In Ruby, instance variables are variables that belong to a specific instance of a class. They are prefixed with the @ symbol and are accessible within the instance methods of that class. Instance variables allow objects to maintain state and store information unique to each instance. Example:

class Person
  def initialize(name, age)
    @name = name
    @age = age
  end

  def say_intro
    puts "Hello, my name is #{@name} and I am #{@age} years old"
  end
end

# Create a new instance of Person
person1 = Person.new("John", 18)

# Call the say_intro method
person1.say_intro

In this example, @name is an instance variable of the Person class, representing the name of each Person object created. The initialize method is a constructor that sets the value of @name when a new Person object is created. The say_intro method uses the instance variable @name to give the intro of the person with their name and age when called.

#ruby

The docker stats command is a powerful tool provided by Docker to monitor the resource usage of running containers. It provides a real-time stream of various metrics such as CPU usage, memory usage, network I/O, block I/O, and the number of processes (PIDs) running inside each container. This command is particularly useful for performance analysis and ensuring that containers are running within their resource limits. Example Explanation

docker stats db370fc6b784
CONTAINER ID   NAME       CPU %     MEM USAGE / LIMIT     MEM %     NET I/O          BLOCK I/O       PIDS
db370fc6b784   minikube   43.70%    1.243GiB / 2.148GiB   57.87%    35.4MB / 414MB

#devops #docker

We can check the default value for a given column using postgres query like this:

SELECT column_name, column_default
FROM information_schema.columns
WHERE table_name = '<table_name_placeholder>' AND column_name = '<column_name_placeholder>';

Same can be used for constraints like is_nullable as following:

SELECT column_name, is_nullable
FROM information_schema.columns
WHERE table_name = '<table_name_placeholder>' AND column_name = '<column_name_placeholder>';

#database #postgres #query

while integrating sentry with gitlab ip whitelisting needs to be done on gitlab server (self-hosted) #devops #sentry#gitlab

The kubectl cordon NODE_NAME command is used in Kubernetes to mark a node as unschedulable, meaning no new pods will be scheduled onto that node. Existing pods on the node will continue to run unless explicitly terminated or moved. #devops #kubernetes

Debugging Kubernetes pod on helm helm upgrade unleash-app-toggle . --debug Adding --debug can provide more insight if the error persists, showing exactly what values are being passed to each template. #devops #kubernetes #helm

Avoid Using Double Quotes for Environment Variables When configuring the PostgreSQL user and database names in a Helm values.yaml file, I initially wrapped the values in double quotes. This led to a frustrating issue where I couldn’t connect to the database, receiving errors that the role did not exist. The double quotes were being interpreted literally, causing mismatches in authentication. Solution: I removed the double quotes around the environment variables in my Helm chart and reapplied the configuration. This corrected the problem, and I was then able to connect successfully to the database. #devops #postgres #env

create the redis cluster from existing backup we can use snapshot_name = <name of your backyp > #devops #redis #Terraform

To find the number of pods that exist in the “dev” environment (env), you can use the kubectl get pods --selector=env=dev #devops #kubernetes