Add config package: TOML loading with env overrides

- Base type with standard sections (Server, Database, MCIAS, Log)
- Duration wrapper type for TOML string→time.Duration decoding
- Generic Load[T] with TOML parse, reflection-based env overrides,
  defaults, required field validation, optional Validator interface
- Env overrides: PREFIX_SECTION_FIELD for string, duration, bool,
  []string (comma-separated)
- WebConfig exported for services with web UIs (not embedded in Base)
- 16 tests covering full/minimal configs, defaults, env overrides,
  validation, error cases

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-03-25 15:06:45 -07:00
parent 38da2e9a4b
commit 96d420ac82
6 changed files with 754 additions and 20 deletions

403
config/config_test.go Normal file
View File

@@ -0,0 +1,403 @@
package config
import (
"fmt"
"os"
"path/filepath"
"testing"
"time"
)
// testConfig embeds Base and adds a service-specific section.
type testConfig struct {
Base
MyService myServiceConfig `toml:"my_service"`
}
type myServiceConfig struct {
Name string `toml:"name"`
Enabled bool `toml:"enabled"`
Items []string `toml:"items"`
}
// validatingConfig implements the Validator interface.
type validatingConfig struct {
Base
Custom customSection `toml:"custom"`
}
type customSection struct {
Required string `toml:"required"`
}
func (c *validatingConfig) Validate() error {
if c.Custom.Required == "" {
return fmt.Errorf("custom.required is missing")
}
return nil
}
const minimalTOML = `
[server]
listen_addr = ":8443"
tls_cert = "/tmp/cert.pem"
tls_key = "/tmp/key.pem"
[database]
path = "/tmp/test.db"
[mcias]
server_url = "https://mcias.example.com"
service_name = "test"
[log]
level = "debug"
`
const fullTOML = `
[server]
listen_addr = ":8443"
tls_cert = "/tmp/cert.pem"
tls_key = "/tmp/key.pem"
grpc_addr = ":9443"
read_timeout = "10s"
write_timeout = "15s"
idle_timeout = "60s"
shutdown_timeout = "30s"
[database]
path = "/tmp/test.db"
[mcias]
server_url = "https://mcias.example.com"
ca_cert = "/tmp/ca.pem"
service_name = "myservice"
tags = ["env:test", "tier:dev"]
[log]
level = "warn"
[my_service]
name = "hello"
enabled = true
items = ["a", "b", "c"]
`
func writeTOML(t *testing.T, content string) string {
t.Helper()
dir := t.TempDir()
path := filepath.Join(dir, "test.toml")
if err := os.WriteFile(path, []byte(content), 0600); err != nil {
t.Fatalf("write config: %v", err)
}
return path
}
func TestLoadMinimal(t *testing.T) {
path := writeTOML(t, minimalTOML)
cfg, err := Load[testConfig](path, "TEST")
if err != nil {
t.Fatalf("Load: %v", err)
}
if cfg.Server.ListenAddr != ":8443" {
t.Fatalf("ListenAddr = %q, want %q", cfg.Server.ListenAddr, ":8443")
}
if cfg.Log.Level != "debug" {
t.Fatalf("Log.Level = %q, want %q", cfg.Log.Level, "debug")
}
if cfg.MCIAS.ServerURL != "https://mcias.example.com" {
t.Fatalf("MCIAS.ServerURL = %q", cfg.MCIAS.ServerURL)
}
}
func TestLoadFull(t *testing.T) {
path := writeTOML(t, fullTOML)
cfg, err := Load[testConfig](path, "TEST")
if err != nil {
t.Fatalf("Load: %v", err)
}
if cfg.Server.GRPCAddr != ":9443" {
t.Fatalf("GRPCAddr = %q, want %q", cfg.Server.GRPCAddr, ":9443")
}
if cfg.Server.ReadTimeout.Duration != 10*time.Second {
t.Fatalf("ReadTimeout = %v, want 10s", cfg.Server.ReadTimeout)
}
if cfg.Server.WriteTimeout.Duration != 15*time.Second {
t.Fatalf("WriteTimeout = %v, want 15s", cfg.Server.WriteTimeout)
}
if cfg.MCIAS.CACert != "/tmp/ca.pem" {
t.Fatalf("CACert = %q", cfg.MCIAS.CACert)
}
if len(cfg.MCIAS.Tags) != 2 {
t.Fatalf("Tags = %v, want 2 items", cfg.MCIAS.Tags)
}
if cfg.MyService.Name != "hello" {
t.Fatalf("MyService.Name = %q, want %q", cfg.MyService.Name, "hello")
}
if !cfg.MyService.Enabled {
t.Fatal("MyService.Enabled = false, want true")
}
if len(cfg.MyService.Items) != 3 {
t.Fatalf("MyService.Items = %v, want 3 items", cfg.MyService.Items)
}
}
func TestDefaults(t *testing.T) {
path := writeTOML(t, minimalTOML)
cfg, err := Load[testConfig](path, "TEST")
if err != nil {
t.Fatalf("Load: %v", err)
}
if cfg.Server.ReadTimeout.Duration != 30*time.Second {
t.Fatalf("ReadTimeout = %v, want 30s (default)", cfg.Server.ReadTimeout)
}
if cfg.Server.WriteTimeout.Duration != 30*time.Second {
t.Fatalf("WriteTimeout = %v, want 30s (default)", cfg.Server.WriteTimeout)
}
if cfg.Server.IdleTimeout.Duration != 120*time.Second {
t.Fatalf("IdleTimeout = %v, want 120s (default)", cfg.Server.IdleTimeout)
}
if cfg.Server.ShutdownTimeout.Duration != 60*time.Second {
t.Fatalf("ShutdownTimeout = %v, want 60s (default)", cfg.Server.ShutdownTimeout)
}
}
func TestDefaultsNotOverrideExplicit(t *testing.T) {
path := writeTOML(t, fullTOML)
cfg, err := Load[testConfig](path, "TEST")
if err != nil {
t.Fatalf("Load: %v", err)
}
// fullTOML sets read_timeout = "10s"; default is 30s.
if cfg.Server.ReadTimeout.Duration != 10*time.Second {
t.Fatalf("ReadTimeout = %v, want 10s (explicit, not default)", cfg.Server.ReadTimeout)
}
}
func TestDefaultLogLevel(t *testing.T) {
toml := `
[server]
listen_addr = ":8443"
tls_cert = "/tmp/cert.pem"
tls_key = "/tmp/key.pem"
[database]
path = "/tmp/test.db"
[mcias]
server_url = "https://mcias.example.com"
`
path := writeTOML(t, toml)
cfg, err := Load[testConfig](path, "TEST")
if err != nil {
t.Fatalf("Load: %v", err)
}
if cfg.Log.Level != "info" {
t.Fatalf("Log.Level = %q, want %q (default)", cfg.Log.Level, "info")
}
}
func TestMissingRequiredField(t *testing.T) {
tests := []struct {
name string
toml string
}{
{
"missing listen_addr",
`[server]
tls_cert = "/tmp/cert.pem"
tls_key = "/tmp/key.pem"
[database]
path = "/tmp/test.db"`,
},
{
"missing tls_cert",
`[server]
listen_addr = ":8443"
tls_key = "/tmp/key.pem"
[database]
path = "/tmp/test.db"`,
},
{
"missing tls_key",
`[server]
listen_addr = ":8443"
tls_cert = "/tmp/cert.pem"
[database]
path = "/tmp/test.db"`,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
path := writeTOML(t, tt.toml)
_, err := Load[testConfig](path, "TEST")
if err == nil {
t.Fatal("expected error for missing required field")
}
})
}
}
func TestEnvOverrideString(t *testing.T) {
path := writeTOML(t, minimalTOML)
t.Setenv("TEST_SERVER_LISTEN_ADDR", ":9999")
cfg, err := Load[testConfig](path, "TEST")
if err != nil {
t.Fatalf("Load: %v", err)
}
if cfg.Server.ListenAddr != ":9999" {
t.Fatalf("ListenAddr = %q, want %q (from env)", cfg.Server.ListenAddr, ":9999")
}
}
func TestEnvOverrideDuration(t *testing.T) {
path := writeTOML(t, minimalTOML)
t.Setenv("TEST_SERVER_READ_TIMEOUT", "5s")
cfg, err := Load[testConfig](path, "TEST")
if err != nil {
t.Fatalf("Load: %v", err)
}
if cfg.Server.ReadTimeout.Duration != 5*time.Second {
t.Fatalf("ReadTimeout = %v, want 5s (from env)", cfg.Server.ReadTimeout)
}
}
func TestEnvOverrideSlice(t *testing.T) {
path := writeTOML(t, minimalTOML)
t.Setenv("TEST_MCIAS_TAGS", "env:prod, tier:api")
cfg, err := Load[testConfig](path, "TEST")
if err != nil {
t.Fatalf("Load: %v", err)
}
if len(cfg.MCIAS.Tags) != 2 {
t.Fatalf("Tags = %v, want 2 items", cfg.MCIAS.Tags)
}
if cfg.MCIAS.Tags[0] != "env:prod" {
t.Fatalf("Tags[0] = %q, want %q", cfg.MCIAS.Tags[0], "env:prod")
}
if cfg.MCIAS.Tags[1] != "tier:api" {
t.Fatalf("Tags[1] = %q, want %q", cfg.MCIAS.Tags[1], "tier:api")
}
}
func TestEnvOverrideServiceSpecific(t *testing.T) {
path := writeTOML(t, fullTOML)
t.Setenv("TEST_MY_SERVICE_NAME", "overridden")
cfg, err := Load[testConfig](path, "TEST")
if err != nil {
t.Fatalf("Load: %v", err)
}
if cfg.MyService.Name != "overridden" {
t.Fatalf("MyService.Name = %q, want %q (from env)", cfg.MyService.Name, "overridden")
}
}
func TestEnvOverrideBool(t *testing.T) {
path := writeTOML(t, minimalTOML)
t.Setenv("TEST_MY_SERVICE_ENABLED", "true")
cfg, err := Load[testConfig](path, "TEST")
if err != nil {
t.Fatalf("Load: %v", err)
}
if !cfg.MyService.Enabled {
t.Fatal("MyService.Enabled = false, want true (from env)")
}
}
func TestValidatorCalled(t *testing.T) {
toml := `
[server]
listen_addr = ":8443"
tls_cert = "/tmp/cert.pem"
tls_key = "/tmp/key.pem"
[database]
path = "/tmp/test.db"
[mcias]
server_url = "https://mcias.example.com"
`
path := writeTOML(t, toml)
// custom.required is missing → Validate should fail.
_, err := Load[validatingConfig](path, "TEST")
if err == nil {
t.Fatal("expected validation error for missing custom.required")
}
}
func TestValidatorPasses(t *testing.T) {
toml := `
[server]
listen_addr = ":8443"
tls_cert = "/tmp/cert.pem"
tls_key = "/tmp/key.pem"
[database]
path = "/tmp/test.db"
[mcias]
server_url = "https://mcias.example.com"
[custom]
required = "present"
`
path := writeTOML(t, toml)
cfg, err := Load[validatingConfig](path, "TEST")
if err != nil {
t.Fatalf("Load: %v", err)
}
if cfg.Custom.Required != "present" {
t.Fatalf("Custom.Required = %q, want %q", cfg.Custom.Required, "present")
}
}
func TestLoadNonexistentFile(t *testing.T) {
_, err := Load[testConfig]("/nonexistent/path.toml", "TEST")
if err == nil {
t.Fatal("expected error for nonexistent file")
}
}
func TestLoadInvalidTOML(t *testing.T) {
path := writeTOML(t, "this is not valid toml [[[")
_, err := Load[testConfig](path, "TEST")
if err == nil {
t.Fatal("expected error for invalid TOML")
}
}
func TestEmptyEnvPrefix(t *testing.T) {
path := writeTOML(t, minimalTOML)
// Should work fine with no env prefix (no overrides applied).
cfg, err := Load[testConfig](path, "")
if err != nil {
t.Fatalf("Load: %v", err)
}
if cfg.Server.ListenAddr != ":8443" {
t.Fatalf("ListenAddr = %q, want %q", cfg.Server.ListenAddr, ":8443")
}
}