Week 2 Done! 🚀 My DevOps Learning Journey 🎯

This week, I deep-dived into Shell Scripting for DevOps, exploring how to automate repetitive tasks, manage cloud resources, and interact with APIs using Linux commands. Learning these fundamentals has given me a better understanding of how scripting enhances efficiency in DevOps workflows. 💻⚡

🔍 Key Takeaways (Commands & Their Purpose)

✅ File Management & Navigation:

touch → Create a file.
vim → Open and edit files (Esc + i to insert, :wq! to save).
cd folder_name → Navigate to a directory.
cat → Read a file without opening it.
ls → List files in a directory.
chmod → Modify file permissions.
man → Get detailed command documentation.
sh or ./ → Execute a shell script.
pwd → Display the current directory.
mkdir → Create a new directory.
ls -ltr → List files with timestamps.
cd .. → Move back to the previous directory.
mv old new → Rename a file or script.

✅ System Monitoring & Process Management:

df → Check available storage.
free → View memory usage.
nproc → Find out the number of CPU cores.
top → Monitor running processes.
echo "text" → Print a message to the terminal.
set -x → Enable debug mode to see commands with output.
ps -ef → List all running processes.
ps -ef | grep "amazon" → Filter a specific process.
awk -F" " '{print $2}' → Extract column data from text.

✅ Piping & Filtering:

command | grep "info" → Filter output based on a keyword.
set -e → Exit the script if an error occurs.
set -o pipefail → Ensure the last command in a pipeline runs successfully.

✅ Networking & APIs:

curl → Fetch data from external sources.
curl <link> | grep error → Fetch logs and filter errors.
wget → Download files and analyze them.

✅ User Management & File Search:

find / -name pam.sd → Locate a file.
sudo su - → Switch to root user.
su username → Switch to a different user.

✅ Shell Scripting Fundamentals:

if-else → Conditional execution.
for → Loops for iteration.
trap "echo don't use the ctrl+c" SIGINT → Prevent script termination on Ctrl+C.

✅ AWS + Shell Scripting:

aws s3 ls → List objects in an S3 bucket.

⚡ Challenges & Fixes

🔹 Issue 1: Permission Errors in Shell Scripts
Problem: Running ./script.sh resulted in a "Permission Denied" error.
Solution: Used chmod +x script.sh to make it executable.

🔹 Issue 2: AWS CLI Output Parsing
Problem: AWS CLI JSON output was difficult to read.
Solution: Used jq for better formatting:

shCopyEditaws ec2 describe-instances | jq '.'

🚀 Next Steps: Diving deeper into advanced scripting, Git, and GitHub automation!

💡 Have you encountered similar issues in shell scripting? Let’s discuss in the comments! 👇

#DevOps #ShellScripting #AWS #GitHub #Automation #Linux #DevOpsJourney