Build out all 27 modules + capstone (#1)

Co-authored-by: claude <claude@jpaul.io> Co-committed-by: claude <claude@jpaul.io>
2026-06-22 12:19:01 -04:00
parent 4bd586bbd0
commit 2684095e2f
117 changed files with 15131 additions and 1 deletions
@@ -0,0 +1,95 @@
+#!/usr/bin/env bash
+#
+# deploy.sh — the deploy step of CD, simulated with a local container run.
+#
+# The five steps of any deploy, provider-neutral (see the module README):
+#   1. build/pull the specific image tag        4. health-check before trusting it
+#   2. inject runtime config + secrets          5. cut over if healthy, ROLL BACK if not
+#   3. start the new version
+#
+# The *target* here is your own machine instead of a server, but the logic is the real thing.
+#
+# Usage:
+#   ./deploy.sh <tag>        # e.g. ./deploy.sh $(git rev-parse --short HEAD)
+#   BREAK=1 ./deploy.sh <tag># force the new version's health check to fail, to demo rollback
+#
+# Requires: docker (or `alias docker=podman`), curl.
+
+set -euo pipefail
+
+IMAGE="tasks-app"
+CONTAINER="tasks-app"
+PORT="8000"
+STATE_FILE=".deploy-state"          # records the last good tag, for rollback
+TAG="${1:-$(git rev-parse --short HEAD)}"
+
+say() { printf '\n=== %s\n' "$*"; }
+
+# --- Step 1: build the artifact for this tag (in real CD this was already built+pushed by CI) -----
+say "Building ${IMAGE}:${TAG}"
+docker build -t "${IMAGE}:${TAG}" .
+
+# Remember what is currently running so we can roll back to it.
+PREVIOUS=""
+if [ -f "${STATE_FILE}" ]; then
+  PREVIOUS="$(cat "${STATE_FILE}")"
+fi
+
+# --- Steps 2 + 3: start the new version with runtime config/secrets injected (Module 17) ----------
+# Note: APP_VERSION is config supplied at run time, NOT baked into the image. A real deploy would
+# also pass secrets here (e.g. --env-file, a mounted secret, or a secrets-manager lookup) — never
+# committed, never in the image.
+start_version() {
+  local tag="$1"
+  docker rm -f "${CONTAINER}" >/dev/null 2>&1 || true
+  docker run -d --name "${CONTAINER}" \
+    -p "${PORT}:8000" \
+    -e "APP_VERSION=${tag}" \
+    ${BREAK:+-e "BREAK=${BREAK}"} \
+    "${IMAGE}:${tag}" >/dev/null
+}
+
+say "Starting ${IMAGE}:${TAG}"
+start_version "${TAG}"
+
+# --- Step 4: health-check the new version before trusting it --------------------------------------
+healthy() {
+  for _ in $(seq 1 10); do
+    if curl -fs "http://localhost:${PORT}/health" >/dev/null 2>&1; then
+      return 0
+    fi
+    sleep 1
+  done
+  return 1
+}
+
+say "Health-checking http://localhost:${PORT}/health"
+if healthy; then
+  # --- Step 5a: cut over. Record this as the new known-good for the next deploy's rollback target.
+  echo "${TAG}" > "${STATE_FILE}"
+  say "DEPLOY OK — ${IMAGE}:${TAG} is live and healthy"
+  curl -s "http://localhost:${PORT}/health"; echo
+  exit 0
+fi
+
+# --- Step 5b: ROLLBACK. The new version failed its health check. ----------------------------------
+say "HEALTH CHECK FAILED for ${IMAGE}:${TAG} — rolling back"
+docker rm -f "${CONTAINER}" >/dev/null 2>&1 || true
+
+if [ -z "${PREVIOUS}" ]; then
+  echo "No previous known-good version to roll back to. Service is DOWN." >&2
+  echo "(Deploy a healthy version first, then re-run the BREAK=1 deploy to see rollback work.)" >&2
+  exit 1
+fi
+
+# Rollback is trivial because we deploy immutable tags: just run the old one again. No rebuild.
+say "Restoring previous good version ${IMAGE}:${PREVIOUS}"
+BREAK="" start_version "${PREVIOUS}"     # clear BREAK so the good version comes up clean
+if healthy; then
+  say "ROLLED BACK — ${IMAGE}:${PREVIOUS} is live and healthy. The bad deploy reverted itself."
+  curl -s "http://localhost:${PORT}/health"; echo
+  exit 1   # exit non-zero: the deploy you asked for did NOT ship, even though service recovered
+else
+  echo "Rollback FAILED — service is DOWN. Investigate ${IMAGE}:${PREVIOUS}." >&2
+  exit 2
+fi