5.8 Reading arguments and a full sample script

#!/usr/bin/env bash
set -euo pipefail

DRY_RUN=0
APP_URL="${APP_URL:-http://localhost:8080/health}"
SERVICE_NAME="${SERVICE_NAME:-badge-api}"
LOG_DIR="${HOME}/badge-api-logs"

for arg in "$@"; do
  case "$arg" in
    --dry-run) DRY_RUN=1 ;;
    --url=*) APP_URL="${arg#*=}" ;;
    *) echo "Unknown arg: $arg" >&2; exit 2 ;;
  esac
done

mkdir -p "$LOG_DIR"
ts="$(date -Iseconds)"

if curl -fsS "$APP_URL" >/dev/null; then
  echo "$ts OK $APP_URL" | tee -a "$LOG_DIR/health.log"
  exit 0
fi

echo "$ts FAIL $APP_URL" | tee -a "$LOG_DIR/health.log"

if [[ "$DRY_RUN" -eq 1 ]]; then
  echo "DRY-RUN: would restart $SERVICE_NAME"
  exit 1
fi

sudo systemctl restart "$SERVICE_NAME"
sleep 2
curl -fsS "$APP_URL" >/dev/null
echo "$ts RESTARTED_OK $SERVICE_NAME" | tee -a "$LOG_DIR/health.log"