backup.sh

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Purpose

Create PostgreSQL backups using pg_dump with custom or plain formats.

Location

databases/postgres/backup.sh

Preconditions

  • Required tools: bash, pg_dump
  • Required permissions: PostgreSQL connect and read privileges for target database
  • Required environment variables: optional PGPASSWORD for non-interactive auth

Arguments

Flag Required Default Description
--host HOST No localhost PostgreSQL host
--port PORT No 5432 PostgreSQL port
--user USER Yes N/A Database user
--database NAME Yes N/A Database to back up
--output-file PATH Yes N/A Backup file path
--format FORMAT No custom custom\|plain
--compress-level N No 6 Compression level for custom format
--dry-run No false Print command only

Scenarios

  • Happy path: create compressed custom archive for routine backups.
  • Common operational path: export plain SQL for migration handoff.
  • Failure path: missing privileges or invalid output path.
  • Recovery/rollback path: fix auth/path and rerun backup.

Usage

databases/postgres/backup.sh --user app --database appdb --output-file /tmp/appdb.dump
databases/postgres/backup.sh --user app --database appdb --output-file /tmp/appdb.sql --format plain

Behavior

  • Main execution flow:
  • validates required parameters
  • builds pg_dump command according to selected format
  • executes or prints in dry-run mode
  • Idempotency notes: repeatable; creates/overwrites backup file.
  • Side effects: writes backup artifact.

Output

  • Standard output format: pg_dump output/logs.
  • Exit codes:
  • 0 success
  • 2 argument/prerequisite errors
  • non-zero on dump/auth/runtime errors

Failure Modes

  • Common errors and likely causes:
  • auth failure for supplied user
  • inaccessible host/port
  • write permission denied on output path
  • Recovery and rollback steps:
  • verify credentials and network access
  • ensure destination directory is writable
  • rerun with corrected arguments

Security Notes

  • Secret handling: passwords should come from env/secure auth methods, not flags.
  • Least-privilege requirements: read access only for target database.
  • Audit/logging expectations: backup runs should be tracked by schedule/ticket.

Testing

  • Unit tests:
  • format/argument validation
  • Integration tests:
  • backup non-production database in both formats
  • Manual verification:
  • inspect backup file and run a test restore
cluster-healthcheck.sh restore.sh