benefits. In this part 3 of the series, I’ll talk about how we transformed our Windows-only .NET Framework app to a containerized multi-platform .NET Core app and the huge benefits we got along the way. Why? The initial Windows VM based cloud setup served us well with minimal issues about roughly 2 years (from early 2017 to early 2019). [Read More]

An app modernization story — Part 2 (Lift & Shift)

In part 1 of app modernization series, I introduced a simple news aggregator and some of the challenges in its initial architecture. In part 2, I’ll talk about the journey to the cloud and some unexpected benefits and learnings along the way. Why Cloud? The initial backend had many issues that I outlined in part 1. After about 1 year, in late 2016, we decided to look into moving it to a more stable home. [Read More]

An app modernization story — Part 1 (Prototype)

We all have apps running some “legacy code” in some “legacy way”. The term “legacy” means different things in different projects but we know when we see it and we want to get the time to modernize those apps in some way. I recently went through the latest phase of modernization of a legacy app. Even though it’s a relatively small app, it thought me a number of lessons that’s worth sharing. [Read More]

Knative v0.12.0 update

It’s hard to keep with Knative releases with a release every 6 weeks. I finally managed to update my Knative Tutorial for the latest Knative v0.12.0. In this blog post, I want to outline some of the differences I’ve observed. Knative Serving Knative Serving has been pretty stable in the recent releases and Knative Serving v0.12.0 is no exception. I didn’t need to update my tutorial specifically for this release. [Read More]

How to properly install Knative on GKE

The default Knative Installation instructions for Google Kubernete Engine (GKE) is problematic (see bug 2266). In this post, I want to outline what the problem is, tell you what I do, and also provide you the scripts that work for me until a proper solution is implemented either in gcloud or Knative. The problem The default Knative Installation instructions tell you to create a GKE cluster as follows: gcloud beta container clusters create $CLUSTER_NAME \ --addons=HorizontalPodAutoscaling,HttpLoadBalancing,Istio \ --machine-type=n1-standard-4 \ --cluster-version=latest --zone=$CLUSTER_ZONE \ --enable-stackdriver-kubernetes --enable-ip-alias \ --enable-autoscaling --min-nodes=1 --max-nodes=10 \ --enable-autorepair \ --scopes cloud-platform Notice the Istio add-on. [Read More]

Cluster local issue with Knative Eventing v0.9.0

In my previous post, I talked about Knative v0.9.0 and some of the eventing changes in the latest release. I’ve been playing with Knative v0.9.0 since then to read Google Cloud Pub/Sub messages using PullSubscription and I ran into a rather fundamental issue that baffled me for a while. I’d like to outline the problem and the solution here, just in case it’s useful to others. Knative Services as eventing sinks In my PullSubscription, I could define Kubernetes Services as event sinks as follows: [Read More]

Knative v0.9.0

Knative has been evolving pretty quickly. There’s a new release roughly every 6 weeks with significant changes in each release. Knative v0.7.0 was all about changes in Knative Serving (my post). Knative v0.8.0 was about deprecation of Knative Build in favor of Tekton Pipelines (my other post). Knative Serving v0.9.0 and Eventing v0.9.0 have been released a little over a week ago. In Serving, there’s a v1 API and a number of improvements on autoscaling and cold starts. [Read More]

Migrating from Knative Build to Tekton Pipelines

Knative 0.8.0 and Build Deprecation Knative 0.8.0 came out a couple of weeks ago with a number of fixes and improvements. One of the biggest changes in 0.8.0 is that Knative Build is now deprecated according to docs: Knative Installation docs also only include Knative Serving and Eventing without mentioning Build: kubectl apply \-f https://github.com/knative/serving/releases/download/v0.8.0/serving.yaml \\ \-f https://github.com/knative/eventing/releases/download/v0.8.0/release.yaml \\ \-f https://github.com/knative/serving/releases/download/v0.8.0/monitoring.yaml Good to know but there’s no explanation on why Knative Build was deprecated and any guidance on what is the replacement, if any. [Read More]

Migrating from Kubernetes Deployment to Knative Serving

When I talk about Knative, I often get questions on how to migrate an app from Kubernetes Deployment (sometimes with Istio) to Knative and what are the differences between the two setups. First of all, everything you can do with a Knative Service, you can probably do with a pure Kubernetes + Istio setup and the right configuration. However, it’ll be much harder to get right. The whole point of Knative is to simplify and abstract away the details of Kubernetes and Istio for you. [Read More]

Serverless gRPC + ASP.NET Core with Knative

I was recently going through the ASP.NET Core updates in .NET Core 3.0 Preview 3 post, this section got my attention: gRPC template. Apparently, .NET Core 3.0 got a new gRPC template for easily building gRPC services with ASP.NET Core. I tested gRPC and .NET before and I have some samples in my grpc-samples-dotnet repo. Even though gRPC and .NET worked before, it wasn’t that straightforward to setup. I was curious to try out the new gRPC template and see how it helped. [Read More]