healthcheck.sh

Previous Next

Purpose

Validate MySQL service reachability and optional query execution readiness.

Location

databases/mysql/healthcheck.sh

Preconditions

  • Required tools: bash
  • Required permissions: DB login rights for supplied user
  • Required environment variables: optional MYSQL_PWD for auth

Arguments

Flag Required Default Description
--host HOST No localhost MySQL host
--port PORT No 3306 MySQL port
--user USER Yes N/A Database user
--database NAME No none Optional DB for query check
--strict No false WARN treated as failure
--json No false JSON report output

Scenarios

  • Happy path: ping and optional query checks pass.
  • Common operational path: run in deployment health gates.
  • Failure path: MySQL unreachable or auth failure.
  • Recovery/rollback path: fix connectivity/credentials and rerun.

Usage

databases/mysql/healthcheck.sh --user app --json
databases/mysql/healthcheck.sh --user app --database appdb --strict

Behavior

  • Main execution flow:
  • validates input user
  • checks availability of mysqladmin and mysql
  • runs ping check and optional SELECT 1 query
  • emits PASS/WARN/FAIL summary
  • Idempotency notes: read-only checks.
  • Side effects: none.

Output

  • Standard output format: table summary (default) or JSON.
  • Exit codes:
  • 0 healthy (and no warnings in strict mode)
  • 1 failures detected (or warnings in strict mode)
  • 2 invalid arguments

Failure Modes

  • Common errors and likely causes:
  • missing client tools
  • host/port unreachable
  • insufficient DB privileges
  • Recovery and rollback steps:
  • install required tools
  • verify network access and authentication
  • confirm user privileges for query checks

Security Notes

  • Secret handling: credentials should be sourced from secure env management.
  • Least-privilege requirements: read-only permissions for health checks.
  • Audit/logging expectations: healthcheck runs should be included in operational evidence.

Testing

  • Unit tests:
  • strict/json and argument validation
  • Integration tests:
  • run against healthy/unhealthy test endpoints
  • Manual verification:
  • compare output with direct mysqladmin/mysql commands
restore.sh branch-create.sh