From 2371a28807b7ab54a4c102246caef2bf9087d45d Mon Sep 17 00:00:00 2001 From: Rohini-996 Date: Sat, 24 Jan 2026 11:05:15 +0000 Subject: [PATCH 01/13] Day 01: Added learning plan --- 2026/day-01/learning-plan.md | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 2026/day-01/learning-plan.md diff --git a/2026/day-01/learning-plan.md b/2026/day-01/learning-plan.md new file mode 100644 index 000000000..dbb54de9c --- /dev/null +++ b/2026/day-01/learning-plan.md @@ -0,0 +1,25 @@ +This is my Day-01 to kickstart my Devops journey + +I am starting a 90DaysOfDevOpsChallenge conducted by @Shubham Londhe #TrainWithShubham + +There are few tasks which i want to complete as day-01 tasks + + +1. What is your understanding of DevOps and Cloud Engineering? +Answer: I am BCS 3rd year student and Devops fresher. A term DevOps is combination of devlopment+operations. DevOps focuses on automation,monitoring by build, test and deploy code through CI/CD pipeline and make the code fully automated using terraform. DevOps is such a great field if you love doing automate things, if you don't want to use logic in your code , if you are able to solve errors by seeing logs of your code then absoluetly devops is must have skill. + + + +2. Why you are starting learning DevOps & Cloud? +Answer: I am learning DevOps and Cloud because I truly enjoy automating things and seeing my work run in real systems. Ilike fixing issues by checking logs, understanding how applications work in production, and making deployments faster and smoother. DevOps excites me because it is practical, hands-on, and lets me build and manage real-world infrastructure. +I want to build strong skills in Linux troubleshooting, CI/CD automation, and managing cloud infrastructure using tools like Docker and Terraform. + + + +3. Where do you want to reach? +Answer: In the next 90 days, I want to build strong hands-on DevOps skills by working on real projects and understandinghow production systems work. My goal is to confidently deploy and manage applications using Docker, CI/CD pipelines, andbasic Kubernetes on the cloud. I also want to be job-ready for entry-level DevOps or Cloud roles by the end of this learning journey. + + + +4. How you will stay consistent every single day? +Answer: I will follow a fixed daily study schedule and spend at least 4 hours on weekdays by focusing on hands-on and 5-6 hours on weekends by doing live lecture and practicing after lecture and will track my daily progress to stay consistent. Even on busy or low-energy days, I will ensure I do something small so that the learning period never breaks. From 365b89608380fb6a9ba9263c88bb53c9be794030 Mon Sep 17 00:00:00 2001 From: Rohini-996 Date: Mon, 26 Jan 2026 08:39:19 +0000 Subject: [PATCH 02/13] Completed Day-02 tasks --- 2026/day-02/linux-architecture-notes.md | 53 +++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 2026/day-02/linux-architecture-notes.md diff --git a/2026/day-02/linux-architecture-notes.md b/2026/day-02/linux-architecture-notes.md new file mode 100644 index 000000000..ba86d4f59 --- /dev/null +++ b/2026/day-02/linux-architecture-notes.md @@ -0,0 +1,53 @@ +This is my Day-02 of my #90DaysOfDevOpschallenge + +Today my task is to understand linux-architecture in depth + +. But first I will explain what linux actually is then i'll move to tasks +Answer: Linux is an operating system just like windows or macOs + Linux is very powerful OS if a website is running 24/7 that means its usually running on OS Linux + Linux focuses on control, speed, and stability. Instead of focusing on looks +Linux works on ask architecture now many people say what is ask? + +ASK is Application, Shell & Kernel + +1. Application (What you want to do) + Applications are the programs you use. +Examples: +ls, cp, ps, nginx, docker, mysql +. Applications cannot directly talk to hardware. + +2. Shell (How you ask) + The shell is the middleman. +Example: +bash, sh + What really happens: + . Shell reads your command + . Shell understands it + . Shell passes the request to the kernel +Think of shell as: +A translator between human language and system language + +3. Kernel (Who actually does the work) +The kernel is a boss πŸ‘‘ +. It Talks to CPU, memory, disk, network +. Creates and manages processes +. Decides which app gets CPU +. Handles system things +Without kernel a linux System is nothing + +A simple linux OS flow +You β†’ Application β†’ Shell β†’ Kernel β†’ Hardware + +Now let's move to our Day-02 tasks + +1. The core components of Linux (kernel, user space, init/systemd) +Answer: . The kernel is the core of Linux.it directly talks to hardware like CPU, memory, and disk.it manages processes and system resources. + . User space is where users and applications run. it includes commands, shells, and software like nginx or docker. user space requests services from the kernel + . Systemd is the core componet of Linux OS. systemd is the first process started when Linux restarts. It starts, stops, and manages system services. it keeps the system running and handles service failures. + +2. How processes are created and managed +Answer: When you run a command or start an application in Linux, the system creates a process for it. Each process is given a unique ID so the system can tr ack it,the Linux kernel manages all processes by deciding when they run, how much CPU and memory they use, and when they should wait or stop.Once a process finishes its work, the kernel cleans it up and frees the system resources, keeping Linux stable and efficient. + +3. What systemd does and why it matters +Answer: systemd is the first process that starts when Linux restarts and is responsible for starting, stopping, and managing system services. It ensures tha t important services run in the correct order and automatically restarts them if they fail. It matters because it keeps the system stable, helps + troubleshoot issues through logs, and ensures applications stay running in various environments. From 76b2a53a55947db89e964d60b96fbbba00806d48 Mon Sep 17 00:00:00 2001 From: Rohini-996 Date: Sat, 31 Jan 2026 13:59:38 +0530 Subject: [PATCH 03/13] Create linux-commands-cheatsheet.md --- 2026/day-03/linux-commands-cheatsheet.md | 158 +++++++++++++++++++++++ 1 file changed, 158 insertions(+) create mode 100644 2026/day-03/linux-commands-cheatsheet.md diff --git a/2026/day-03/linux-commands-cheatsheet.md b/2026/day-03/linux-commands-cheatsheet.md new file mode 100644 index 000000000..1a42388e0 --- /dev/null +++ b/2026/day-03/linux-commands-cheatsheet.md @@ -0,0 +1,158 @@ +Today is Day 03 of #90DaysOfDevOpsChallenge + +Today's task is about popular linux commands which we used in production enviornment + +1. Process Management Commands +. Command Usage +- ps = Show running processes +- ps aux = Show all running processes +- top = Real-time process monitoring +- htop = Enhanced process viewer +- pidof = process Get process ID +- kill PID = Kill process by PID +- kill -9 PID = Force kill process +- pkill name = Kill process by name +- uptime = Show system running time +- free -h = Show memory usage +- watch command = Run command repeatedly + +2. πŸ—‚οΈ File System Commands +. Command Usage +- ls = List files and directories +- ls -l = List files and permissions of file +- pwd = Show current directory path +- cd = Change directory +- mkdir Devops = Create a directory called Devops +- rm file = Delete a file +- rm -rf Devops = Force delete directory Devops +- cp src dest Copy file +- cp -r src dest Copy directory recursively +- mv src dest Move or rename file +- find /path -name file Find file by name +- du -sh * Show directory sizes +- df -h Show disk usage + +🌐 Networking & Troubleshooting Commands +Command Usage +ping google.com Check network connectivity +ip addr Show IP addresses +ip route Show routing table +ss -tuln Show listening ports +netstat -tulnp Show ports with PID +curl url Test API or URL response +wget url Download file +traceroute host Trace network path +dig domain DNS lookup +πŸ“„ File Viewing & Text Utilities +Command Usage +cat file View file content +less file Scroll file content +head file View first lines +tail file View last lines +tail -f file Live log monitoring +wc -l file Count lines +grep word file Search text +grep -r word dir Recursive search +πŸ” Permissions & Ownership +Command Usage +chmod 755 file Change permissions +chmod +x file Make executable + + + + +# Linux Commands Cheat Sheet (Day 03) + +This cheat sheet focuses on **real-world Linux troubleshooting**. Commands are grouped for quick scanning and daily reuse. + +--- + +## πŸ—‚οΈ File System Commands + +| Command | Usage | +| ----------------------- | --------------------------------------------- | +| `ls` | List files and directories | +| `ls -lh` | List files with size in human-readable format | +| `pwd` | Show current directory path | +| `cd /path` | Change directory | +| `mkdir dir` | Create a directory | +| `mkdir -p a/b/c` | Create nested directories | +| `rm file` | Delete a file | +| `rm -rf dir` | Force delete directory | +| `cp src dest` | Copy file | +| `cp -r src dest` | Copy directory recursively | +| `mv src dest` | Move or rename file | +| `find /path -name file` | Find file by name | +| `du -sh *` | Show directory sizes | +| `df -h` | Show disk usage | + +--- + +## βš™οΈ Process Management Commands + +| Command | Usage | +| --------------- | ---------------------------- | +| `ps` | Show running processes | +| `ps aux` | Show all running processes | +| `top` | Real-time process monitoring | +| `htop` | Enhanced process viewer | +| `pidof process` | Get process ID | +| `kill PID` | Kill process by PID | +| `kill -9 PID` | Force kill process | +| `pkill name` | Kill process by name | +| `uptime` | Show system running time | +| `free -h` | Show memory usage | +| `watch command` | Run command repeatedly | + +--- + +## 🌐 Networking & Troubleshooting Commands + +| Command | Usage | +| ----------------- | -------------------------- | +| `ping google.com` | Check network connectivity | +| `ip addr` | Show IP addresses | +| `ip route` | Show routing table | +| `ss -tuln` | Show listening ports | +| `netstat -tulnp` | Show ports with PID | +| `curl url` | Test API or URL response | +| `wget url` | Download file | +| `traceroute host` | Trace network path | +| `dig domain` | DNS lookup | + +--- + +## πŸ“„ File Viewing & Text Utilities + +| Command | Usage | +| ------------------ | ------------------- | +| `cat file` | View file content | +| `less file` | Scroll file content | +| `head file` | View first lines | +| `tail file` | View last lines | +| `tail -f file` | Live log monitoring | +| `wc -l file` | Count lines | +| `grep word file` | Search text | +| `grep -r word dir` | Recursive search | + +--- + +## πŸ” Permissions & Ownership + +| Command | Usage | +| ----------------------- | -------------------- | +| `chmod 755 file` | Change permissions | +| `chmod +x file` | Make executable | +| `chown user file` | Change owner | +| `chown user:group file` | Change owner & group | + +--- + +### βœ… Pro Tip + +Keep this cheat sheet open while troubleshooting production systems. Speed matters more than memorization. + +**Next Step:** Practice these commands on real logs, processes, and network checks. + +chown user file Change owner +chown user:group file Change owner & group From bef987e8318296b3898a1e8dab3970df99f09611 Mon Sep 17 00:00:00 2001 From: Rohini-996 Date: Sat, 31 Jan 2026 14:01:59 +0530 Subject: [PATCH 04/13] Update linux-commands-cheatsheet.md --- 2026/day-03/linux-commands-cheatsheet.md | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/2026/day-03/linux-commands-cheatsheet.md b/2026/day-03/linux-commands-cheatsheet.md index 1a42388e0..c060d5f87 100644 --- a/2026/day-03/linux-commands-cheatsheet.md +++ b/2026/day-03/linux-commands-cheatsheet.md @@ -4,17 +4,17 @@ Today's task is about popular linux commands which we used in production enviorn 1. Process Management Commands . Command Usage -- ps = Show running processes -- ps aux = Show all running processes -- top = Real-time process monitoring -- htop = Enhanced process viewer -- pidof = process Get process ID -- kill PID = Kill process by PID -- kill -9 PID = Force kill process -- pkill name = Kill process by name -- uptime = Show system running time -- free -h = Show memory usage -- watch command = Run command repeatedly +- ps = Show running processes +- ps aux = Show all running processes +- top = Real-time process monitoring +- htop = Enhanced process viewer +- pidof = process Get process ID +- kill PID = Kill process by PID +- kill -9 PID = Force kill process +- pkill name = Kill process by name +- uptime = Show system running time +- free -h = Show memory usage +- watch command = Run command repeatedly 2. πŸ—‚οΈ File System Commands . Command Usage From 541529315de9142512a547a34ef6c4e6a99678eb Mon Sep 17 00:00:00 2001 From: Rohini-996 Date: Sat, 31 Jan 2026 14:05:10 +0530 Subject: [PATCH 05/13] Update linux-commands-cheatsheet.md --- 2026/day-03/linux-commands-cheatsheet.md | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/2026/day-03/linux-commands-cheatsheet.md b/2026/day-03/linux-commands-cheatsheet.md index c060d5f87..a8b8d72ab 100644 --- a/2026/day-03/linux-commands-cheatsheet.md +++ b/2026/day-03/linux-commands-cheatsheet.md @@ -4,7 +4,7 @@ Today's task is about popular linux commands which we used in production enviorn 1. Process Management Commands . Command Usage -- ps = Show running processes +- ps = Show running processes - ps aux = Show all running processes - top = Real-time process monitoring - htop = Enhanced process viewer @@ -16,6 +16,19 @@ Today's task is about popular linux commands which we used in production enviorn - free -h = Show memory usage - watch command = Run command repeatedly +printf "ps\t\t= Show running processes\n" +printf "ps aux\t\t= Show all running processes\n" +printf "top\t\t= Real-time process monitoring\n" +printf "htop\t\t= Enhanced process viewer\n" +printf "pidof process\t= Get process ID\n" +printf "kill PID\t= Kill process by PID\n" +printf "kill -9 PID\t= Force kill process\n" +printf "pkill name\t= Kill process by name\n" +printf "uptime\t\t= Show system running time\n" +printf "free -h\t\t= Show memory usage\n" +printf "watch command\t= Run command repeatedly\n" + + 2. πŸ—‚οΈ File System Commands . Command Usage - ls = List files and directories From 9e1386fbf58a52e7391369abe8ef83432035cb90 Mon Sep 17 00:00:00 2001 From: Rohini-996 Date: Sat, 31 Jan 2026 14:20:32 +0530 Subject: [PATCH 06/13] Update linux-commands-cheatsheet.md --- 2026/day-03/linux-commands-cheatsheet.md | 163 ++++------------------- 1 file changed, 28 insertions(+), 135 deletions(-) diff --git a/2026/day-03/linux-commands-cheatsheet.md b/2026/day-03/linux-commands-cheatsheet.md index a8b8d72ab..957d889ee 100644 --- a/2026/day-03/linux-commands-cheatsheet.md +++ b/2026/day-03/linux-commands-cheatsheet.md @@ -16,18 +16,6 @@ Today's task is about popular linux commands which we used in production enviorn - free -h = Show memory usage - watch command = Run command repeatedly -printf "ps\t\t= Show running processes\n" -printf "ps aux\t\t= Show all running processes\n" -printf "top\t\t= Real-time process monitoring\n" -printf "htop\t\t= Enhanced process viewer\n" -printf "pidof process\t= Get process ID\n" -printf "kill PID\t= Kill process by PID\n" -printf "kill -9 PID\t= Force kill process\n" -printf "pkill name\t= Kill process by name\n" -printf "uptime\t\t= Show system running time\n" -printf "free -h\t\t= Show memory usage\n" -printf "watch command\t= Run command repeatedly\n" - 2. πŸ—‚οΈ File System Commands . Command Usage @@ -45,127 +33,32 @@ printf "watch command\t= Run command repeatedly\n" - du -sh * Show directory sizes - df -h Show disk usage -🌐 Networking & Troubleshooting Commands -Command Usage -ping google.com Check network connectivity -ip addr Show IP addresses -ip route Show routing table -ss -tuln Show listening ports -netstat -tulnp Show ports with PID -curl url Test API or URL response -wget url Download file -traceroute host Trace network path -dig domain DNS lookup -πŸ“„ File Viewing & Text Utilities -Command Usage -cat file View file content -less file Scroll file content -head file View first lines -tail file View last lines -tail -f file Live log monitoring -wc -l file Count lines -grep word file Search text -grep -r word dir Recursive search -πŸ” Permissions & Ownership -Command Usage -chmod 755 file Change permissions -chmod +x file Make executable - - - - -# Linux Commands Cheat Sheet (Day 03) - -This cheat sheet focuses on **real-world Linux troubleshooting**. Commands are grouped for quick scanning and daily reuse. - ---- - -## πŸ—‚οΈ File System Commands - -| Command | Usage | -| ----------------------- | --------------------------------------------- | -| `ls` | List files and directories | -| `ls -lh` | List files with size in human-readable format | -| `pwd` | Show current directory path | -| `cd /path` | Change directory | -| `mkdir dir` | Create a directory | -| `mkdir -p a/b/c` | Create nested directories | -| `rm file` | Delete a file | -| `rm -rf dir` | Force delete directory | -| `cp src dest` | Copy file | -| `cp -r src dest` | Copy directory recursively | -| `mv src dest` | Move or rename file | -| `find /path -name file` | Find file by name | -| `du -sh *` | Show directory sizes | -| `df -h` | Show disk usage | - ---- - -## βš™οΈ Process Management Commands - -| Command | Usage | -| --------------- | ---------------------------- | -| `ps` | Show running processes | -| `ps aux` | Show all running processes | -| `top` | Real-time process monitoring | -| `htop` | Enhanced process viewer | -| `pidof process` | Get process ID | -| `kill PID` | Kill process by PID | -| `kill -9 PID` | Force kill process | -| `pkill name` | Kill process by name | -| `uptime` | Show system running time | -| `free -h` | Show memory usage | -| `watch command` | Run command repeatedly | - ---- - -## 🌐 Networking & Troubleshooting Commands - -| Command | Usage | -| ----------------- | -------------------------- | -| `ping google.com` | Check network connectivity | -| `ip addr` | Show IP addresses | -| `ip route` | Show routing table | -| `ss -tuln` | Show listening ports | -| `netstat -tulnp` | Show ports with PID | -| `curl url` | Test API or URL response | -| `wget url` | Download file | -| `traceroute host` | Trace network path | -| `dig domain` | DNS lookup | - ---- - -## πŸ“„ File Viewing & Text Utilities - -| Command | Usage | -| ------------------ | ------------------- | -| `cat file` | View file content | -| `less file` | Scroll file content | -| `head file` | View first lines | -| `tail file` | View last lines | -| `tail -f file` | Live log monitoring | -| `wc -l file` | Count lines | -| `grep word file` | Search text | -| `grep -r word dir` | Recursive search | - ---- - -## πŸ” Permissions & Ownership - -| Command | Usage | -| ----------------------- | -------------------- | -| `chmod 755 file` | Change permissions | -| `chmod +x file` | Make executable | -| `chown user file` | Change owner | -| `chown user:group file` | Change owner & group | - ---- - -### βœ… Pro Tip - -Keep this cheat sheet open while troubleshooting production systems. Speed matters more than memorization. - -**Next Step:** Practice these commands on real logs, processes, and network checks. +3. 🌐 Networking & Troubleshooting Commands +. Command Usage +- ping google.com = Check network connectivity of google.com +- ip addr = Used to show IP addresses +- ip route = Show routing table +- ss -tuln = Show listening ports +- netstat -tulnp = Show ports with PID +- curl url = Test API or URL response +- wget url = Download file +- traceroute = Trace network path shows where failure happen + +4. πŸ“„ File Viewing & Text Utilities +. Command Usage +- cat (file) = View file content +- less (file) = Scroll file content +- head (file) -n 5 = View first 5 lines of file +- tail (file) = View last 5 lines of file +- tail -f (file) = Live log monitoring +- wc -l (file) = Count lines +- grep word (file) = Search text + +5. πŸ” Permissions & Ownership +. Command Usage +. chmod 755 file = Change permissions to +x rw and rw +. chmod +x file = Make file executable +. chgrp = Change group +. chown = Change owner -chown user file Change owner -chown user:group file Change owner & group +. This cheatsheet commands is very useful in troubleshooting accessing files giving permissions & for process managment From a45d2a90681fbc4c723c915c4f38196dd6544300 Mon Sep 17 00:00:00 2001 From: Rohini-996 Date: Sat, 31 Jan 2026 14:23:55 +0530 Subject: [PATCH 07/13] Update linux-commands-cheatsheet.md --- 2026/day-03/linux-commands-cheatsheet.md | 45 ++++++++++++------------ 1 file changed, 23 insertions(+), 22 deletions(-) diff --git a/2026/day-03/linux-commands-cheatsheet.md b/2026/day-03/linux-commands-cheatsheet.md index 957d889ee..23750c42e 100644 --- a/2026/day-03/linux-commands-cheatsheet.md +++ b/2026/day-03/linux-commands-cheatsheet.md @@ -2,23 +2,24 @@ Today is Day 03 of #90DaysOfDevOpsChallenge Today's task is about popular linux commands which we used in production enviornment -1. Process Management Commands -. Command Usage -- ps = Show running processes -- ps aux = Show all running processes -- top = Real-time process monitoring -- htop = Enhanced process viewer -- pidof = process Get process ID -- kill PID = Kill process by PID -- kill -9 PID = Force kill process -- pkill name = Kill process by name -- uptime = Show system running time -- free -h = Show memory usage -- watch command = Run command repeatedly +| Command | Usage | +|---------------|------| +| ps | Show running processes | +| ps aux | Show all running processes | +| top | Real-time process monitoring | +| htop | Enhanced process viewer | +| pidof process | Get process ID | +| kill PID | Kill process by PID | +| kill -9 PID | Force kill process | +| pkill name | Kill process by name | +| uptime | Show system running time | +| free -h | Show memory usage | +| watch command | Run command repeatedly | + 2. πŸ—‚οΈ File System Commands -. Command Usage +- Command Usage - ls = List files and directories - ls -l = List files and permissions of file - pwd = Show current directory path @@ -34,7 +35,7 @@ Today's task is about popular linux commands which we used in production enviorn - df -h Show disk usage 3. 🌐 Networking & Troubleshooting Commands -. Command Usage +- Command Usage - ping google.com = Check network connectivity of google.com - ip addr = Used to show IP addresses - ip route = Show routing table @@ -45,7 +46,7 @@ Today's task is about popular linux commands which we used in production enviorn - traceroute = Trace network path shows where failure happen 4. πŸ“„ File Viewing & Text Utilities -. Command Usage +- Command Usage - cat (file) = View file content - less (file) = Scroll file content - head (file) -n 5 = View first 5 lines of file @@ -55,10 +56,10 @@ Today's task is about popular linux commands which we used in production enviorn - grep word (file) = Search text 5. πŸ” Permissions & Ownership -. Command Usage -. chmod 755 file = Change permissions to +x rw and rw -. chmod +x file = Make file executable -. chgrp = Change group -. chown = Change owner +- Command Usage +- chmod 755 file = Change permissions to +x rw and rw +- chmod +x file = Make file executable +- chgrp = Change group +- chown = Change owner -. This cheatsheet commands is very useful in troubleshooting accessing files giving permissions & for process managment +- This cheatsheet commands is very useful in troubleshooting accessing files giving permissions & for process managment From c4a555417f719ebcab8d618c768e592e766ca99b Mon Sep 17 00:00:00 2001 From: Rohini-996 Date: Sat, 31 Jan 2026 14:25:50 +0530 Subject: [PATCH 08/13] Update linux-commands-cheatsheet.md --- 2026/day-03/linux-commands-cheatsheet.md | 27 ++++++++++++------------ 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/2026/day-03/linux-commands-cheatsheet.md b/2026/day-03/linux-commands-cheatsheet.md index 23750c42e..b305c7e9d 100644 --- a/2026/day-03/linux-commands-cheatsheet.md +++ b/2026/day-03/linux-commands-cheatsheet.md @@ -2,19 +2,20 @@ Today is Day 03 of #90DaysOfDevOpsChallenge Today's task is about popular linux commands which we used in production enviornment -| Command | Usage | -|---------------|------| -| ps | Show running processes | -| ps aux | Show all running processes | -| top | Real-time process monitoring | -| htop | Enhanced process viewer | -| pidof process | Get process ID | -| kill PID | Kill process by PID | -| kill -9 PID | Force kill process | -| pkill name | Kill process by name | -| uptime | Show system running time | -| free -h | Show memory usage | -| watch command | Run command repeatedly | +``` +ps = Show running processes +ps aux = Show all running processes +top = Real-time process monitoring +htop = Enhanced process viewer +pidof process = Get process ID +kill PID = Kill process by PID +kill -9 PID = Force kill process +pkill name = Kill process by name +uptime = Show system running time +free -h = Show memory usage +watch command = Run command repeatedly +``` + From bd126303ce8f300b638659bbda2a856eea3cd0ea Mon Sep 17 00:00:00 2001 From: Rohini-996 Date: Sat, 31 Jan 2026 14:28:36 +0530 Subject: [PATCH 09/13] Update linux-commands-cheatsheet.md --- 2026/day-03/linux-commands-cheatsheet.md | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/2026/day-03/linux-commands-cheatsheet.md b/2026/day-03/linux-commands-cheatsheet.md index b305c7e9d..24cf80862 100644 --- a/2026/day-03/linux-commands-cheatsheet.md +++ b/2026/day-03/linux-commands-cheatsheet.md @@ -1,6 +1,7 @@ -Today is Day 03 of #90DaysOfDevOpsChallenge +. Today is Day 03 of #90DaysOfDevOpsChallenge -Today's task is about popular linux commands which we used in production enviornment +. Today's task is about popular linux commands which we used in production enviornment +1. Process Management Commands ``` ps = Show running processes @@ -21,6 +22,7 @@ watch command = Run command repeatedly 2. πŸ—‚οΈ File System Commands - Command Usage +``` - ls = List files and directories - ls -l = List files and permissions of file - pwd = Show current directory path @@ -34,9 +36,11 @@ watch command = Run command repeatedly - find /path -name file Find file by name - du -sh * Show directory sizes - df -h Show disk usage +``` 3. 🌐 Networking & Troubleshooting Commands - Command Usage +``` - ping google.com = Check network connectivity of google.com - ip addr = Used to show IP addresses - ip route = Show routing table @@ -45,9 +49,10 @@ watch command = Run command repeatedly - curl url = Test API or URL response - wget url = Download file - traceroute = Trace network path shows where failure happen - +``` 4. πŸ“„ File Viewing & Text Utilities - Command Usage +``` - cat (file) = View file content - less (file) = Scroll file content - head (file) -n 5 = View first 5 lines of file @@ -55,12 +60,14 @@ watch command = Run command repeatedly - tail -f (file) = Live log monitoring - wc -l (file) = Count lines - grep word (file) = Search text +``` 5. πŸ” Permissions & Ownership - Command Usage +``` - chmod 755 file = Change permissions to +x rw and rw - chmod +x file = Make file executable - chgrp = Change group - chown = Change owner - +``` - This cheatsheet commands is very useful in troubleshooting accessing files giving permissions & for process managment From 65f710116b8505051baac55de7c1d819299e57b7 Mon Sep 17 00:00:00 2001 From: Rohini-996 Date: Sat, 31 Jan 2026 14:30:08 +0530 Subject: [PATCH 10/13] Update linux-commands-cheatsheet.md --- 2026/day-03/linux-commands-cheatsheet.md | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/2026/day-03/linux-commands-cheatsheet.md b/2026/day-03/linux-commands-cheatsheet.md index 24cf80862..dc566c137 100644 --- a/2026/day-03/linux-commands-cheatsheet.md +++ b/2026/day-03/linux-commands-cheatsheet.md @@ -1,8 +1,8 @@ -. Today is Day 03 of #90DaysOfDevOpsChallenge +Today is Day 03 of #90DaysOfDevOpsChallenge -. Today's task is about popular linux commands which we used in production enviornment +Today's task is about popular linux commands which we used in production enviornment 1. Process Management Commands - +- Command Usage ``` ps = Show running processes ps aux = Show all running processes From a0a914eace80db427f2b4a25e6544fe28c64a06b Mon Sep 17 00:00:00 2001 From: Rohini-996 Date: Sat, 31 Jan 2026 16:10:29 +0530 Subject: [PATCH 11/13] Create linux-practice.md --- 2026/day-04/linux-practice.md | 98 +++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 2026/day-04/linux-practice.md diff --git a/2026/day-04/linux-practice.md b/2026/day-04/linux-practice.md new file mode 100644 index 000000000..5118b78c5 --- /dev/null +++ b/2026/day-04/linux-practice.md @@ -0,0 +1,98 @@ +Today is Day-04 of #90DaysOfDevopsChallenge + +Today’s goal is to practice Linux fundamentals with real commands + +1. Check running processes with output +Answer: a. ps + ``` + PID TTY TIME CMD + 725 pts/0 00:00:00 bash + 7695 pts/0 00:00:00 ps + ``` + b. top + ``` + top - 10:20:34 up 13 min, 1 user, load average: 0.38, 0.83, 0.79 + Tasks: 139 total, 1 running, 138 sleeping, 0 stopped, 0 zombie + %Cpu(s): 2.2 us, 2.3 sy, 0.0 ni, 93.5 id, 0.2 wa, 0.0 hi, 1.8 si, 0.0 st + MiB Mem : 3600.8 total, 76.5 free, 2955.2 used, 764.1 buff/cache + MiB Swap: 1024.0 total, 561.0 free, 463.0 used. 645.5 avail Mem + + PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND + 3363 root 20 0 1519436 235012 37852 S 6.3 6.4 1:12.76 kube-apiserver + 2364 root 20 0 3057440 38044 11936 S 4.7 1.0 0:30.38 containerd + ``` +2. Inspect one systemd service +Answer: systemctl status nginx +``` +ubuntu@LAPTOP-6F2K1CME:~$ systemctl status nginx +● nginx.service - A high performance web server and a reverse proxy server + Loaded: loaded (/usr/lib/systemd/system/nginx.service; enabled; preset: enabled) + Active: active (running) since Sat 2026-01-31 09:33:59 UTC; 48min ago + Docs: man:nginx(8) + Process: 233 ExecStartPre=/usr/sbin/nginx -t -q -g daemon on; master_process on; (code=exited, status=0/SUCCESS) + Process: 247 ExecStart=/usr/sbin/nginx -g daemon on; master_process on; (code=exited, status=0/SUCCESS) + Main PID: 260 (nginx) + Tasks: 9 (limit: 4312) + Memory: 5.6M () + CGroup: /system.slice/nginx.service + β”œβ”€260 "nginx: master process /usr/sbin/nginx -g daemon on; master_process on;" + β”œβ”€262 "nginx: worker process" +``` + +3. Capture a small troubleshooting flow +Answer: journalctl -u nginx +``` +ubuntu@LAPTOP-6F2K1CME:~$ journalctl -u nginx +Jan 18 08:10:11 LAPTOP-6F2K1CME systemd[1]: Starting nginx.service - A high performance web server and a reverse proxy > +Jan 18 08:10:23 LAPTOP-6F2K1CME systemd[1]: Started nginx.service - A high performance web server and a reverse proxy s> +Jan 18 09:12:39 LAPTOP-6F2K1CME systemd[1]: Starting nginx.service - A high performance web server and a reverse proxy > +Jan 18 09:12:40 LAPTOP-6F2K1CME systemd[1]: Started nginx.service - A high performance web server and a reverse proxy s> +-- Boot e117584ff66441df97f173806dee4589 -- +``` +. Tasks +1. process checks +- Command = ps aux | grep nginx +- Observation: +- Master and worker nginx processes are running +- nginx is active + +2. Service checks +- Command = systemctl status nginx +- Observation: +- nginx service is active (running) +- Shows uptime and main PID + +3. Log checks +- Command = journalctl -u nginx | tail -n 5 +- Observation: +- Shows nginx startup logs +- Helpful to debug + +4. Mini troubleshooting steps +- Scenario: NGINX service is down or website not loading + +- Step 1: Check service status +- systemctl status nginx + + +- Step 2: Check nginx logs +- journalctl -u nginx | tail -n 5 +- tail -n 5 /var/log/nginx/error.log + + +- Step 3: Test nginx configuration +- nginx -t + + +- Step 4: Restart nginx service +- sudo systemctl restart nginx + + +- Step 5: Verify service is running +- systemctl status nginx + + +- Result: +- Configuration validated +- nginx service restarted successfully +- Website accessible again From 4d6b1d0d88a9e2201d72169271399a16f0c89693 Mon Sep 17 00:00:00 2001 From: Rohini-996 Date: Sat, 31 Jan 2026 16:11:54 +0530 Subject: [PATCH 12/13] Update linux-practice.md --- 2026/day-04/linux-practice.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/2026/day-04/linux-practice.md b/2026/day-04/linux-practice.md index 5118b78c5..f3b9e4187 100644 --- a/2026/day-04/linux-practice.md +++ b/2026/day-04/linux-practice.md @@ -71,11 +71,11 @@ Jan 18 09:12:40 LAPTOP-6F2K1CME systemd[1]: Started nginx.service - A high perfo 4. Mini troubleshooting steps - Scenario: NGINX service is down or website not loading -- Step 1: Check service status +Step 1. Check service status - systemctl status nginx -- Step 2: Check nginx logs +Step 2. Check nginx logs - journalctl -u nginx | tail -n 5 - tail -n 5 /var/log/nginx/error.log From b0c9c089c0b5267b12dd07aa363a3af8d966ec0b Mon Sep 17 00:00:00 2001 From: Rohini-996 Date: Sat, 31 Jan 2026 16:12:53 +0530 Subject: [PATCH 13/13] Update linux-practice.md --- 2026/day-04/linux-practice.md | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/2026/day-04/linux-practice.md b/2026/day-04/linux-practice.md index f3b9e4187..2da4cbfa8 100644 --- a/2026/day-04/linux-practice.md +++ b/2026/day-04/linux-practice.md @@ -80,18 +80,17 @@ Step 2. Check nginx logs - tail -n 5 /var/log/nginx/error.log -- Step 3: Test nginx configuration +Step 3. Test nginx configuration - nginx -t -- Step 4: Restart nginx service +Step 4. Restart nginx service - sudo systemctl restart nginx -- Step 5: Verify service is running +Step 5. Verify service is running - systemctl status nginx - - Result: - Configuration validated - nginx service restarted successfully