JSON Line Printer

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

events=(
	"signup:3"
	"lesson_view:18"
	"challenge_passed:7"
)

created_at="$(date -u +%Y-%m-%dT%H:%M:%SZ)"

for row in "${events[@]}"; do
	IFS=: read -r event count <<< "$row"
	printf '{"event":"%s","count":%d,"created_at":"%s"}\n' \
		"$event" "$count" "$created_at"
done