Kubernetes on Samarthya

ServiceAccount

Wed, 16 Feb 2022 12:00:00 +0000

If you have seen errors like these when deploying using a serviceAccount

Error: INSTALLATION FAILED: rendered manifests contain a resource that already exists. Unable to continue with install: could not get information about the resource ConfigMap "spinnaker-hellow-pipline" in namespace "spinnaker": configmaps "spinnaker-hellow-pipline" is forbidden: User "system:serviceaccount:jenkins:default" cannot get resource "configmaps" in API group "" in the namespace "spinnaker"

What?
#

A service account provides an identity for processes that run in a Pod.
Every namespace has a default service account
When you create a pod, if you do not specify a service account, it is automatically assigned the default service account in the same namespace.
To use a non-default service account, set the spec.serviceAccountName field of a pod to the name of the service account you wish to use.
The service account has to exist at the time the pod is created, or it will be rejected.
The service account of an already created pod cannot be updated

Default RBAC policies grant scoped permissions to control-plane components, nodes, and controllers, but grant no permissions to service accounts outside the kube-system namespace (beyond discovery permissions given to all authenticated users). — Official documentation

Example
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apiVersion: v1
kind: ServiceAccount
metadata:
 creationTimestamp: "2021-08-27T07:52:20Z"
 name: default
 namespace: default
 resourceVersion: "XXXX"
 uid: XXXX
secrets:
- name: default-token-vcb75

Let’s add docker-registry secret to the SA. (My secret name is samarthya-docker)

`Devspace`: Managing Apps in Kubernetes

Tue, 15 Feb 2022 12:00:00 +0000

What is `devspace`?
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devspace is a CLI tool for kubernetes, which can help you configure, deploy, debug. and test your application inside Kubernetes.

Kaniko: Jenkins Pipeline

Fri, 11 Feb 2022 12:00:00 +0000

So there are many things I have been simultaneously trying to learn & one of those is to learn how you can configure a pipeline

Objectives
#

Learn Jenkins deployment on Kubernetes
Learn Jenkins Kubernetes Plugin
Learn Jenkins Pipeline (Declarative)
How to build and deploy images in Kubernetes cluster

All right, with so many monkeys on my back I had to do things the way I know it works for me.

Kafka: Deploy & Test

Fri, 11 Feb 2022 08:17:19 +0000

While I continue to learn more about architecture and design of kafka, a quickstart to deploy & test kafka is a must.

Step 1: Add Chart Repo
#

In my local system it is already present which was confirmed by the listing

Spinnaker: Open Source Deployment

Sat, 05 Feb 2022 12:00:00 +0000

I have written a series of blogs to capture how you can deploy spinnaker on a Kubernetes cluster & manage a helm chart deployment via pipeline.

The only way to enable more frequent changes is to invest in supporting people with better tooling, practices, and culture

From the Book Spinnaker

Jenkins: K8S

Wed, 02 Feb 2022 12:00:00 +0000

Deploying Jenkins on K8S cluster is as simple as

Add Repo
#

helm repo add jenkins https://charts.jenkins.io
helm repo update

Deploy instance

Adding Node to a cluster

Thu, 06 Jan 2022 06:58:31 +0000

In this blog, I will try add a new node to the already running cluster.

My Cluster
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root@master>k get nodes
NAME STATUS ROLES AGE VERSION
mydevmachine001830.samarthya.me Ready <none> 22h v1.23.1
mydevmachine002687.samarthya.me Ready <none> 41d v1.23.1
mydevmachine003277.samarthya.me Ready <none> 131d v1.23.1
mydevmachine003278.samarthya.me Ready <none> 131d v1.23.1
mydevmachine003417.samarthya.me Ready <none> 4m55s v1.23.1
mydevmachine003968.samarthya.me Ready <none> 131d v1.23.1
mydevmachine003969.samarthya.me Ready control-plane,master 131d v1.23.1
mydevmachine003970.samarthya.me Ready <none> 131d v1.23.1
mydevmachine003979.samarthya.me Ready <none> 29m v1.23.1

Steps to follow
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Install docker
Install kubeadm, kubectl & kubelet
Join the cluster using the token
Check the node has joined the cluster

Step 1: Install docker
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sudo yum install -y yum-utils
sudo yum-config-manager \
 --add-repo \
 https://download.docker.com/linux/centos/docker-ce.repo

When adding repo make sure the repo has been added successfully to the machine

Upgrading K8S cluster

Wed, 05 Jan 2022 07:05:30 +0000

In this blog I will talk about how you can upgrade a node and the kubernetes cluster version to a specific version.

I have a 6 node local Kubernetes cluster like below

K8S RBAC

Mon, 13 Dec 2021 13:03:56 +0000

What?
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Role Based Access Control(s) is a way of regulating access to entities like storage, network etc.
RBAC authorization uses rbac.authorization.k8s.io API group.

API Objects
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There are 4 kind of kubernetes object

CALICO CNI failures

Thu, 28 Oct 2021 07:46:58 +0000

In my cluster things went haywire all of a sudden without a proper showcase, I tried multiple things but it was just not working. Specifically my core-dns and calico-kube-controllers were not coming up and were constantly showing not ready and CrashLoop respectively

Kubernetes on Samarthya

ServiceAccount

What? #

Example #

`Devspace`: Managing Apps in Kubernetes

What is devspace? #

Kaniko: Jenkins Pipeline

Objectives #

Kafka: Deploy & Test

Step 1: Add Chart Repo #

Spinnaker: Open Source Deployment

Jenkins: K8S

Add Repo #

Adding Node to a cluster

My Cluster #

Steps to follow #

Step 1: Install docker #

Upgrading K8S cluster

K8S RBAC

What? #

API Objects #

CALICO CNI failures

What?
#

Example
#

What is `devspace`?
#

Objectives
#

Step 1: Add Chart Repo
#

Add Repo
#

My Cluster
#

Steps to follow
#

Step 1: Install docker
#

What?
#

API Objects
#