Technical on Samarthya

ClusterRole: Refresher

Tue, 06 Apr 2021 11:26:35 +0000

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

SAFe for Lean enterprises

Mon, 01 Mar 2021 16:14:46 +0000

SAFe is a framework; one of the leading, for business agility that allows an organization to adapt based on its own business needs. It mixes the best of Agile, Lean, DevOps into an exhaustive system of guidelines to deliver quality, innovative products in a more predictive manner.

Fun with `goroutines`

Fri, 26 Feb 2021 08:36:20 +0000

Channels are way of communication between multiple goroutines

You can declare a channel and the type of content the channel will receive like below.

var myChannel chan int

The int above is the type of data it can receive and the data can be send using

Missed Opportunity

Mon, 25 Jan 2021 13:17:28 +0000

The new year did not begin on a note I would have expected, I missed out on a golden opportunity. It would have been a wonderful exposure had it sailed through, but as someone famously said

DevBhoomi: Uttarkhand

Thu, 07 Jan 2021 05:48:24 +0000

Business Agility

Sun, 20 Sep 2020 10:03:52 +0000

Update
#

A dull Saturday, lazy morning and unfortunately the next door neighbor is down thanks to COVID-19. Hopefully he should recover just fine but till then we are also forced to be Home quarantined.

Elastic 7.5

Mon, 06 Jan 2020 00:00:00 +0000

Installing
#

Step 1: Using docker
#

yum install docker
docker pull docker.elastic.co/elasticsearch/elasticsearch:7.5.1

systemctl list-units --type=service

docker version
Client:
 Version: 1.13.1
 API version: 1.26
 Package version:

Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

sudo systemctl start docker

docker version
Client:
 Version: 1.13.1
 API version: 1.26
 Package version: docker-1.13.1-103.git7f2769b.el7.centos.x86_64
 Go version: go1.10.3
 Git commit: 7f2769b/1.13.1
 Built: Sun Sep 15 14:06:47 2019
 OS/Arch: linux/amd64

Server:
 Version: 1.13.1
 API version: 1.26 (minimum version 1.12)
 Package version: docker-1.13.1-103.git7f2769b.el7.centos.x86_64
 Go version: go1.10.3
 Git commit: 7f2769b/1.13.1
 Built: Sun Sep 15 14:06:47 2019
 OS/Arch: linux/amd64
 Experimental: false

docker pull docker.elastic.co/elasticsearch/elasticsearch:7.5.1
Trying to pull repository docker.elastic.co/elasticsearch/elasticsearch ... 
7.5.1: Pulling from docker.elastic.co/elasticsearch/elasticsearch
c808caf183b6: Pull complete 
05ff3f896999: Pull complete 
82fb7fb0a94e: Pull complete 
c4d0024708f4: Pull complete 
136650a16cfe: Pull complete 
968db096c092: Pull complete 
42547e91692f: Pull complete 
Digest: sha256:b0960105e830085acbb1f9c8001f58626506ce118f33816ea5d38c772bfc7e6c
Status: Downloaded newer image for docker.elastic.co/elasticsearch/elasticsearch:7.5.1

docker pull docker.elastic.co/kibana/kibana:7.5.1

KubeLab

Thu, 10 Oct 2019 00:00:00 +0000

Kubernetes

cloud_user@ip-10-0-1-101:~$ kubectl version
Client Version: version.Info{Major:"1", Minor:"13", GitVersion:"v1.13.3", GitCommit:"721bfa751924da8d1680787490c54b9179b1fed0", GitTreeState:"clean", BuildDate:"2019-02-01T20:08:12Z", GoVersion:"go1.11.5", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"13", GitVersion:"v1.13.11", GitCommit:"25074a190ef2a07d8b0ed38734f2cb373edfb868", GitTreeState:"clean", BuildDate:"2019-09-18T14:34:46Z", GoVersion:"go1.11.13", Compiler:"gc", Platform:"linux/amd64"}

cloud_user@ip-10-0-1-101:~$ kubectl api-resources
NAME SHORTNAMES APIGROUP NAMESPACED KIND
bindings true Binding
componentstatuses cs false ComponentStatus
configmaps cm true ConfigMap
endpoints ep true Endpoints
events ev true Event
limitranges limits true LimitRange
namespaces ns false Namespace
nodes no false Node
persistentvolumeclaims pvc true PersistentVolumeClaim
persistentvolumes pv false PersistentVolume
pods po true Pod
podtemplates true PodTemplate
replicationcontrollers rc true ReplicationController
resourcequotas quota true ResourceQuota
secrets true Secret
serviceaccounts sa true ServiceAccount
services svc true Service
mutatingwebhookconfigurations admissionregistration.k8s.io false MutatingWebhookConfiguration
validatingwebhookconfigurations admissionregistration.k8s.io false ValidatingWebhookConfiguration
customresourcedefinitions crd,crds apiextensions.k8s.io false CustomResourceDefinition
apiservices apiregistration.k8s.io false APIService
controllerrevisions apps true ControllerRevision
daemonsets ds apps true DaemonSet
deployments deploy apps true Deployment
replicasets rs apps true ReplicaSet
statefulsets sts apps true StatefulSet
tokenreviews authentication.k8s.io false TokenReview
localsubjectaccessreviews authorization.k8s.io true LocalSubjectAccessReview
selfsubjectaccessreviews authorization.k8s.io false SelfSubjectAccessReview
selfsubjectrulesreviews authorization.k8s.io false SelfSubjectRulesReview
subjectaccessreviews authorization.k8s.io false SubjectAccessReview
horizontalpodautoscalers hpa autoscaling true HorizontalPodAutoscaler
cronjobs cj batch true CronJob
jobs batch true Job
certificatesigningrequests csr certificates.k8s.io false CertificateSigningRequest
leases coordination.k8s.io true Lease
events ev events.k8s.io true Event
daemonsets ds extensions true DaemonSet
deployments deploy extensions true Deployment
ingresses ing extensions true Ingress
networkpolicies netpol extensions true NetworkPolicy
podsecuritypolicies psp extensions false PodSecurityPolicy
replicasets rs extensions true ReplicaSet
networkpolicies netpol networking.k8s.io true NetworkPolicy
poddisruptionbudgets pdb policy true PodDisruptionBudget
podsecuritypolicies psp policy false PodSecurityPolicy
clusterrolebindings rbac.authorization.k8s.io false ClusterRoleBinding
clusterroles rbac.authorization.k8s.io false ClusterRole
rolebindings rbac.authorization.k8s.io true RoleBinding
roles rbac.authorization.k8s.io true Role
priorityclasses pc scheduling.k8s.io false PriorityClass
storageclasses sc storage.k8s.io false StorageClass
volumeattachments storage.k8s.io false VolumeAttachment

cloud_user@ip-10-0-1-101:~$ kubectl get cm
NAME DATA AGE
fruit-service-ambassador-config 1 5m49s

Basic Commands (Beginner):
 create Create a resource from a file or from stdin.
 expose Take a replication controller, service, deployment or pod and expose it as a new Kubernetes Service
 run Run a particular image on the cluster
 set Set specific features on objects

Basic Commands (Intermediate):
 explain Documentation of resources
 get Display one or many resources
 edit Edit a resource on the server
 delete Delete resources by filenames, stdin, resources and names, or by resources and label selector

Deploy Commands:
 rollout Manage the rollout of a resource
 scale Set a new size for a Deployment, ReplicaSet, Replication Controller, or Job
 autoscale Auto-scale a Deployment, ReplicaSet, or ReplicationController

Cluster Management Commands:
 certificate Modify certificate resources.
 cluster-info Display cluster info
 top Display Resource (CPU/Memory/Storage) usage.
 cordon Mark node as unschedulable
 uncordon Mark node as schedulable
 drain Drain node in preparation for maintenance
 taint Update the taints on one or more nodes

Troubleshooting and Debugging Commands:
 describe Show details of a specific resource or group of resources
 logs Print the logs for a container in a pod
 attach Attach to a running container
 exec Execute a command in a container
 port-forward Forward one or more local ports to a pod
 proxy Run a proxy to the Kubernetes API server
 cp Copy files and directories to and from containers.
 auth Inspect authorization

Advanced Commands:
 diff Diff live version against would-be applied version
 apply Apply a configuration to a resource by filename or stdin
 patch Update field(s) of a resource using strategic merge patch
 replace Replace a resource by filename or stdin
 wait Experimental: Wait for a specific condition on one or many resources.
 convert Convert config files between different API versions

Settings Commands:
 label Update the labels on a resource
 annotate Update the annotations on a resource
 completion Output shell completion code for the specified shell (bash or zsh)

Other Commands:
 api-resources Print the supported API resources on the server
 api-versions Print the supported API versions on the server, in the form of "group/version"
 config Modify kubeconfig files
 plugin Provides utilities for interacting with plugins.
 version Print the client and server version information

Usage:
 kubectl [flags] [options]

Vue - Lesson 2

Fri, 01 Mar 2019 00:00:00 +0000

Zero configuration

CLI command line interface

Create things rapidly

select libraries you want to use

Optimize the loading speed

CHoose your own adventure

Starting from a blank state

organizing the structure.

Learning Step - 1

Wed, 27 Feb 2019 00:00:00 +0000

The best way to learn a technology is to create something from scratch and as my ever wandering brain hops from one framework to another I am starting out on a new conquest of learning something that professionally I have never tried. Not just a scripting technology but learning the new enabler platforms as well.