Azure, RPA, AI, Selenium, Angular, API
Jenkins jobs and Jenkins pipeline are essentially same, however pipeline is more staged flow of jobs. For Jenkins pipeline, Jenkinsfile is used.
What is Jenkinsfile?Jenkinsfile is a text file placed in the root project directory. The Jenkinsfile has multiple stages like build, unit test, sonar test, functional, regression, integration, performance testing, deployment etc.
Apache Kafka was built by LinkedIn initially and then offered to Apache Foundation. Development was done using Java and Scala.
Why Kafka is able to handle high volume transactions?
Kafka is meant to handle high volume fractions as the way it is architectured. Message key value pairs are called as “procedures” in Kafka. The data are “partition”ed with in Kafka “topics”
Messages are strictly indexed with timestamps.
What is Kafka brokers ?Kafka brokers are clusters of one more servers. Kafka Partitions of topics are distributed across clusters.
Kafka is more effective compared to Java messaging services (JMS) or Advanced message queuing protocol (AMQP).
Flagger works are controller of the deployment workflow and helps automating the promotion of canary deployments. It utilizes the Istio’s and Prometheus metrics for analyzing application behaviors.
What is Istio ?
Istio is an open source service mesh that allows you to connect, monitor, secure your microservices deployment on premises or in cloud or in Kubernetes orchestration platforms.
What is Prometheus?Prometheus tracks events and helps as an alerting software.
In short, docker daemon acts as a server and exposes APIs to Docker client CLI and other third parties consumers. Altogether docker architectured as a client server based implementation.
Let’s also understand the basics about how docker works
Docker is a platform which allows DevOps teams to package the applications and run in containers.
These docker containers talks directly to Operating system kernel to perform activities and keeps the applications and dependencies independently from machines. Docker container can even run on Virtual machines as well.
What is Kernel ?
Kernel is the core of any Operating system. Kernel has complete control on OS and connects hardware and softwares.
Ansible roles are used to break the Ansible playbooks into multiple files. Usually an Ansible developer may have a tendency to write large single playbooks that adds complexity and that is when Ansible roles would come into real help.
Ansible molecules are used to create the ansible roles.
How to install Ansible Molecule:pip install molecule
How to verify the molecule version:$ molecule –version result : molecule, version 2.19.0
What is Ansible galaxy?
Ansible galaxy is site where the ansible developers collaborate to share ansible roles via installing roles, managing roles etc.
How to Initialize a role using Molecule ?Molecule could init a role. The init command can internally access Ansible galaxy. So molecule can generate a directory which has a directory with default as name. Inside that default directory, test build and run can be performed using docker container.Molecule.yml will have all test scenarios like how to lint and test the roles and playbook.yml is used to test the roles.
What is DNS?
Think about olden time, we used to keep phone book to find contact numbers. DNS is like a phone book of IP address.
How Does DNS resolution work Generally?DNS resolution is the process converting domain name (e.g. shalimatech.com ) to computer friendly Ip number. Since this IP number is mapped to computer the requests go to that device and that’s when a request is sent to shalimatech.com the IP gets the resources back to the user.
How Does DNS resolution work in Kubernetes clusters?
DNS resolution is done vis Kubernetes’s CoreDNS. Once you refer resolve.conf then you would understand how kubelets configures this.
PSScriptAnalyzer is code quality scanner developed by Microsoft to scan powershell code.
PSScriptAnalyzer can be installed using below command in Powershell ISE
“Install-Module -Name PSScriptAnalyzer”
PSScriptAnalyzer cmndlet to unit test powershell code below:
“Invoke-ScriptAnalyzer -Path ‘path of targetted ps1 file to be scanned for code quality’
When I wanted to run my automation scripts on CI/CD pipeline back in 2017, I was experimenting the headless browsers using HtmlUnitDriver
Now Chrome headless picked up popularity over HtmlUnitDriver as switching from GUI browser selenium code to Chrome headless is very easy unlike HtmlUnitDriver.
Selenium automation utilized HtmlUnitDriver when it needs a non GUI mode executions on jenkins server when there is no browser installed on it or no support from docker containers.
When I wanted to run my automation scripts on CI/CD pipeline back in 2017, I was experimenting the headless browsers starting with PhantomJs.
Now Phantomjs is a discontinuoed headless browsers due to poor maintenance and support.
Selenium automation utilized PhantomJs when it needs a non GUI mode executions on jenkins server when there is no browser installed on it or no support from docker containers.
Machine learning models can be developed using TensorFlow, and orchastrated using Kubernetes and build it in Docker container. These can be combined with AWS services like CloudWatch, EKS and S3. This can basically give an API for developers to deploy their machine learning models.
What is Tensorflow?
Tensorflow is an opensource library used for machine learning specifically artificial neural networks. It provides API for various machine learning tasks.
It is important to learn following terminology prior learning Tensorflow.
Artificial neural networks are inspired from Animal brains that learn from experiences. Similarly neural networks learns from examples to perform its tasks than running predefined programs.
What is Keras
High level neural networks API written in python which Tensorflow utilized for building its programs.
What is Dense
Dense is the neural network layer in the tensorflow