inno-devops-labs · thallars · Feb 4, 2026 · Feb 4, 2026 · Mar 25, 2026
diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
@@ -0,0 +1,21 @@
+# Pull Request
+
+## Goal
+<!-- Clearly describe what this PR accomplishes -->
+
+## Changes
+<!-- List the main modifications in this PR -->
+- 
+- 
+- 
+
+## Testing
+<!-- Describe how you verified these changes work correctly -->
+- 
+- 
+- 
+
+## Checklist
+- [ ] Clear, descriptive PR title
+- [ ] Documentation/README updated (if needed)
+- [ ] No secrets or large temporary files committed
diff --git a/gitops-lab/current-state.txt b/gitops-lab/current-state.txt
@@ -0,0 +1,3 @@
+version: 1.0
+app: myapp
+replicas: 3
diff --git a/gitops-lab/desired-state.txt b/gitops-lab/desired-state.txt
@@ -0,0 +1,3 @@
+version: 1.0
+app: myapp
+replicas: 3
diff --git a/gitops-lab/health.log b/gitops-lab/health.log
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+Wed 25 Mar 2026 11:55:20 AM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 11:55:40 AM MSK - ❌ CRITICAL: State mismatch detected!
+  Desired MD5: a15a1a4f965ecd8f9e23a33a6b543155
+  Current MD5: 48168ff3ab5ffc0214e81c7e2ee356f5
+Wed 25 Mar 2026 11:59:36 AM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:06 PM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:09 PM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:12 PM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:15 PM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:18 PM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:21 PM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:24 PM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:27 PM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:30 PM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:33 PM MSK - ✅ OK: States synchronized
diff --git a/gitops-lab/healthcheck.sh b/gitops-lab/healthcheck.sh
@@ -0,0 +1,13 @@
+#!/bin/bash
+# healthcheck.sh - Monitor GitOps sync health
+
+DESIRED_MD5=$(md5sum desired-state.txt | awk '{print $1}')
+CURRENT_MD5=$(md5sum current-state.txt | awk '{print $1}')
+
+if [ "$DESIRED_MD5" != "$CURRENT_MD5" ]; then
+    echo "$(date) - ❌ CRITICAL: State mismatch detected!" | tee -a health.log
+    echo "  Desired MD5: $DESIRED_MD5" | tee -a health.log
+    echo "  Current MD5: $CURRENT_MD5" | tee -a health.log
+else
+    echo "$(date) - ✅ OK: States synchronized" | tee -a health.log
+fi
diff --git a/gitops-lab/monitor.sh b/gitops-lab/monitor.sh
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+#!/bin/bash
+# monitor.sh - Combined reconciliation and health monitoring
+
+echo "Starting GitOps monitoring..."
+for i in {1..10}; do
+    echo "\n--- Check #$i ---"
+    ./healthcheck.sh
+    ./reconcile.sh
+    sleep 3
+done
diff --git a/gitops-lab/reconcile.sh b/gitops-lab/reconcile.sh
@@ -0,0 +1,14 @@
+#!/bin/bash
+# reconcile.sh - GitOps reconciliation loop
+
+DESIRED=$(cat desired-state.txt)
+CURRENT=$(cat current-state.txt)
+
+if [ "$DESIRED" != "$CURRENT" ]; then
+    echo "$(date) - ⚠️  DRIFT DETECTED!"
+    echo "Reconciling current state with desired state..."
+    cp desired-state.txt current-state.txt
+    echo "$(date) - ✅ Reconciliation complete"
+else
+    echo "$(date) - ✅ States synchronized"
+fi
diff --git a/labs/submission7.md b/labs/submission7.md
@@ -0,0 +1,128 @@
+# Lab 7 — GitOps Fundamentals
+
+## Task 1 — Git State Reconciliation
+
+### Setup Desired State Configuration
+
+Initial desired-state.txt and current-state.txt contents:
+
+```
+version: 1.0
+app: myapp
+replicas: 3
+```
+
+```
+version: 1.0
+app: myapp
+replicas: 3
+```
+
+### Drift Detection and Reconciliation
+
+```bash
+thallars@ASUS-TUF:~/Documents/DevOps-Intro$ ./reconcile.sh
+Wed 25 Mar 2026 11:40:08 AM MSK - ⚠️  DRIFT DETECTED!
+Reconciling current state with desired state...
+Wed 25 Mar 2026 11:40:08 AM MSK - ✅ Reconciliation complete
+```
+
+Synchronized state after reconciliation:
+
+```bash
+thallars@ASUS-TUF:~/Documents/DevOps-Intro$ diff desired-state.txt current-state.txt
+thallars@ASUS-TUF:~/Documents/DevOps-Intro$ cat current-state.txt
+version: 1.0
+app: myapp
+replicas: 3
+```
+
+### Automated Continuous Reconciliation
+
+```bash
+Every 5.0s: ./reconcile.sh           ASUS-TUF: Wed Mar 25 11:43:02 2026
+
+Wed 25 Mar 2026 11:43:02 AM MSK - ⚠️  DRIFT DETECTED!
+Reconciling current state with desired state...
+Wed 25 Mar 2026 11:43:02 AM MSK - ✅ Reconciliation complete
+```
+
+### Analysis: Explain the GitOps reconciliation loop. How does this prevent configuration drift?
+
+The GitOps reconciliation loop continuously compares the live system state against the desired state defined in Git; if drift is detected, an automated agent immediately applies the Git-specified configuration to revert any manual changes or inconsistencies.
+
+### Reflection: What advantages does declarative configuration have over imperative commands in production?
+
+Declarative configuration provides a single source of truth, enabling version control, automated rollbacks, and consistency across environments, whereas imperative commands are error-prone, unrepeatable, and obscure the desired end state.
+
+## Task 2 — GitOps Health Monitoring
+
+### Health Check Script
+
+```bash
+#!/bin/bash
+# healthcheck.sh - Monitor GitOps sync health
+
+DESIRED_MD5=$(md5sum desired-state.txt | awk '{print $1}')
+CURRENT_MD5=$(md5sum current-state.txt | awk '{print $1}')
+
+if [ "$DESIRED_MD5" != "$CURRENT_MD5" ]; then
+    echo "$(date) - ❌ CRITICAL: State mismatch detected!" | tee -a health.log
+    echo "  Desired MD5: $DESIRED_MD5" | tee -a health.log
+    echo "  Current MD5: $CURRENT_MD5" | tee -a health.log
+else
+    echo "$(date) - ✅ OK: States synchronized" | tee -a health.log
+fi
+```
+
+### Test Health Monitoring
+
+Output showing "OK" status when states match:
+
+```bash
+thallars@ASUS-TUF:~/Documents/DevOps-Intro/gitops-lab$ ./healthcheck.sh
+Wed 25 Mar 2026 11:55:20 AM MSK - ✅ OK: States synchronized
+```
+
+Output showing "CRITICAL" status when drift is detected:
+
+```bash
+thallars@ASUS-TUF:~/Documents/DevOps-Intro/gitops-lab$ ./healthcheck.sh
+Wed 25 Mar 2026 11:55:40 AM MSK - ❌ CRITICAL: State mismatch detected!
+  Desired MD5: a15a1a4f965ecd8f9e23a33a6b543155
+  Current MD5: 48168ff3ab5ffc0214e81c7e2ee356f5
+```
+
+Complete health.log file showing multiple checks:
+
+```bash
+thallars@ASUS-TUF:~/Documents/DevOps-Intro/gitops-lab$ cat health.log
+Wed 25 Mar 2026 11:55:20 AM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 11:55:40 AM MSK - ❌ CRITICAL: State mismatch detected!
+  Desired MD5: a15a1a4f965ecd8f9e23a33a6b543155
+  Current MD5: 48168ff3ab5ffc0214e81c7e2ee356f5
+Wed 25 Mar 2026 11:59:36 AM MSK - ✅ OK: States synchronized
+```
+
+### Continuous Health Monitoring
+
+```bash
+thallars@ASUS-TUF:~/Documents/DevOps-Intro/gitops-lab$ cat health.log
+Wed 25 Mar 2026 11:55:20 AM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 11:55:40 AM MSK - ❌ CRITICAL: State mismatch detected!
+  Desired MD5: a15a1a4f965ecd8f9e23a33a6b543155
+  Current MD5: 48168ff3ab5ffc0214e81c7e2ee356f5
+Wed 25 Mar 2026 11:59:36 AM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:06 PM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:09 PM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:12 PM MSK - ✅ OK: States synchronized
+Wed 25 Mar 2026 12:02:15 PM MSK - ✅ OK: States synchronized
+```
+
+### Analysis: How do checksums (MD5) help detect configuration changes?
+
+Checksums (MD5) generate a unique fingerprint of a configuration file's content; any unauthorized or accidental change alters the fingerprint, allowing the system to immediately detect and flag the drift.
+
+### Comparison: How does this relate to GitOps tools like ArgoCD's "Sync Status"?
+
+ArgoCD's "Sync Status" uses similar hashing logic—it compares the live resource's hash against the desired state's hash from Git—to determine if the cluster is "Synced" (matching) or "OutOfSync" (drifted), automating the detection process that a manual MD5 check would serve.