Mysteri0K1ng · Mysteri0K1ng · Jun 8, 2026 · Jun 8, 2026 · Jun 9, 2026 · Jun 9, 2026
diff --git a/submissions/lab2.md b/submissions/lab2.md
@@ -0,0 +1,373 @@
+important work
+more important work
+
+# Task 1
+
+## 1.1  Explore your repo's plumbing
+
+Command:
+
+```bash
+git rev-parse HEAD
+```
+
+Output:
+
+```bash
+f3c449b71f05345adc17eb0f2edc9a43ff076d15
+
+```
+
+Command:
+
+```bash
+git cat-file -t HEAD
+```
+
+Output:
+
+```bash
+commit
+
+```
+
+Command:
+
+```bash
+git cat-file -p HEAD
+
+```
+
+Output:
+
+```bash
+tree b2fe0c7c5e1b86c2995fdccb8e8b18e8a19fd322
+parent 027e77b74d10d71bd481aa3815bc4c8ab6574212
+author Nikita Schankin <nikita.sshankin@gmail.com> 1780947044 +0300
+committer Nikita Schankin <nikita.sshankin@gmail.com> 1780947044 +0300
+
+test: unsigned commit (should fail)
+
+Signed-off-by: Nikita Schankin <nikita.sshankin@gmail.com>
+
+
+```
+
+Command:
+
+```bash
+git cat-file -p b2fe0c7c5e1b86c2995fdccb8e8b18e8a19fd322
+```
+
+Output:
+
+```bash
+040000 tree 1d07791eee3c3dd0955a02402b05b3a357816d8d    .github
+100644 blob 1c0a1e94b7bbdd951f456cda51af6b8484cc3cee    .gitignore
+100644 blob d10c04c6e7e0014f4fe883599c11747c15012d4e    README.md
+040000 tree 7d0898a908e274ea809722844cdbd836f3b1c05a    app
+040000 tree 6db686e340ecdd318fa43375e26254293371942a    labs
+040000 tree 3f11973a71be5915539cb53313149aa319d69cb5    lectures
+
+```
+
+Command:
+
+```bash
+git cat-file -p 1c0a1e94b7bbdd951f456cda51af6b8484cc3cee
+```
+
+Output:
+
+```bash
+ ⚠️  KEEP THIS FILE MINIMAL.
+#
+# This .gitignore is inherited by every student fork. Anything listed here
+# is something a student CANNOT `git add` without `-f`. So this file must
+# ONLY contain:
+#   (a) instructor-only paths (refs/), and
+#   (b) machine-generated junk that NOBODY should ever commit.
+#
+# Do NOT add lab DELIVERABLES here (scan reports, SBOMs, go.sum, k8s
+# manifests, CI workflows, Dockerfiles, playbooks, dashboards, …). Students
+# are told to commit those in their submission PRs — ignoring them upstream
+# silently breaks the lab. When in doubt, leave it OUT of this file.
+
+# ── Instructor-only ─────────────────────────────────────────────
+# Reference submissions (dry-run worked examples). Never pushed upstream;
+# students never see these. This is the one path that is intentionally hidden.
+refs/
+
+# ── Machine-generated junk (no one commits these) ───────────────
+# Compiled binaries / local runtime state
+app/quicknotes
+app/data/
+/quicknotes
+*.exe
+
+# Vagrant runtime state (Lab 5) — the Vagrantfile IS committed; .vagrant/ is not
+.vagrant/
+
+# Nix build symlinks (Lab 11) — flake.nix + flake.lock ARE committed; result is not
+result
+result-*
+
+# Terraform state — MUST never be committed (can contain secrets)
+*.tfstate
+*.tfstate.backup
+.terraform/
+
+# Python virtualenvs / caches
+.venv/
+__pycache__/
+*.pyc
+
+# Editor / IDE
+.vscode/
+.idea/
+*.swp
+
+# OS noise
+.DS_Store
+Thumbs.db
+
+# Local agent config (not part of the course)
+.claude/
+
+# NOTE: deliberately NOT ignored, because students commit them as lab evidence:
+#   submissions/labN.md        (lab reports)
+#   .github/workflows/*.yml    (Lab 3 CI)
+#   Dockerfile, compose.yaml   (Lab 6)
+#   ansible/                   (Lab 7)
+#   monitoring/                (Lab 8)
+#   *.sbom.cdx.json, zap-*.html/json, trivy-*.txt   (Lab 9 scan evidence)
+#   flake.nix, flake.lock      (Lab 11)
+#   wasm/main.go, spin.toml, go.sum   (Lab 12)
+
+```
+
+## 1.2 Look inside .git/
+
+Command:
+
+```bash
+ls -la .git/ 
+```
+
+Output:
+
+```bash
+total 33
+drwxr-xr-x 1 user 197121    0 Jun  9 12:45 ./
+drwxr-xr-x 1 user 197121    0 Jun  9 12:45 ../
+-rw-r--r-- 1 user 197121   74 Jun  8 22:54 COMMIT_EDITMSG
+-rw-r--r-- 1 user 197121  796 Jun  7 23:17 FETCH_HEAD
+-rw-r--r-- 1 user 197121   21 Jun  9 12:45 HEAD
+-rw-r--r-- 1 user 197121  566 Jun  8 13:29 config
+-rw-r--r-- 1 user 197121   73 Jun  7 23:13 description
+drwxr-xr-x 1 user 197121    0 Jun  7 23:13 hooks/
+-rw-r--r-- 1 user 197121 3183 Jun  9 12:45 index
+drwxr-xr-x 1 user 197121    0 Jun  7 23:13 info/
+drwxr-xr-x 1 user 197121    0 Jun  7 23:14 logs/
+drwxr-xr-x 1 user 197121    0 Jun  8 22:54 objects/
+-rw-r--r-- 1 user 197121  112 Jun  7 23:14 packed-refs
+drwxr-xr-x 1 user 197121    0 Jun  7 23:14 refs/
+
+```
+
+Command:
+
+```bash
+cat .git/HEAD
+```
+
+Output:
+
+```bash
+ref: refs/heads/main
+
+```
+
+Command:
+
+```bash
+ls .git/refs/heads/
+```
+
+Output:
+
+```bash
+feature/  main
+
+```
+
+Command:
+
+```bash
+ls .git/objects/ | head
+```
+
+Output:
+
+```bash
+02/
+0a/
+0c/
+0d/
+0e/
+0f/
+13/
+16/
+1a/
+1d/
+
+```
+
+Command:
+
+```bash
+find .git/objects -type f | wc -l
+```
+
+Output:
+
+```bash
+62
+
+```
+
+## 1.3  Simulate disaster + recover
+
+Command:
+
+```bash
+git reflog
+```
+
+Output:
+
+```bash
+f3c449b (HEAD -> feature/lab2, main) HEAD@{0}: reset: moving to HEAD~2
+e4b9102 HEAD@{1}: commit: wip(lab2): more progress
+0a54263 HEAD@{2}: commit: wip(lab2): start
+f3c449b (HEAD -> feature/lab2, main) HEAD@{3}: checkout: moving from main to feature/lab2
+f3c449b (HEAD -> feature/lab2, main) HEAD@{4}: checkout: moving from feature/lab1 to main
+
+```
+
+Command:
+
+```bash
+git reset --hard 0a54263
+```
+
+Output:
+
+```bash
+HEAD is now at 0a54263 wip(lab2): start
+
+```
+
+Command:
+
+```bash
+git reset --hard e4b9102
+```
+
+Output:
+
+```bash
+HEAD is now at e4b9102 wip(lab2): more progress
+
+```
+
+If `git gc` had run after the bad reset, Git might eventually remove unreachable commits that were no longer referenced by any branch or tag. In that case, the commits visible only through `git reflog` could disappear, making recovery much harder or impossible using normal Git commands. This is why reflog recovery should be done quickly after destructive commands like `git reset --hard`.
+
+# Task 2
+
+## 2.1: Annotated, signed release tag
+
+```bash
+git tag -v "v0.1.0-lab2-${USER}"
+```
+
+The signed tag verification output
+
+```bash
+object 0dcb25a68121f24c281348d724106ead11d1bf8d
+type commit
+tag v0.1.0-lab2-
+tagger Nikita Schankin <nikita.sshankin@gmail.com> 1781014173 +0300
+
+Lab 2 milestone — version control deep dive
+Good "git" signature for nikita.sshankin@gmail.com with ED25519 key SHA256:YmuqnukZ7Vv/dkS/udvYvJErhfCYImVdz+nMrsHdP/s
+
+```
+
+## 2.2 Rebase + force-with-lease
+
+Before:
+
+```bash
+* 745403f docs(lab2): start submission
+* e4b9102 wip(lab2): more progress
+* 0a54263 wip(lab2): start
+* f3c449b test: unsigned commit (should fail)
+* 027e77b test: signed commit (should not fail)
+* 0dcb25a (tag: v0.1.0-lab2-) docs: add PR template
+:...skipping...
+* 745403f docs(lab2): start submission
+* e4b9102 wip(lab2): more progress
+* 0a54263 wip(lab2): start
+
+```
+
+After:
+
+```bash
+* b91b8d4 (HEAD -> feature/lab2, origin/feature/lab2) docs(lab2): start submission
+* 9207a96 wip(lab2): more progress
+* 2da67d2 wip(lab2): start
+* aa19fea test: unsigned commit (should fail)
+* 92fa1a4 test: signed commit (should not fail)
+* 88bdfab (origin/main, origin/HEAD, main) docs: upstream moved while you worked
+* 0dcb25a (tag: v0.1.0-lab2-) docs: add PR template
+* 66bbd4d (upstream/main, upstream/HEAD) docs(lab1): align Task 3 GitHub Community engagement with other courses
+*   170000c Merge pull request #907 from inno-devops-labs/s26-refactor
+|\  
+| * d50436c (upstream/s26-refactor) fix(lab12,gitignore): Spin SDK
+
+```
+
+## 2.3: Document
+
+I would choose **merge** when working on a shared branch or when I want to preserve the exact history of how branches were combined. I would choose **rebase** for my own feature branch before opening a PR, because it makes the history cleaner and easier to review. In team projects, I would avoid rebasing commits that other people already use, because rewriting shared history can create confusion.
+
+# Bonus task
+
+## git bisect log
+
+```bash
+git bisect start
+# status: waiting for both good and bad commits
+# bad: [f0c9243b7c80ebb930a1ce7048a1d65b4c2ac493] docs(app): mention go test invocation
+git bisect bad f0c9243b7c80ebb930a1ce7048a1d65b4c2ac493
+# status: waiting for good commit(s), bad commit known
+# good: [0ec87b808ae6a257a98ecea4a3c8d38a7f2c5ac7] chore(app): document versioning scheme (bisect fixture baseline)
+git bisect good 0ec87b808ae6a257a98ecea4a3c8d38a7f2c5ac7
+# bad: [f285ede8611e55ac0a7d01100891c0cc775e0709] refactor(store): simplify nextID restoration in load()
+git bisect bad f285ede8611e55ac0a7d01100891c0cc775e0709
+# good: [cb89bb9ee2ee5010b166061447eaca3ae0da2378] docs(store): comment the load() decode step
+git bisect good cb89bb9ee2ee5010b166061447eaca3ae0da2378
+# first bad commit: [f285ede8611e55ac0a7d01100891c0cc775e0709] refactor(store): simplify nextID restoration in load()
+```
+
+## The offending commit's SHA + message
+
+```bash
+[f285ede8611e55ac0a7d01100891c0cc775e0709] refactor(store): simplify nextID restoration in load()
+```
+
+## Explanation
+
+Git bisect found the bug by starting with one known bad commit (HEAD) and one known good commit (v0.0.1). It then checked commits in the middle of that range and used the test command to decide whether each commit was good or bad. Because bisect uses binary search, it only needed about log₂(N) steps instead of testing every commit manually. In this case, it identified f285ede8611e55ac0a7d01100891c0cc775e0709 as the first commit where the QuickNotes store reload test started failing.