config settings, overridable by settings.go or env (SCOPES_...) settings

config/config.go

@@ -1,6 +1,11 @@
 package config
 
-import "git.sr.ht/~cco/go-scopes/common"
+import (
+	"os"
+	"strings"
+
+	"git.sr.ht/~cco/go-scopes/common"
+)
 
 type Cfg struct {
 	*Base
@@ -51,3 +56,17 @@ func MakeBase(name string, starter common.StartFct) *Base {
 func Setup(cfg Config) Config {
 	return cfg
 }
+
+// overridable settings
+
+type Settings map[string]string
+
+func (s Settings) Get(key, def string) string {
+	if v, ok := os.LookupEnv("SCOPES_" + strings.ToUpper(key)); ok {
+		return v
+	}
+	if v, ok := s[key]; ok {
+		return v
+	}
+	return def
+}

examples/demo/etc/etc.go

@@ -6,9 +6,11 @@ import (
 )
 
 func Config() config.Config {
+	ovr := Overrides().Get
 	b := config.MakeBase
 	cfg := scopes.Cfg{
 		Base:    b("dummy", scopes.Start),
+		Home:    ovr(HOME, "."),
 		AppType: "standard",
 	}
 	cfg.Add(config.Cfg{b("config", config.Start), "etc"})
@@ -17,4 +19,5 @@ func Config() config.Config {
 
 const (
 	NAME = "name"
+	HOME = "home"
 )

examples/demo/etc/settings.go

@@ -1,7 +1,10 @@
 package etc
 
-func Override() map[string]string {
+import "git.sr.ht/~cco/go-scopes/config"
-	return map[string]string{
+
+func Overrides() config.Settings {
+	return config.Settings{
 		NAME: "overridden",
+		HOME: "/home/scopes/app",
 	}
 }

examples/demo/main.go

@@ -10,8 +10,9 @@ import (
 )
 
 func main() {
-	fmt.Println(etc.Override()["name"])
 	cfg := config.Setup(etc.Config())
 	fmt.Println(cfg.Name())
+	appCfg := cfg.(*scopes.Cfg)
+	fmt.Println(appCfg.Home)
 	scopes.RunApp(cfg)
 }

scopes.go

@@ -8,6 +8,7 @@ import (
 type Cfg struct {
 	*config.Base
 	AppType string
+	Home    string
 }
 
 func Start(ctx common.Context) {

tests/etc/etc.go

@@ -6,9 +6,11 @@ import (
 )
 
 func Config() config.Config {
+	ovr := Overrides().Get
 	b := config.MakeBase
 	cfg := scopes.Cfg{
 		Base:    b("dummy", scopes.Start),
+		Home:    ovr(HOME, "."),
 		AppType: "standard",
 	}
 	cfg.Add(config.Cfg{b("config", config.Start), "etc"})
@@ -19,12 +21,14 @@ func Config() config.Config {
 // explicit Override() or SCOPES_* environment settings.
 const (
 	NAME = "name"
+	HOME = "home"
 )
 
 // in a production scenario this should be put in separate
 // file `settings.go` that should not be stored in code repository.
-func Override() map[string]string {
+func Overrides() config.Settings {
-	return map[string]string{
+	return config.Settings{
 		NAME: "overridden",
+		HOME: "/home/scopes",
 	}
 }

tests/scopes_test.go

@@ -15,8 +15,10 @@ func TestConfig(tb *tbase.T) {
 }
 
 func ConfigTest(t *testing.T) {
-	t.AssertEqual(etc.Override()[etc.NAME], "overridden")
+	t.AssertEqual(etc.Overrides()[etc.NAME], "overridden")
 	cfg := config.Setup(etc.Config())
 	t.AssertEqual(cfg.Name(), "dummy")
+	appCfg := cfg.(*scopes.Cfg)
+	t.AssertEqual(appCfg.Home, "/home/scopes")
 	scopes.RunApp(cfg)
 }