Setup Kubernetes Cluster using kubeadm, calico and rbac in Ubuntu
Prerequisite Setup Master Node Setup aka Kubernetes Control Panel Setup Worker Node Setup Rajesh KumarI’m a DevOps/SRE/DevSecOps/Cloud Expert passionate about sharing knowledge and experiences. I have worked…
Create Google Kubernetes Engine(GKE) Cluster using command line
Rajesh KumarI’m a DevOps/SRE/DevSecOps/Cloud Expert passionate about sharing knowledge and experiences. I have worked at Cotocus. I share tech blog at DevOps School, travel stories at Holiday…
Create Azure kubernetes Clustors(AKS) using command line
Rajesh KumarI’m a DevOps/SRE/DevSecOps/Cloud Expert passionate about sharing knowledge and experiences. I have worked at Cotocus. I share tech blog at DevOps School, travel stories at Holiday…
Kubernetes volume hostPath explained with examples
The hostPath volume mounts a resource from the host node filesystem. the resources could be directory, file socket, character, or block device. These resources mu A hostPath…
Kubernetes volume emptyDir explained with examples
Here are the following facts for emptyDir storage type in Kubernetes An emptyDir volume is first created when a Pod is assigned to a Node and initially…
Working with multiple virtual Kubernetes clusters aka Namespaces
Kubernetes supports multiple virtual clusters backed by the same physical cluster. These virtual clusters are called namespaces. Namespaces ca be used in multiple environment with many users…
minikube error – VBoxManage.exe: error: DHCP server already exists
Error Message Solutions minikube stop minikube start Rajesh KumarI’m a DevOps/SRE/DevSecOps/Cloud Expert passionate about sharing knowledge and experiences. I have worked at Cotocus. I share tech blog…
minikube error – CrashLoopBackOff: secrets is forbidden: User “system:serviceaccount:kube-system:default”
$ minikube dashboard Temporary Error: unexpected response code: 503 Temporary Error: unexpected response code: 503 Temporary Error: unexpected response code: 503 Temporary Error: unexpected response code: 503…
How to check Containers readiness inside a pod using readinessProbe?
A Probe is a diagnostic performed periodically by the kubelet on a Container. To perform a diagnostic, the kubelet calls a Handler implemented by the Container. There…
How to check Containers health inside a kubernetes pod using livenessProbe?
A Probe is a diagnostic performed periodically by the kubelet on a Container. To perform a diagnostic, the kubelet calls a Handler implemented by the Container. There…
How to enable Elastic Search REST API Accessible using IP Address?
By default http transport and internal elasticsearch transport only listens to localhost. If you want to access Elasticsearch from the host other than localhost then try adding…
Ansible Playbook Lab & Excercise – Part 7
Create a playbook where you should install a webserver into 2 OS type(Ubuntu and RHEL) with fact conditioning. and list out a directory which in “/etc” and…
Ansible Windows Playbook Lab & Excercise – Part 8
Write a playbook to Create a dir, named with your-name inside C:\HPE and create a file named with “readme.txt” inside “C:\HPE\ and content of the file should…
Ansible Windows Adhoc Commands Lab & Excercise – Part 2
Write a Adhoc command to Create a dir, named with your-name inside C:\HPE and create a file named with “readme.txt” inside “C:\HPE\ and content of the file…
How to install Ansible in Centos 7/RHEL 7?
How to install Ansible in Centos 7/RHEL 7? Install Ansible via Pip in RHEL/CENTOS Rajesh KumarI’m a DevOps/SRE/DevSecOps/Cloud Expert passionate about sharing knowledge and experiences. I have…
Kibana 7.2 Install and configuration in RHEL 7/Centos
Install and Setup JDK 8+ Download and Install Kibana 7.X Configure Kibana 7.X How to start kibana service? Rajesh KumarI’m a DevOps/SRE/DevSecOps/Cloud Expert passionate about sharing knowledge…
How to use elastic search EC2 discovery plugin?
Problem To increase the performance in Elasticsearch, many times we add new nodes to Elasticsearch cluster and manually change the configuration file with new IP address, etc….
Elastic Search Error – Node is started with node.data=false, but has shard data
[2019-07-11T09:59:18,013][ERROR][o.e.b.Bootstrap ] [es-master01] Exception java.lang.IllegalStateException: Node is started with node.data=false, but has shard data: [/home/ec2-user/elasticsearch-7.2.0/data/nodes/0/indices/6XsNftnbSbOnzPK3wOKc 0w/0]. Use ‘elasticsearch-node repurpose’ tool to clean up at org.elasticsearch.env.NodeEnvironment.ensureNoShardData(NodeEnvironment.java:1065) ~[elasticsearch-7.2.0.jar:7.2.0] at…
Elastic Search Error – max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
Errors [2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144] Solution To make it persistent, you can add this line: $…
Elastic Search Error – max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]
Elastic Search Error – max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535] Solution Temporary to the current login session To…
How to create sample data to perform searches using elastic search?
Step 1 – Go to: http://www.json-generator.com/ Step 2 – Download and save as customers_full.json Step 3 – Open customers_full.json in sublimetext Remove the array brackets Find-Replace },{…
What is difference between application/x-ndjson and application/json?
Lets understand what is json? JSON stands for JavaScript Object Notation JSON is a lightweight format for storing and transporting data JSON is often used when data…
Elastic Search Error – The bulk request must be terminated by a newline
FIX – Add a New line in customers_full.json Rajesh KumarI’m a DevOps/SRE/DevSecOps/Cloud Expert passionate about sharing knowledge and experiences. I have worked at Cotocus. I share tech…
ElasticSearch Error – illegal_argument_exception – Rejecting mapping update to type
########### COMMAND ################# ########### OUTPUT ########### Solution Multiple mapping types are not supported in indices created in 6.0 The ability to have multiple mapping types per index…
ElasticSearch Error – Content-Type header [application/x-www-form-urlencoded] is not supported
To fix this, add curl option -H ‘Content-Type: application/json’. This error is due to strict content-type checking introduced in ElasticSearch 6.0 Solution Rajesh KumarI’m a DevOps/SRE/DevSecOps/Cloud Expert…
Understading Octopus Deploy Backup and restore process
Your Master Key When an Octopus Server is installed, we generate a special key used for encryption, called the master key. The master key is then encrypted…
Prevent direct download of photos/video files from amazon s3
You can restrict access based on the HTTP referrer. It’s not bulletproof (Referrer can be spoofed) but it will stop casual downloads. Suppose you have a website…
Ansible Include and Import with differences explanined!
This is one of the most frequest questions being asked in my workshop is that differences between using import or include in Ansible. For example import_role or…
Understanding Ansible Architecture using diagram
What is Ansible? Rajesh KumarI’m a DevOps/SRE/DevSecOps/Cloud Expert passionate about sharing knowledge and experiences. I have worked at Cotocus. I share tech blog at DevOps School, travel…
Order of operations during Ansible playbook parsing explained!
We will delve into some specifics of how a playbook is parsed for Order of operations. Ansible can be assumed to be executed in a top to…