textmachine/platform/internal/config/config.go

81 lines
2.4 KiB
Go

// Package config reads the service's settings from the environment.
package config
import (
"fmt"
"os"
"strings"
"time"
)
// Config is the whole configuration surface. Environment only: a control plane is deployed, not
// hand-run, and a settings file is one more thing to keep in sync with the deployment.
type Config struct {
Addr string
// DSN is the Postgres connection string. Empty is allowed and means "start unready": the
// service answers liveness and reports on /readyz why it cannot serve.
//
// ⚠ It carries a password. It is read from the environment, never logged, and never echoed
// into an error message.
DSN string
// TrustedOrigins are origins besides our own that may make unsafe requests.
TrustedOrigins []string
// SessionIdleTTL is how long a session survives without use; SessionMaxAge is the ceiling no
// amount of use can extend.
SessionIdleTTL time.Duration
SessionMaxAge time.Duration
// Migrate applies pending migrations at boot. Off by default: a rollout should migrate once,
// deliberately, not once per replica.
Migrate bool
}
// Load reads the environment.
func Load() (Config, error) {
c := Config{
Addr: env("TM_PLATFORM_ADDR", "127.0.0.1:8080"),
DSN: os.Getenv("TM_PLATFORM_DSN"),
SessionIdleTTL: 14 * 24 * time.Hour,
SessionMaxAge: 90 * 24 * time.Hour,
Migrate: os.Getenv("TM_PLATFORM_MIGRATE") == "1",
}
if raw := os.Getenv("TM_PLATFORM_TRUSTED_ORIGINS"); raw != "" {
for _, o := range strings.Split(raw, ",") {
if o = strings.TrimSpace(o); o != "" {
c.TrustedOrigins = append(c.TrustedOrigins, o)
}
}
}
var err error
if c.SessionIdleTTL, err = duration("TM_PLATFORM_SESSION_IDLE", c.SessionIdleTTL); err != nil {
return Config{}, err
}
if c.SessionMaxAge, err = duration("TM_PLATFORM_SESSION_MAX_AGE", c.SessionMaxAge); err != nil {
return Config{}, err
}
if c.SessionIdleTTL > c.SessionMaxAge {
return Config{}, fmt.Errorf("config: session idle TTL %s exceeds max age %s", c.SessionIdleTTL, c.SessionMaxAge)
}
return c, nil
}
func env(key, def string) string {
if v := os.Getenv(key); v != "" {
return v
}
return def
}
func duration(key string, def time.Duration) (time.Duration, error) {
raw := os.Getenv(key)
if raw == "" {
return def, nil
}
d, err := time.ParseDuration(raw)
if err != nil {
return 0, fmt.Errorf("config: %s: %w", key, err)
}
if d <= 0 {
return 0, fmt.Errorf("config: %s must be positive", key)
}
return d, nil
}