config: Handle errors better

internal/config/config_template

@@ -69,6 +69,10 @@ GRAPHDB_ADMIN_PASSWORD=${GRAPHDB_ADMIN_PASSWORD}
 MYSQL_ADMIN_USER=${MYSQL_ADMIN_USER}
 MYSQL_ADMIN_PASSWORD=${MYSQL_ADMIN_PASSWORD}
 
+# The admin user and password required to access the keycloak server and api
+KEYCLOAK_ADMIN_USER=${KEYCLOAK_ADMIN_USER}
+KEYCLOAK_ADMIN_PASSWORD=${KEYCLOAK_ADMIN_PASSWORD}
+
 # The admin user and password required to access the /dis/ server and api
 DIS_ADMIN_USER=${DIS_ADMIN_USER}
 DIS_ADMIN_PASSWORD=${DIS_ADMIN_PASSWORD}

internal/config/read.go

@@ -7,6 +7,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
 	"github.com/FAU-CDI/wisski-distillery/pkg/envreader"
 	"github.com/FAU-CDI/wisski-distillery/pkg/stringparser"
+	"github.com/pkg/errors"
 )
 
 // Unmarshal updates this configuration from the provided [io.Reader].
@@ -45,15 +46,14 @@ func (config *Config) Unmarshal(env environment.Environment, src io.Reader) erro
 		// read the value with a default
 		value, ok := values[tEnv]
 		if !ok || value == "" {
-			if tDefault == "" {
+			if tDefault != "" {
-				continue
+				value = tDefault
 			}
-			value = tDefault
 		}
 
 		// parse the value!
 		if err := stringparser.Parse(env, tParser, value, vField); err != nil {
-			return err
+			return errors.Errorf("Config.Unmarshal: Setting %q, Parser %q: %s", tEnv, tParser, err)
 		}
 	}
 

internal/dis/component/component.go

@@ -20,6 +20,10 @@ type Component interface {
 	// Name should be implemented by the [ComponentBase] struct.
 	Name() string
 
+	// ID returns a unique id of this component
+	// ID should be implemented by the [ComponentBase] struct.
+	ID() string
+
 	// getBase returns the underlying ComponentBase object of this Component.
 	// It is used internally during initialization
 	getBase() *Base
@@ -27,8 +31,8 @@ type Component interface {
 
 // Base is embedded into every Component
 type Base struct {
-	name  string // name is the name of this component
+	name, id string // name and id of this component
-	Still        // the underlying still of the distillery
+	Still           // the underlying still of the distillery
 }
 
 //lint:ignore U1000 used to implement the private methods of [Component]
@@ -41,7 +45,11 @@ func (cb *Base) getBase() *Base {
 func Init(component Component, core Still) Component {
 	base := component.getBase() // pointer to a struct
 	base.Still = core
-	base.name = strings.ToLower(reflect.TypeOf(component).Elem().Name())
+
+	tp := reflect.TypeOf(component).Elem()
+	base.name = strings.ToLower(tp.Name())
+	base.id = tp.PkgPath() + "." + tp.Name()
+
 	return component
 }
 
@@ -49,6 +57,10 @@ func (cb Base) Name() string {
 	return cb.name
 }
 
+func (cb Base) ID() string {
+	return cb.id
+}
+
 // Still represents the central part of a distillery.
 // It is used inside the main distillery struct, as well as every component via [ComponentBase].
 type Still struct {

pkg/stringparser/parse.go

@@ -8,19 +8,21 @@ import (
 	"github.com/pkg/errors"
 )
 
+var errUnknownParser = errors.New("unknown parser")
+
 // Parse parses the provided value with the parser.
 func Parse(env environment.Environment, name, value string, vField reflect.Value) error {
 
 	// use the validator
 	parser, ok := knownParsers[strings.ToLower(name)]
 	if parser == nil || !ok {
-		return errors.Errorf("unknown parser %q", name)
+		return errUnknownParser
 	}
 
 	// get the parsed value
 	checked, err := parser(env, value)
 	if err != nil {
-		return errors.Wrapf(err, "parser %s returned error", name)
+		return err
 	}
 
 	// set the value of the field
@@ -34,7 +36,7 @@ func Parse(env environment.Environment, name, value string, vField reflect.Value
 
 	// capture any error
 	if errSet != nil {
-		return errors.Errorf("parser %s: set returned %v", name, errSet)
+		return errors.Errorf("set returned %v", name, errSet)
 	}
 
 	return nil