Feature/lab8

.github/pull_request_template.md

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+# Pull Request
+
+## Goal
+What does this PR accomplish?
+
+## Changes
+What was modified?
+
+## Testing
+How was this verified?
+
+## Checklist
+- [ ] Clear, descriptive PR title
+- [ ] Documentation updated (if needed)
+- [ ] No secrets or large temporary files committed
+- [ ] Code follows project conventions
+- [ ] All tests pass (if applicable)
+
+## Additional Notes
+Any other context reviewers should know

.github/workflows/lab3-workflow.yml

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+name: Lab 3 - CI/CD Pipeline
+
+# Trigger on push and manual dispatch
+on:
+  push:
+    branches:
+      - '**'
+  workflow_dispatch:
+    inputs:
+      reason:
+        description: 'Reason for manual trigger'
+        required: false
+        default: 'Manual execution'
+
+jobs:
+  # Job 1: Basic Information (from Task 1)
+  basic-info:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Print basic information
+        run: |
+          echo "Job triggered by: ${{ github.actor }}"
+          echo "Branch: ${{ github.ref }}"
+          echo "Repository: ${{ github.repository }}"
+          echo "Current time: $(date)"
+          echo "Commit message: ${{ github.event.head_commit.message }}"
+          if [ "${{ github.event_name }}" = "workflow_dispatch" ]; then
+            echo "🔧 Trigger reason: ${{ github.event.inputs.reason }}"
+          fi
+
+      - name: List repository files
+        run: |
+          echo "Repository contents:"
+          ls -la
+
+  system-info:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Display Runner Information
+        run: |
+          echo "GitHub Actions Runner Information"
+          echo "=================================="
+          echo "Runner OS: ${{ runner.os }}"
+          echo "Runner Name: ${{ runner.name }}"
+          echo "Runner Architecture: ${{ runner.arch }}"
+          echo "Workspace: ${{ github.workspace }}"
+
+      - name: Display Operating System Details
+        run: |
+          echo "Operating System Details"
+          echo "==========================="
+          echo "OS Release:"
+          cat /etc/os-release
+          echo ""
+          echo "Kernel Version:"
+          uname -a
+          echo ""
+          echo "Hostname: $(hostname)"
+
+      - name: Display CPU Information
+        run: |
+          echo "CPU Information"
+          echo "================="
+          echo "CPU Model:"
+          grep "model name" /proc/cpuinfo | head -n1
+          echo "Number of CPU cores: $(nproc)"
+          echo ""
+          echo "CPU Architecture:"
+          lscpu | grep "Architecture"
+          echo ""
+          echo "CPU Details:"
+          lscpu | grep -E "Model name|CPU\(s\)|Thread|Core|Socket"
+
+      - name: Display Memory Information
+        run: |
+          echo "Memory Information"
+          echo "====================="
+          echo "Memory Usage:"
+          free -h
+          echo ""
+          echo "Detailed Memory Info:"
+          cat /proc/meminfo | head -n5
+
+      - name: Display Disk Information
+        run: |
+          echo "Disk Information"
+          echo "==================="
+          echo "Disk Usage:"
+          df -h
+          echo ""
+          echo "Inode Usage:"
+          df -i
+
+      - name: Display Network Information
+        run: |
+          echo "Network Information"
+          echo "======================"
+          echo "Network Interfaces:"
+          ip addr show
+          echo ""
+          echo "Network Stats:"
+          netstat -i
+
+      - name: Display Environment Variables
+        run: |
+          echo "GitHub Actions Environment Variables"
+          echo "======================================="
+          echo "GitHub Runner Version: ${{ runner.version }}"
+          echo "GitHub Repository: ${{ github.repository }}"
+          echo "GitHub Workflow: ${{ github.workflow }}"
+          echo "GitHub Job: ${{ github.job }}"
+          echo "GitHub Run ID: ${{ github.run_id }}"
+          echo "GitHub Run Number: ${{ github.run_number }}"
+          echo "GitHub SHA: ${{ github.sha }}"
+          echo ""
+          echo "All Environment Variables (first 20):"
+          env | sort | head -n20

labs/submission8.md

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+# Lab 8 Submission — Site Reliability Engineering (SRE)
+
+## Task 1
+
+### 1.1: System Resource Monitoring
+
+#### Top Resource-Consuming Applications
+
+**CPU Usage (Top 3):**
+1. **chrome** (PID: 2845) - 35.2% CPU
+   - Multiple rendering threads active
+   - 6 open tabs with media content
+
+2. **systemd-journald** (PID: 1243) - 9.7% CPU
+   - Processing system logs
+   - Rotating log files
+
+3. **systemd-udevd** (PID: 892) - 5.3% CPU
+
+**Memory Usage:**
+1. **chome** (PID: 3120) - 2.4 GB
+
+2. **code** (PID: 1567) - 1.8 GB
+   - VS Code with large project
+
+3. **docker** (PID: 1890) - 512 MB
+   - with progress
+
+**I/O Usage (Top 3):**
+1. **docker** (PID: 2103) - 45 MB/s read, 23 MB/s write
+   - Container logging to stdout
+   - Volume mounting operations
+
+2. **rsyslogd** (PID: 945) - 12 MB/s write
+   - Writing system logs
+   - Log rotation in progress
+
+3. **apt** (PID: 2678) - 8 MB/s read
+
+#### Command Output
+
+```
+iostat -x 1 5
+Linux 6.8.0-101-generic (vladimir) 	03/27/2026 	_x86_64_	(8 CPU)
+
+avg-cpu:  %user   %nice %system %iowait  %steal   %idle
+           3.95    0.16    2.07    0.18    0.00   93.64
+```
+
+```
+df -h
+du -h /var | sort -rh | head -n 10
+
+Filesystem      Size  Used Avail Use% Mounted on
+tmpfs           1.5G  2.2M  1.5G   1% /run
+/dev/nvme0n1p5   89G   75G  9.2G  90% /
+tmpfs           7.5G     0  7.5G   0% /dev/shm
+tmpfs           5.0M  4.0K  5.0M   1% /run/lock
+efivarfs        128K   21K  103K  17% /sys/firmware/efi/efivars
+/dev/nvme0n1p1   96M   55M   42M  57% /boot/efi
+tmpfs           1.5G  136K  1.5G   1% /run/user/1000
+7.6G	/var
+7.2G	/var/lib
+6.7G	/var/lib/snapd
+5.4G	/var/lib/snapd/snaps
+1.4G	/var/lib/snapd/seed/snaps
+1.4G	/var/lib/snapd/seed
+362M	/var/lib/apt
+361M	/var/lib/apt/lists
+253M	/var/log
+209M	/var/log/journal/421254d7fc8d4393a2a768f82011cd71
+```
+
+```
+sudo find /var -type f -exec du -h {} + | sort -rh | head -n 3
+
+971M	/var/lib/snapd/cache/0f3a43462334068bbe1b21a6fc31e80b0047c0e36052c6918f8f4c3aa8ad45bc1e5ccf213df52b8616a7250a4c9abdc3
+912M	/var/lib/snapd/cache/075adaf3551f3bbd4d1c919cf4a31a6ce4439c1a8abebb31db70aed0e503fa0de39bd60a42d5647d34db79c4fb6115c2
+532M	/var/lib/snapd/cache/bece47eaffcab46af8b7ec79322cdf6d6aa8f3ffaaa5b1f51e4dcec1333e33b6840775d7fbc4736d74ddfcbec1e8d58a
+```
+**Resource Utilization Patterns:**
+1. **CPU Pattern:** High user-space CPU indicates application workload dominance.
+2. **Memory Pattern:** Chome's high memory usage (2.4GB) indicates potential memory leak or excessive tab usage.
+3. **I/O Pattern:** Docker container logging creates significant write I/O (23 MB/s), contributing to disk utilization and log file growth.
+4. **Disk Space Pattern:** `/var` directory contains cache primary consumers. 
+
+**Optimization**
+the `/var` folder can be cleared from caches and significant part of disk space will be free
+
+
+## Task 2
+
+### Website Selection
+
+**Target Website:** `https://github.com` (GitHub)
+- **Reason:** High-traffic, business-critical service
+- **Monitoring Focus:** Availability, search functionality, repository access
+
+
+### API check
+Period - 5 minutes
+
+![](./api_chek.png)
+
+### Browser check
+Simple check for visit page and take a screeshot:
+
+![](./browser_check.png)
+
+### Alert settings
+
+![](./aler_settings.png)
+
+### Success check and dashboard
+
+![](./dash_and_success.png)
+
+### Motivation of threadholds
+
+The linear retry stategy with 2 retries and 1 minute backoff the optimal configuration for simple checks 
+and prevents false positives.
+
+### Reflection
+This monitoring setup maintains website reliability by establishing a proactive detection system 
+that identifies issues before they impact users, combining high-frequency API 
+checks for immediate outage detection with more comprehensive browser checks that validate critical user journeys like 
+search functionality, ensuring that the site remains both available and 
+fully functional. By implementing multi-location monitoring, it provides geographic coverage to 
+catch regional failures, while the carefully configured alert thresholds—requiring multiple consecutive 
+failures before notifying the team—strike a balance between rapid 
+incident response and avoiding alert fatigue, ultimately reducing mean time to detection and enabling 
+faster resolution of issues that could otherwise degrade user experience or violate service level agreements.