Re-order configuration precedence

changelog.md

@@ -18,6 +18,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - support JSON logging and make it the default
 - support log level configuration
 - update dependencies
+- re-order configuration precedence
+  1. default config file idp.toml
+  2. config files given via the `--conf` command line argument
+  3. environment variables with the `IDP_` prefix
 ### Fixed
 - run deb-systemd-helper in Debian package `postinst` script
 

internal/services/configuration.go

@@ -32,7 +32,10 @@ import (
 	"github.com/spf13/pflag"
 )
 
-const defaultServerPort = 3000
+const (
+	defaultServerPort = 3000
+	defaultFile       = "idp.toml"
+)
 
 var DefaultConfig = map[string]interface{}{
 	"server.bind_address":     "",
@@ -74,6 +77,10 @@ func ConfigureApplication(
 
 	_ = config.Load(confmap.Provider(defaultConfig, "."), nil)
 
+	if err = config.Load(file.Provider(defaultFile), toml.Parser()); err != nil && !os.IsNotExist(err) {
+		logrus.WithError(err).WithField("file", defaultFile).Fatal("error loading configuration from file")
+	}
+
 	cFiles, _ := f.GetStringSlice("conf")
 	for _, c := range cFiles {
 		if err = config.Load(file.Provider(c), toml.Parser()); err != nil {
@@ -85,13 +92,6 @@ func ConfigureApplication(
 		logger.WithError(err).Fatal("error loading configuration from command line")
 	}
 
-	if err = config.Load(
-		file.Provider("idp.toml"),
-		toml.Parser(),
-	); err != nil && !os.IsNotExist(err) {
-		logrus.WithError(err).Fatal("error loading configuration from resource_app.toml")
-	}
-
 	prefix := fmt.Sprintf("%s_", strings.ToUpper(appName))
 
 	if err = config.Load(env.Provider(prefix, ".", func(s string) string {