shopdb-flask/scripts/backup/backup.sh

#!/usr/bin/env bash
# ShopDB backup one-shot.
#
# Produces one recoverable set per run and stores it two ways: a plain
# db.sql.gz + manifest.json on the local /backups volume for a fast, repo-free
# restore, and a restic snapshot (db dump + instance tree + manifest) at
# RESTIC_REPOSITORY for a deduped, encrypted, offsite copy.
#
# Sequence:
#   1. mysqldump --single-transaction (InnoDB-consistent, non-blocking)
#   2. manifest.py stamps core+plugin Alembic revisions + image tag
#   3. restic backup the dump + /app/instance + manifest as ONE snapshot
#   4. restic forget --keep-daily 5 --keep-weekly 4 --keep-monthly 6 --prune
#   5. restic check - fail loudly if the repo is unhealthy, so a bad repo is
#      caught on backup night, not restore night.
#
# ASCII only, no emojis - matches the repo style gate.
set -euo pipefail

BACKUPS_ROOT="${SHOPDB_BACKUPS_ROOT:-/backups}"
SITE="${SHOPDB_SITE:-shopdb}"
STAMP="$(date -u +%Y-%m-%dT%H%M%SZ)"
SETNAME="${SITE}-${STAMP}"
SETDIR="${BACKUPS_ROOT}/${SETNAME}"

# shellcheck source=scripts/backup/status.sh
. /opt/backup/status.sh

log() { echo "[backup] $*"; }

# Record the run outcome on any exit so a failed backup is visible in the UI
# history, not just a silent gap.
BACKUP_DONE=false
_on_exit() {
	code=$?
	if [ "${BACKUP_DONE}" = true ]; then
		status_write backup done "${SETNAME}" "Backup complete"
		history_append backup success "${SETNAME}" "Backup complete"
	else
		status_write backup failed "${SETNAME}" "Backup failed (exit ${code})"
		history_append backup failed "${SETNAME}" "Backup failed (exit ${code})"
	fi
}
trap _on_exit EXIT

mkdir -p "${SETDIR}"
status_write backup database "${SETNAME}" "Dumping database"

# 1. Database: whole-DB logical dump, consistent and non-blocking on InnoDB.
log "dumping database ${MYSQL_DATABASE} from ${MYSQL_HOST}"
mysqldump \
	--host="${MYSQL_HOST}" \
	--user="${MYSQL_USER}" \
	--password="${MYSQL_PASSWORD}" \
	--single-transaction \
	--routines \
	--triggers \
	--databases "${MYSQL_DATABASE}" \
	| gzip -c > "${SETDIR}/db.sql.gz"
log "database dump written ($(du -h "${SETDIR}/db.sql.gz" | cut -f1))"

# 2. Manifest: the schema stamp that makes a restore a checked operation.
# Capture the revision actually applied to the DATABASE (its alembic_version),
# not just the code head. A restore must gate on the DATA revision; stamping
# only the code head hides an image that has outrun its own database and lets a
# behind-schema dump restore under ahead-schema code (1054 Unknown column on
# every affected table). Query it straight from the dumped DB.
log "reading applied database revision (alembic_version)"
DATAREV="$(mysql \
	--host="${MYSQL_HOST}" \
	--user="${MYSQL_USER}" \
	--password="${MYSQL_PASSWORD}" \
	--skip-column-names --batch \
	-e "SELECT version_num FROM alembic_version LIMIT 1;" \
	"${MYSQL_DATABASE}" 2>/dev/null | tr -d '\r')"
[ -n "${DATAREV}" ] || log "WARN could not read alembic_version - datarev will be empty"

log "writing manifest"
# Manifest generation requires Python. If not available (offline build), create
# a minimal manifest with just the essentials for restore identification.
if command -v python3 >/dev/null 2>&1; then
	python3 /opt/backup/manifest.py \
		--out "${SETDIR}/manifest.json" \
		--takenat "${STAMP}" \
		--site "${SITE}" \
		--imagetag "${SHOPDB_IMAGE_TAG:-source}" \
		--datarev "${DATAREV}" \
		--migrations /app/migrations \
		--plugins /app/plugins

	# Consistency guard: if the DATA revision does not match the CODE head, this
	# backup captures a database the running image has outrun. It is still stored
	# (losing it would be worse) but flagged loudly so a restore of it is a
	# deliberate choice, not a surprise.
	CODEREV="$(python3 -c \
		'import json,sys;print(",".join(sorted(json.load(open(sys.argv[1]))["schemarev"]["core"])))' \
		"${SETDIR}/manifest.json" 2>/dev/null || echo "")"
	if [ -n "${DATAREV}" ] && [ "${DATAREV}" != "${CODEREV}" ]; then
		log "WARN schema drift: database is at '${DATAREV}' but code head is '${CODEREV}'"
		log "WARN this DB has not run 'flask db upgrade' to the running image; restore will upgrade it"
		history_append backup warning "${SETNAME}" "Schema drift: data ${DATAREV} vs code ${CODEREV}"
	fi
else
	# No Python available - create minimal manifest with bash
	log "Python not available - creating minimal manifest"
	cat > "${SETDIR}/manifest.json" <<-EOF
	{
	  "takenat": "${STAMP}",
	  "site": "${SITE}",
	  "imagetag": "${SHOPDB_IMAGE_TAG:-source}",
	  "datarev": "${DATAREV}",
	  "note": "Minimal manifest - Python not available in offline build"
	}
	EOF
fi

# 3. restic snapshot: db dump + instance tree + manifest, one point in time.
#    Skips gracefully when restic/repo are not configured (local-only sites).
IS_CHECK_PASSED=false
status_write backup snapshot "${SETNAME}" "Snapshotting to backup store"
if command -v restic >/dev/null 2>&1 && [ -n "${RESTIC_REPOSITORY:-}" ]; then
	if ! restic snapshots >/dev/null 2>&1; then
		log "initializing restic repository at ${RESTIC_REPOSITORY}"
		restic init
	fi
	log "restic backup (db dump + instance tree + manifest)"
	restic backup \
		--tag "${SITE}" \
		--tag "${SETNAME}" \
		"${SETDIR}/db.sql.gz" \
		"${SETDIR}/manifest.json" \
		/app/instance

	# 4. Retention: any day in the last 5, plus weekly/monthly tail.
	log "pruning per retention policy"
	restic forget \
		--tag "${SITE}" \
		--keep-daily 5 \
		--keep-weekly 4 \
		--keep-monthly 6 \
		--prune

	# 5. Integrity: learn about corruption now, not at restore time.
	log "verifying repository integrity"
	if restic check; then
		IS_CHECK_PASSED=true
		log "restic check passed"
	else
		log "restic check FAILED - repository may be corrupt"
	fi
else
	log "restic not configured - local db.sql.gz + manifest only"
fi

# Record the verification result into the manifest so the UI can badge the set.
if command -v python3 >/dev/null 2>&1; then
	python3 /opt/backup/manifest.py \
		--amend "${SETDIR}/manifest.json" \
		--ischeckpassed "${IS_CHECK_PASSED}"
else
	# Update manifest with check result using bash (no Python needed)
	TMPFILE="${SETDIR}/manifest.json.tmp"
	cat "${SETDIR}/manifest.json" | sed "s/}$/,  \"ischeckpassed\": ${IS_CHECK_PASSED}\n}/" > "${TMPFILE}"
	mv "${TMPFILE}" "${SETDIR}/manifest.json"
fi

# Clear the request sentinel the UI drops when an operator clicks "Back up now".
rm -f "${BACKUPS_ROOT}/.backup-requested" 2>/dev/null || true

BACKUP_DONE=true
log "backup set ${SETNAME} complete"