TILs - Fueling Curiosity, One Insight at a Time

At Codemancers, we believe every day is an opportunity to grow. This section is where our team shares bite-sized discoveries, technical breakthroughs and fascinating nuggets of wisdom we've stumbled upon in our work.

Published
Author
user-image
Nisanth
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

Code

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
Published
Author
user-image
Vaibhav Yadav
Senior System Analyst
We can check the default value for a given column using postgres query like this:

Code

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:

Code

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


#database #postgres #query
Published
Author
user-image
Sujay
active_record_doctor performs variety of health checks to identify and rectify common database issues like missing foreign key constraints, missing NON NULL constraints, missing presence validations, incorrect presence validations on boolean columns and many more. Ref: https://github.com/gregnavis/active_record_doctor
#rails #database
Published
Author
user-image
Sagar Ghorse
while integrating sentry with gitlab ip whitelisting needs to be done on gitlab server (self-hosted)
#devops #sentry#gitlab
Published
Author
user-image
Soniya Rayabagi
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
Published
Author
user-image
Nisanth
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
Published
Author
user-image
Nisanth
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
Published
Author
user-image
Sagar Ghorse
create the redis cluster from existing backup we can use snapshot_name = <name of your backyp >
#devops #redis #Terraform
Published
Author
user-image
Nisanth
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
Published
Author
user-image
Sachin Kabadi
System Analyst
#nextJs #TypeScript
useEffect is a hook that allows you to perform side effects in function components.

Code

import React, { useState, useEffect } from 'react';

function MyComponent() {
  const [count, setCount] = useState(0);

  // This effect will run only when the count state changes
  useEffect(() => {
    document.title = `You clicked ${count} times`;
  }, [count]); // Only re-runs when count changes

  return (
    <div>
      <p>You clicked {count} times</p>
      <button onClick={() => setCount(count + 1)}>
        Click me
      </button>
    </div>
  );
}

export default MyComponent;


In the above example:
• We have a component MyComponent with a state variable count and a button to increment it.
• Inside the component, we use the useEffect hook to update the document title with the current count after each render.
• We pass [count] as the second argument to useEffect, which means the effect will only run when the count state changes. This is because we want to update the document title only when the count changes, not on every render.

Showing 25 to 27 of 82 results

Ready to Build Something Amazing?

Codemancers can bring your vision to life and help you achieve your goals

Let's Talk