Docker

Podman Machine is a tool that allows you to manage multiple Linux containers on your local system or on remote servers.

Buildah is a command-line tool used for building and managing OCI-compliant images. It is an alternative to Docker Build that provides greater flexibility and control over the image building process.

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

A common use-case for cert-manager is requesting TLS signed certificates to secure your ingress resources.

You will need a valid docker registry before you add any trigger in the pipeline in Spinnaker

So to delete there was one hard hack way of cleaning it all

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

In this blog I will use kubectl to create a ClusterRole and a ClusterRoleBinding (refer to link) { "kind": "ClusterRole", "apiVersion": "rbac.authorization.k8s.io/v1", "metadata": { "name": "myclusterrole", "creationTimestamp": null }, "rules": [ { "verbs": [ "get", "list", "watch" ], "apiGroups": [ "" ], "resources": [ "persistentvolumes" ] } ] } k create clusterrole myclusterrole --verb=get,list,watch --resource=persistentvolumes k describe clusterrole myclusterrole You can use a ClusterRole to define permissions on namespaced resources and be granted within individual namespace(s) define permissions on namespaced resources and be granted across all namespaces define permissions on cluster-scoped resources

Everything in the same file apiVersion: v1 kind: Pod metadata: name: redispod spec: containers: - image: redis name: redisdb volumeMounts: - name: redis-data mountPath: /data ports: - containerPort: 6379 protocol: TCP volumes: - name: redis-data persistentVolumeClaim: claimName: redisdb-pvc --- apiVersion: v1 kind: PersistentVolume metadata: name: redis-pv spec: storageClassName: "" capacity: storage: 1Gi accessModes: - ReadWriteOnce hostPath: path: "/mnt/data" --- apiVersion: v1 kind: PersistentVolumeClaim metadata: name: redisdb-pvc spec: storageClassName: "" accessModes: - ReadWriteOnce resources: requests: storage: 1Gi If you deploy you will get something like

Reference # https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/ https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/#example-use-cases Before we understand the tainting we should know about the Node Affinity. It the by the virtue of Affinity that pods attracts nodes as a preference or as a basic requirement.

A cheat sheet for Installing K8S cluster. Step1: # Check your OS? cat /etc/issue lsb_release -a Step 2: # Add the GPG key as described here

Step by step: installing Docker, kubeadm, kubelet and kubectl on Ubuntu 18.04, initialising the control plane and joining worker nodes.

For my local K8S cluster of 4 nodes I wanted to get the resource usage metrics. From the official documentation of kubernetes.io These metrics can be accessed either directly by the user with the kubectl top command, or by a controller in the cluster, for example Horizontal Pod Autoscaler, to make decisions. https://kubernetes.io

Someone asked me to define a simple docker pod for the service I wrote in GOLang here. I completely forgot about it, till today. So here is my first attempt at getting a docker image for the service.

Volumes are managed by Docker and is the preferred way of persisting, sharing data.

The storage driver allows your to create data in the writable layers of the container and it also controls how images and containers are stored and managed on the Docker host.

A Docker registry is a stateless, highly scalable server side application that stores and lets you distribute Docker images. Docker registry is a central location that stores and distributes docker images. E.g. hub.docker.com is the default registry used when you are using docker pull.