Tag Archives: K8s

Road to Kubernetes – MEAP book review

22 Thursday Jun 2023

Posted by in Book Reviews, Books, General, Technology

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One of the benefits of being a Manning author is that we get access to the Manning book catalog, including those currently in the MEAP early access programme (MEAP). The Road to Kubernetes title was bought to my attention. The book has just become available as a MEAP title; this means that the book has just completed its first major review milestone, and about a third of the book has been written. It does mean our review only covers the first 3 chapters at the moment.

What got my attention with this book is that unlike other titles about Kubernetes \9of which there are a number of great titles in the Manning portfolio already) is that it has adopted a different approach.

Most books focus on one technology and deep dive into that technology and dig into the more advanced features of that specific area. For an experienced IT person, that is great. But, when it comes to Kubernetes, if you’re skills are largely just focused on largely coding with languages like Java, Python, and JavaScript – not unusual for a graduate or junior developers it means the amount of reading and learning curve to get to grips with developing and deploying containers to Kubernetes is considerable. Here, Justin has taken the approach of assuming basic development skills and then taking you on a journey of focussing on the basics of containers, deployment automation, and then Kubernetes with just enough to be able to deploy a simple solution using good practices. This makes the learning path to gaining the skills that allow you to work within a team and building containerized solutions a lot easier.

I imagine once the book is complete and you’ve followed it through, you’ll be in a position to focus on learning new, more advanced aspects of containers and Kubernetes in a focused manner to meet the needs of a day-to-day job.

Having coached and mentored junior developers and graduates, this is a book I’d recommend to help them along, and if my experience with the Manning book development process is anything to go by, as Justin goes through the major milestones, this book will go from good to great.

My only word of caution is that this book will take the reader on a journey of building and deploying microservices to Kubernetes. Don’t be fooled into thinking Kubernetes and microservices are easy – there is a lot of technologies that I don’t think the book will go into (but then not all developers need to understand details such the differences in network fabric (Calico, Flannel) or container engines cri-o, Docker Engine, deploying support tooling for things like observability). Without good design and, depending upon your solution, a handle in a variety of more specialized areas, it is still possible to get yourself into a mess, even for the most experienced of teams.

OpenLens or Lens app

17 Monday Apr 2023

Posted by in Cloud Native, development, General, Technology

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I wrote about how much I like the lens app K8s dashboard capability without needing to deploy K8s dashboard. Sadly recently, there has been some divergence from K8sLens being a pure open source to a licensed tool with an upstream open-source version called Open Lens (article here). It has fallen to individual contributors to maintain the open-lens binary (here) and made it available via Chocolatey and Brew. The downside is that one of the nice features of K8sLens has been removed – the ability to look at container logs. If you read the Git repo issue on this matter – you’ll see that a lot of people are not very happy about this.

If you read through all the commentary on the ticket, you’ll eventually find the following part of the post that describes how the feature can be reintroduced.

In short, if you use the extensions feature and provide the URL of the extension as @alebcay/openlens-node-pod-menu then the option will be reintroduced. The access to the extension is here:

The details …

The extension identified is detailed here.

I’m not sure why, but I did find the installation a little unstable, and needed to reinstall the plugin, restart OpenLens and reenable the plugin. But once we got past that, as you can see below the plugin delivered on its promise.

The problem with the licensing is that it doesn’t distinguish between me as an individual and using Lens for my own personal use vs. using Lens for commercial activities. The condition sets out:

ELIGIBILITY:You or your company have less than $10M in annual revenue or funding.

https://app.k8slens.dev/subscribe

Given this wording, I can’t use the licensed version, even if I was working on an open-source project and in a personal capacity, as the company I’m employed by has more than $10 million in revenue. For me, the issue is $200 per year is a lot for something I only need to use intermittently. While I get k8slens includes additional features such as Lens Security which performs vulnerability management, and Lens Teamwork, along with support, are features and services that are oriented to commercial use – these are features I don’t actually want or need. Lens Kubernetes sounds like an interesting proposition (a built-in distribution of K8s), but when many others already provide this freely – from Docker Desktop to Kind it seems rather limited in value.

We did try installing Komodor, given its claims for an always free edition. But on my Windows 11 Pro (developer early access) installation, it failed to install, as you can see:

K8s dashboard capability without needing to deploy K8s dashboard

14 Tuesday Jun 2022

Posted by in Cloud Native, General, Technology

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Let’s be honest we’re not all command line warriors when it comes to Kubernetes. I can get around Kubectl but the time it takes to key in a CLI command you can get the same information in a couple of clicks of the UI. For me, Kubectl is for automating my tasks, for example pushing a local build into a image repository, initiating a refresh deployment and ensuring old container instances are flushed out.

Lens view
K8s Dashboard

The only problem is that the K8s dashboard requires a lot of config work to secure its deployment, and do you want to be deploying such tools in a production environment? A colleague suggested I look at Lens. A tool that offers both Personal (free) and Team licensed versions and both versions deploy to Windows, Linux, and Mac natively so installation doesn’t require any messing around.

I have to say I have been very impressed with Lens. Everything useful about the K8s dashboard is here, but without needing to deploy anything to your cluster as lens runs as a local thick app. Just like the K8s dashboard you need the privileges to talk to the K8s APIs. But the Visualization is all local and the way the data is retrieved means the UI is very reactive.

Read more: K8s dashboard capability without needing to deploy K8s dashboard

Lens supports extensions, although to date I’ve not tried any of the extensions personally – you can see a list of extensions here. I will be trying out a couple Of extensions in due course. For example:

Network Policy Viewer
Certificate Info (via K8s secrets)

Lens goes further by the fact you can connect to multiple clusters from a single viewer instance. So no need for multiple deployments of the dashboard or creating an additional management cluster.

I only have one minor grumble today with the implementation. When using a console facility to access a container it is not possible to paste into the console any text/script or copy out any of the log contents. The latter can make generating things like JIRA tickets a bit annoying. So far I’ve worked around it by creating screenshots.

Useful Resources

Kubernetes Deployment – pulling from OCI Registry (OCIR)

26 Thursday May 2022

Posted by in APIs & microservices, Cloud Native, General, Oracle, Oracle Cloud Native, Technology

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The following isn’t unique to OCIR, as it will hold true for any K8s Deployment YAML configuration that works with an Open Container Initiative compliant registry. To define the containers part of the YAML file we need to provide an attribute that can be used to confirm the legitimacy of the request. To do this we need to supply a token. However, we don’t want this token to be visible in plain sight in our YAML. The solution to this is to set up a secret within Kubernetes.

In the following YAML extract, we can see the secret is named.

kind: Deployment
metadata:
  name: graph-svr-deploy
  labels:
    app: arch-oke-graphql
spec:
  replicas: 1
  selector:
    matchLabels:
      app: arch-oke-graphql
  template:
    metadata:
      name: graph-svr-deploy
      labels:
        app: arch-oke-graphql
    spec:
      containers:
      - name: graphql-svr
        image: iad.ocir.io/ociobenablement/graphql-svr:latest 
        ports:
        - containerPort: 4000    
          name: graph-svr-web
      imagePullSecrets:
      - name: ocirsecret

This does mean we need to create the secret. As this is a one-off task the easiest step is to create the secret by hand. To do that we use the command:

@kubectl create secret docker-registry ocirsecret --docker-server=iad.ocir.io --docker-username=ociobenablement/identitycloudservice/philip.wilkins@oracle.com --docker-password='xxxxxxxx' --docker-email=philip.wilkins@oracle.com

This naturally leads to the next question where do we get the secret?

This step is straightforward. Navigating using the user icon top right (highlighted in the screenshot below), select the User Settings option to get to the screen shown below. Then use the right-hand menu option highlight (Auth Tokens). This displays a section of the UI showing your current auth tokens and provides a button that will popup a window to guide you through creating a new auth token.

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Istio In Action

25 Friday Mar 2022

Posted by in Book Reviews, Books, General, manning

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Christian Posta and Rinor Maloku’s book with Manning, Istio In Action has just been published. I’ve previously said it’s a good book, and that’s not surprising given Christian’s role at solo.io. When the final chapters became available I started to go through it in more detail and built a mind map (As with the recent review of Kubernetes best practices). The map can be seen below.

As you can see the map is very substantial reflecting on the depth and value of the book. For those who look at the maps, may notice there are a couple of chapters not fully mapped. I will update the map to fill those gaps in, but given they focus on monitoring and observability, I was less concerned about those areas given my own writing. The book’s exercises are very much built around using Docker Desktop making it very easy to spin up the examples and exercises. If you want to know about Istio Service Mesh on K8s then I’d recommend it.

Reading through the book, I’ve learned details that I was not entirely aware of, for example the integration of non K8s workloads into the mesh. The tuning of Istio to keep it highly performant with a lot of workloads.

The book can be obtained from:

And other retailers of course.