Promote MongoDB backup rehearsal

.github/workflows/ci.yml

@@ -24,6 +24,9 @@ jobs:
       - name: Validate CodeQL branch coverage
         run: scripts/test-codeql-branches.sh
 
+      - name: Rehearse MongoDB backup and restore scripts
+        run: scripts/test-mongo-backup-restore.sh
+
   server:
     name: Server lint and unit tests
     runs-on: ubuntu-latest

docs/operations.md

@@ -131,6 +131,7 @@ The deploy script can be tested without production access:
 ```sh
 scripts/test-deploy-classifier.sh
 scripts/test-deploy.sh
+scripts/test-mongo-backup-restore.sh
 scripts/classify-deploy-target.sh client/src/components/App.jsx
 ```
 

scripts/test-mongo-backup-restore.sh

@@ -0,0 +1,141 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+log_command() {
+  local command="$1"
+  shift
+
+  {
+    printf '%s' "$command"
+    printf ' %q' "$@"
+    printf '\n'
+  } >> "$MONGO_REHEARSAL_LOG"
+}
+
+fake_docker() {
+  log_command docker "$@"
+
+  if [ "$1" != "compose" ]; then
+    echo "Unexpected fake docker command: $*" >&2
+    return 1
+  fi
+
+  if [[ "$*" == *mongodump* ]]; then
+    printf 'synthetic-mongo-archive'
+    return 0
+  fi
+
+  if [[ "$*" == *mongorestore* ]]; then
+    printf 'restore-input-bytes=%s\n' "$(wc -c)" >> "$MONGO_REHEARSAL_LOG"
+    return 0
+  fi
+
+  echo "Unexpected fake Docker Compose command: $*" >&2
+  return 1
+}
+
+case "$(basename -- "$0")" in
+  docker)
+    fake_docker "$@"
+    exit
+    ;;
+esac
+
+SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+BACKUP_SCRIPT="$SCRIPT_DIR/backup-mongo.sh"
+RESTORE_SCRIPT="$SCRIPT_DIR/restore-mongo.sh"
+TEST_ROOT="$(mktemp -d "${TMPDIR:-/tmp}/letscube-mongo-rehearsal.XXXXXX")"
+
+cleanup() {
+  rm -rf -- "$TEST_ROOT"
+}
+
+trap cleanup EXIT
+
+FAKE_BIN="$TEST_ROOT/bin"
+mkdir -p "$FAKE_BIN"
+ln -s "$SCRIPT_DIR/test-mongo-backup-restore.sh" "$FAKE_BIN/docker"
+
+assert_contains() {
+  local value="$1"
+  local expected="$2"
+
+  if [[ "$value" != *"$expected"* ]]; then
+    echo "Expected output to contain: $expected" >&2
+    exit 1
+  fi
+}
+
+run_backup_test() {
+  local scenario="$TEST_ROOT/backup"
+  local backup_dir="$scenario/backups"
+  local log="$scenario/commands.log"
+  local output="$scenario/output.log"
+  local backup_path
+
+  mkdir -p "$scenario/app"
+
+  PATH="$FAKE_BIN:$PATH" \
+    APP_DIR="$scenario/app" \
+    BACKUP_DIR="$backup_dir" \
+    MONGO_BACKUP_URI="mongodb://mongo:27017/letscube" \
+    MONGO_REHEARSAL_LOG="$log" \
+    bash "$BACKUP_SCRIPT" > "$output"
+
+  backup_path="$(find "$backup_dir" -type f -name 'letscube-mongo-daily-*.archive.gz' -print -quit)"
+  if [ ! -f "$backup_path" ]; then
+    echo 'Backup script did not create a daily archive.' >&2
+    exit 1
+  fi
+
+  if [ "$(<"$backup_path")" != 'synthetic-mongo-archive' ]; then
+    echo 'Backup archive did not contain the synthetic Mongo dump.' >&2
+    exit 1
+  fi
+
+  assert_contains "$(<"$output")" 'Created MongoDB backup:'
+  assert_contains "$(<"$log")" 'mongodump'
+  assert_contains "$(<"$log")" 'MONGO_BACKUP_URI=mongodb://mongo:27017/letscube'
+}
+
+run_restore_test() {
+  local scenario="$TEST_ROOT/restore"
+  local archive="$scenario/backup.archive.gz"
+  local log="$scenario/commands.log"
+  local output="$scenario/output.log"
+
+  mkdir -p "$scenario/app"
+  printf 'synthetic restore archive' > "$archive"
+
+  if printf 'NO\n' | PATH="$FAKE_BIN:$PATH" \
+    APP_DIR="$scenario/app" \
+    MONGO_BACKUP_URI="mongodb://mongo:27017/letscube" \
+    MONGO_REHEARSAL_LOG="$log" \
+    bash "$RESTORE_SCRIPT" "$archive" > "$output"; then
+    echo 'Restore accepted an invalid confirmation.' >&2
+    exit 1
+  fi
+
+  if [ -e "$log" ]; then
+    echo 'Restore invoked Docker before receiving the required confirmation.' >&2
+    exit 1
+  fi
+
+  printf 'RESTORE\n' | PATH="$FAKE_BIN:$PATH" \
+    APP_DIR="$scenario/app" \
+    MONGO_BACKUP_URI="mongodb://mongo:27017/letscube" \
+    MONGO_REHEARSAL_LOG="$log" \
+    bash "$RESTORE_SCRIPT" "$archive" > "$output"
+
+  assert_contains "$(<"$output")" 'MongoDB restore completed.'
+  assert_contains "$(<"$log")" 'mongorestore'
+  assert_contains "$(<"$log")" '--drop'
+  assert_contains "$(<"$log")" '--archive'
+  assert_contains "$(<"$log")" '--gzip'
+  assert_contains "$(<"$log")" 'restore-input-bytes=25'
+}
+
+run_backup_test
+run_restore_test
+
+echo 'MongoDB backup and restore rehearsal checks passed.'