Cloud DevOps Admin Guide

Running Commands as Another User via sudo

You want one user to run commands as another, without sharing passwords.
Suppose you want user smith to be able to run a given command as user jones.

               /etc/sudoers:
smith  ALL = (jones) /usr/local/bin/mycommand

User smith runs:

smith$ sudo -u jones /usr/local/bin/mycommand
smith$ sudo -u jones mycommand                     If /usr/local/bin is in $PATH

User smith will be prompted for his own password, not jones’s.
The ALL keyword, which matches anything, in this case specifies that the line is valid on any host.
sudo exists for this very reason!
To authorize root privileges for smith, replace “jones” with “root” in the above example.

Kubectl commands - Kubernetes

Kubectl is a command line interface for running commands against Kubernetes clusters. This overview covers kubectl syntax, describes the command operations, and provides common examples. For details about each command, including all the supported flags and subcommands, see the kubectl reference documentation.

List all services

kubectl get services 
kubectl get svc

List everything

kubectl get all --all-namespaces

Describe service <name>

kubectl describe svc <name>

Get services sorted by name

kubectl get services –sort-by=.metadata.name

List all pods

kubectl get pods

Watch nodes continuously

kubectl get pods -w

Get version information

kubectl get version

Get cluster information

kubectl get cluster-info

Get the configuration

kubectl config view

Output information about a node

kubectl describe node <node-name>

List the replication controllers

kubectl get rc

List the replication controllers in specific <namespace>

kubectl get rc -n <namespace-name>

Describe replication controller <name>

kubectl describe rc <name>

Delete pod <name>

kubectl delete pod <name>

Delete replication controller <name>

kubectl delete rc <name>

Delete service <name>

kubectl delete svc <name>

Remove <node> from the cluster

kubectl delete node <name>

Show metrics for nodes

kubectl top nodes

Show metrics for pods

kubectl top pods

Watch the Kublet logs

watch -n 2 cat /var/log/kublet.log

Get logs from service <name>, optionally selecting container <$container>

kubectl logs -f <name> [-c <$container>]

execute <command> on <service>, optionally selecting container <$container>

kubectl exec <service> <command> [-c <$container>]

Initialize your master node

kubeadm init

Join a node to your Kubernetes cluster

kubeadm join --token <token> <master-ip>:<master-port>

Create namespace <name>

kubectl create namespace <namespace>

Allow Kubernetes master nodes to run pods

kubectl taint nodes --all node-role.kubernetes.io/master

Reset current state

kubeadm reset

List all secrets

kubectl get secrets

Launch a pod called <name> ,using image <image-name>

kubectl run <name> --image=<image-name>

Create a service described in <manifest.yaml> file

kubectl create -f <manifest.yaml>

Validate yaml file with dry run

kubectl create --dry-run --validate -f sysaix.yaml

Scale replication controller

kubectl scale rc <name> --replicas=<count>

Stop all pods on specific pods

kubectl drain <n> --delete-local-data --force --ignore-deamonsets

Explain resource

kubectl explain pods
kubectl explain svc

Open a bash terminal in a pod

kubectl exec -it sysa'xpod sh

Check pod environment variables

kubectl exec sysaixpod env

Filter pods by label

kubectl get pods -l owner=emre

List statefulset

kubectl get sts

Scale statefulset

kubectl scale sts <stateful_set_name> --replicas=5

Delete statefulset only (not pods)

kubectl delete sts <stateful_set_name> --cascade=false

View all events

kubectl get events --all-namespaces

How to enable Accelerated Networking on an existing VM - AZURE

First, not all VM size support Accelerated Network, the supported OS and VM size can be found here:

https://docs.microsoft.com/en-us/azure/virtual-network/create-vm-accelerated-networking-cli

https://docs.microsoft.com/en-us/azure/virtual-network/create-vm-accelerated-networking-powershell

so I’ve deallocate the VM and change the size to DS3 v2, that’s a supported VM size.

Then run the following PowerShell Commands

$nic = Get-AzureRmNetworkInterface -ResourceGroupName "bigvnetgroup" -Name "server2016344"

$nic.EnableAcceleratedNetworking = $true

$nic | Set-AzureRmNetworkInterface