Add scripts/postgres_backup.sh

scripts/postgres_backup.sh

@@ -0,0 +1,90 @@
+#!/usr/bin/env bash
+#
+# Create a compressed PostgreSQL backup and remove old backup files.
+#
+# Required environment variables:
+#   PGHOST       PostgreSQL host.
+#   PGUSER       PostgreSQL user.
+#   PGPASSWORD   PostgreSQL password.
+#   PGDATABASE   Database name to back up.
+#
+# Usage:
+#   PGHOST=localhost PGUSER=app PGPASSWORD=secret PGDATABASE=appdb \
+#     bash postgres_backup.sh --destination /backups/postgres
+#
+# Options:
+#   --destination DIR   Backup directory. Default: ./backups
+#   --retention-days N  Delete backups older than N days. Default: 14.
+#   --help              Show this help message.
+
+set -Eeuo pipefail
+
+destination="./backups"
+retention_days="14"
+
+usage() {
+  sed -n '2,24p' "$0" | sed 's/^# \{0,1\}//'
+}
+
+log() {
+  printf '[%s] %s\n' "$(date -Is)" "$*"
+}
+
+require_env() {
+  local name="$1"
+  if [[ -z "${!name:-}" ]]; then
+    printf 'ERROR: required environment variable is missing: %s\n' "$name" >&2
+    exit 1
+  fi
+}
+
+while [[ "$#" -gt 0 ]]; do
+  case "$1" in
+    --destination)
+      destination="${2:-}"
+      [[ -n "$destination" ]] || { printf 'ERROR: --destination requires a directory.\n' >&2; exit 1; }
+      shift 2
+      ;;
+    --retention-days)
+      retention_days="${2:-}"
+      [[ "$retention_days" =~ ^[0-9]+$ ]] || { printf 'ERROR: retention must be a positive integer.\n' >&2; exit 1; }
+      shift 2
+      ;;
+    --help|-h)
+      usage
+      exit 0
+      ;;
+    *)
+      printf 'ERROR: unknown option: %s\n' "$1" >&2
+      usage >&2
+      exit 1
+      ;;
+  esac
+done
+
+command -v pg_dump >/dev/null 2>&1 || { printf 'ERROR: pg_dump command not found.\n' >&2; exit 1; }
+command -v gzip >/dev/null 2>&1 || { printf 'ERROR: gzip command not found.\n' >&2; exit 1; }
+
+require_env PGHOST
+require_env PGUSER
+require_env PGPASSWORD
+require_env PGDATABASE
+
+mkdir -p "$destination"
+
+timestamp="$(date +%Y%m%d-%H%M%S)"
+backup_file="${destination}/${PGDATABASE}-${timestamp}.sql.gz"
+
+log "Starting PostgreSQL backup for database '${PGDATABASE}'."
+pg_dump --format=plain --no-owner --no-privileges "$PGDATABASE" | gzip -9 > "$backup_file"
+
+if [[ ! -s "$backup_file" ]]; then
+  printf 'ERROR: backup file was not created or is empty: %s\n' "$backup_file" >&2
+  exit 1
+fi
+
+log "Backup created: ${backup_file}"
+log "Removing backups older than ${retention_days} days from ${destination}."
+find "$destination" -type f -name "${PGDATABASE}-*.sql.gz" -mtime "+${retention_days}" -print -delete
+log "Backup job completed successfully."
+