ev/internal/lg/init.go

package lg

import (
	"context"
	"log"
	"os"
	"strings"

	"go.uber.org/multierr"
)

func Init(ctx context.Context, name string) (context.Context, func(context.Context) error) {
	ctx, span := Span(ctx)
	defer span.End()

	stop := [3]func() error{
		initLogger(name),
	}
	ctx, stop[1] = initMetrics(ctx, name)
	ctx, stop[2] = initTracing(ctx, name)

	reverse(stop[:])

	return ctx, func(context.Context) error {
		log.Println("flushing logs...")
		errs := make([]error, len(stop))
		for i, fn := range stop {
			if fn != nil {
				errs[i] = fn()
			}
		}
		log.Println("all stopped.")
		return multierr.Combine(errs...)
	}
}

func env(name, defaultValue string) string {
	name = strings.TrimSpace(name)
	defaultValue = strings.TrimSpace(defaultValue)
	if v := strings.TrimSpace(os.Getenv(name)); v != "" {
		log.Println("# ", name, "=", v)
		return v
	}
	log.Println("# ", name, "=", defaultValue, "(default)")
	return defaultValue
}

type secret string

func (s secret) String() string {
	if s == "" {
		return "(nil)"
	}
	return "***"
}
func (s secret) Secret() string {
	return string(s)
}
func envSecret(name, defaultValue string) secret {
	name = strings.TrimSpace(name)
	defaultValue = strings.TrimSpace(defaultValue)
	if v := strings.TrimSpace(os.Getenv(name)); v != "" {
		log.Println("# ", name, "=", secret(v))
		return secret(v)
	}
	log.Println("# ", name, "=", secret(defaultValue), "(default)")
	return secret(defaultValue)
}