harivemula

SSH to TKG clusters in AWS EC2

Change the private key permission

chmod 400 aws-privkey.pem

Use the below command to get into a node via bastion host

ssh -o ProxyCommand='ssh -i <yourawsprivatekey.pem> -W %h:%p ubuntu@<bastion-host-ip>' -i <yourawsprivatekey.pem> ec2-user@<Node-IP>

You may create a ssh config for aliases

harivemula

Enable SSH in Ubuntu 18.04

Install openssh server if not already installed.

sudo apt update
sudo apt install openssh-server

Check the status of the openssh-server, it should show Active: active (Running)

harivemula

Creating a Helm Chart using helm3 for an application.

Install helm (version >3.x) cli, Follow the steps described in this link.

Run the below command to ensure the version.

$ helm version --short

Go to the directory where you would like to create the chart. Run the below command, which creates chart with pre-defined templates. Use the name of the chart as your application/module name.

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Mount New Disk to Ubuntu 18.04

• Check the attached disks by using below command, verify the space df -h

Filesystem      Size  Used Avail Use% Mounted on
udev            491M     0  491M   0% /dev
tmpfs           103M  771k  102M   1% /run
/dev/xvda1      8.3G  1.2G  7.1G  15% /
tmpfs           514M     0  514M   0% /dev/shm
tmpfs           5.3M     0  5.3M   0% /run/lock

harivemula

#!/bin/bash -e

# version: 1.0
# Generate kubeconfig file from service account token
# Usage ./k8s-sa-kubeconfig.sh <namespace>  <service account name>

TEMPDIR=$( mktemp -d )

trap "{ rm -rf $TEMPDIR ; exit 255; }" EXIT

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NOTE: don't use this method if you have alternate way to fix it by using any other user with clients.write scope

If you have removed uaa.admin scope from TKGi 'admin' user, here are the steps to fix it by db method

• bosh -d <pks...> ssh pks-db/0
• sudo su -
• mysql --socket=/var/vcap/sys/run/pxc-mysql/mysqld.sock -u uaa -p
• <password should be from TKGi tile 'Cf Mysql Uaa Db Password'>
• use uaa;

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# *Supervisor Cluster*
# Login to vCenter server and run the below command to retrieve the Supervisor cluster IP and password
/usr/lib/vmware-wcp/decryptK8Pwd.py
# Use the username as 'root' and password provided by above command to login to Supervisor node(s). 
#   IP returned by above commmand is VIP of cluster api servers.

ssh root@<supervisor-node-ip>


### *Guest Clusters*

harivemula

Handling Multiple Github Accounts on MacOS

The only way I've succeeded so far is to employ SSH.

Assuming you are new to this like me, first I'd like to share with you that your Mac has a SSH config file in a .ssh directory. The config file is where you draw relations of your SSH keys to each GitHub (or Bitbucket) account, and all your SSH keys generated are saved into .ssh directory by default. You can navigate to it by running cd ~/.ssh within your terminal, open the config file with any editor, and it should look something like this:

Host *
 AddKeysToAgent yes

> UseKeyChain yes

harivemula

## zsh

brew install ffmpeg

## If you have any spaces in file name, run below command to replace
# 
for FILE in *.mov; do mv "$FILE" `echo $FILE | tr ' ' '_'` ; done

## If you are running from a different directory, you may use ${FILE:t:r} to just keep the filename without path and extension

harivemula

Installing & Configuring 'cert-manager' on GKE cluster with Nginx ingres

Confirm before running the below for installing ingress (nginx)

• helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
• helm install quickstart ingress-nginx/ingress-nginx

Install a sample service

• kubectl apply -f https://netlify.cert-manager.io/docs/tutorials/acme/example/deployment.yaml
• kubectl apply -f https://netlify.cert-manager.io/docs/tutorials/acme/example/service.yaml