Networking on Nerdsid.com

Docker Compose Basic

Wed, 01 Jul 2026 11:38:29 +0000

Introduction

In this lab, you’ll first deploy an application by setting up network, multiple containers individually. Then you will clean up resources, and deploy the same application using Docker Compose.

Task 1: Create a Bridge Network

Create a bridge network named clicknet.

 
 BASH
 
docker network create --driver bridge clicknet

Verify

list docker networks

$ docker network ls
NETWORK ID NAME DRIVER SCOPE
5aa54ade2dcc bridge bridge local
fc40bfcbce91 clicknet bridge local
238b23f4e2a9 host host local
59b9cbf97489 none null local

Task 2: Run a Redis Container

Create a background container named redis using the redis:alpine image and attach it to the clicknet network.

Docker Environment Variables and Networking

Tue, 16 Jun 2026 06:50:38 +0000

In this lab, we’ll explore:

Inspecting environment variables in running containers
Passing environment variables at runtime
Deploying MySQL containers
Creating custom Docker networks
Connecting applications and databases across containers

Task 1: Inspect Environment Variables

First, identify the value configured for the APP_COLOR environment variable in a running container.

List the running containers:

$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
cdf886f902d4 kodekloud/simple-webapp "python app.py" 10 minutes ago Up 10 minutes 8080/tcp mystifying_knuth

Inspect the container and look for the Env section:

Publishing Ports in Docker

Fri, 01 May 2026 14:37:01 +0000

Task

Solution

Show solution

This is the first paragraph of detailed content. This is the second paragraph of even more detailed content.

You can also include lists
Or other markdown elements

 
 service/networking/network-policy-default-deny-egress.yaml
 
 

 
 
---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
 name: default-deny-ingress
spec:
 podSelector: {}
 policyTypes:
 - Ingress

 
 BASH
 
ls -R /etc/
grep "name" file.txt

 
 PYTHON
 
name = "God"
greeting = f"Hello {name}"
print(greeting)

Terminal output

Before

Kill Any Process Using a Port in Powershell

Wed, 08 Apr 2026 05:17:46 +0000

Recently I wanted to start a server in port 8899 & I got an error telling that some other process is using it.

Here is a one-liner you can use to kill an existing process bound to a port.

 
 POWERSHELL
 
Stop-Process -Id (Get-NetTCPConnection -LocalPort 8899).OwningProcess -Force