Mastering Linux for DevOps: Users, Permissions & Log Analysis Like a Pro! 🚀

1️⃣ User & Group Management: Who's in Charge? 🕵️‍♂️

Understanding Users & Groups

Linux is all about users and groups! The /etc/passwd file holds user details, while /etc/group manages group memberships.

Task: Create a DevOps User & Grant Powers

Let’s get our hands dirty! 🛠️

• Create a user devops_user and add them to a group devops_team.

  

  Creating devops_team Group-

  

  Adding devops_user to devops_team group -

  

  • Set a password and grant sudo access.

Grant sudo access for devops_user -

• Restrict SSH login for certain users in /etc/ssh/sshd_config.

  Restrict SSH Login ⚠️

  sudo vim /etc/ssh/sshd_config

  Add the following lines:

  DenyUsers restricted_user

  AllowUsers devops_user

---

2️⃣ File & Directory Permissions: Lock it Down! 🔒

Task: Set Up Secure Workspaces

Create a directory and file for your top-secret DevOps projects:

• Create /devops_workspace and a file project_notes.txt.

  

  • Set permissions:

    • Owner can edit, group can read, others have no access.

Set Permissions 🔑

• Owner can edit.

• Group can read.

• Others have no access.

  

  Here, Read=4, Write=2, Execute=1. For Owner, set read & write (4+2). For Group, set read (4). For Others, set no access (0).

---

3️⃣ Log File Analysis with AWK, Grep & Sed: DevOps Detective Mode 🕵️

Task: Extract Insights from Logs

Logs are like breadcrumbs leading to the truth! Let’s analyze Linux_2k.log from LogHub.

Grab the Log File :

• Extract insights using commands:

  • Use grep to find all occurrences of the word "error".

    

    found no log with word error.

  • Use sed to replace all IP addresses with [REDACTED] for security

    

    Output : all IP addresses chnaged with [RADACTE]

    

    Boom! Now you're officially a Log Analysis Ninja. 🥷

---

🎯 Conclusion

Linux skills are a must-have for any DevOps engineer. In this guide, we: ✅ Explored the Linux file system & essential commands 📂 ✅ Managed users & groups 👤 ✅ Secured files with proper permissions 🔒 ✅ Analyzed logs using AWK, grep, and sed 📊

Keep practicing, and soon you'll be automating these like a pro! 🚀

Got any cool Linux hacks? Drop them in the comments! 👇