v0.0.55

confext/confParser.go

@@ -14,9 +14,21 @@ import (
 // ApplyEnvOverrides overrides field values from environment variables
 //
 // fields must be tagged with `env:"env_key"`
-func ApplyEnvOverrides[T any](c *T) error {
+//
-
+// only works on exported fields
+//
+// fields without an env tag are ignored
+// fields with an `env:"-"` tag are ignore
+//
+// sub-structs are recursively parsed (if they have an env tag) and the env-variable keys are delimited by the delim parameter
+// sub-structs with `env:""` are also parsed, but the delimited is skipped (they are handled as if they were one level higher)
+func ApplyEnvOverrides[T any](c *T, delim string) error {
 	rval := reflect.ValueOf(c).Elem()
+
+	return processEnvOverrides(rval, delim, "")
+}
+
+func processEnvOverrides(rval reflect.Value, delim string, prefix string) error {
 	rtyp := rval.Type()
 
 	for i := 0; i < rtyp.NumField(); i++ {
@@ -24,12 +36,36 @@ func ApplyEnvOverrides[T any](c *T) error {
 		rsfield := rtyp.Field(i)
 		rvfield := rval.Field(i)
 
-		envkey := rsfield.Tag.Get("env")
+		if !rsfield.IsExported() {
-		if envkey == "" {
 			continue
 		}
 
-		envval, efound := os.LookupEnv(envkey)
+		if rvfield.Kind() == reflect.Struct {
+
+			envkey, found := rsfield.Tag.Lookup("env")
+			if !found || envkey == "-" {
+				continue
+			}
+
+			subPrefix := prefix
+			if envkey != "" {
+				subPrefix = subPrefix + envkey + delim
+			}
+
+			err := processEnvOverrides(rvfield, delim, subPrefix)
+			if err != nil {
+				return err
+			}
+		}
+
+		envkey := rsfield.Tag.Get("env")
+		if envkey == "" || envkey == "-" {
+			continue
+		}
+
+		fullEnvKey := prefix + envkey
+
+		envval, efound := os.LookupEnv(fullEnvKey)
 		if !efound {
 			continue
 		}
@@ -38,86 +74,86 @@ func ApplyEnvOverrides[T any](c *T) error {
 
 			rvfield.Set(reflect.ValueOf(envval))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, envval)
+			fmt.Printf("[CONF] Overwrite config '%s' () with '%s'\n", fullEnvKey, envval)
 
 		} else if rvfield.Type() == reflect.TypeOf(int(0)) {
 
 			envint, err := strconv.ParseInt(envval, 10, bits.UintSize)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int (value := '%s')", envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int (value := '%s')", fullEnvKey, envval))
 			}
 
 			rvfield.Set(reflect.ValueOf(int(envint)))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, envval)
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, envval)
 
 		} else if rvfield.Type() == reflect.TypeOf(int64(0)) {
 
 			envint, err := strconv.ParseInt(envval, 10, 64)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int64 (value := '%s')", envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int64 (value := '%s')", fullEnvKey, envval))
 			}
 
 			rvfield.Set(reflect.ValueOf(int64(envint)))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, envval)
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, envval)
 
 		} else if rvfield.Type() == reflect.TypeOf(int32(0)) {
 
 			envint, err := strconv.ParseInt(envval, 10, 32)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int32 (value := '%s')", envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int32 (value := '%s')", fullEnvKey, envval))
 			}
 
 			rvfield.Set(reflect.ValueOf(int32(envint)))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, envval)
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, envval)
 
 		} else if rvfield.Type() == reflect.TypeOf(int8(0)) {
 
 			envint, err := strconv.ParseInt(envval, 10, 8)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int32 (value := '%s')", envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int32 (value := '%s')", fullEnvKey, envval))
 			}
 
 			rvfield.Set(reflect.ValueOf(int8(envint)))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, envval)
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, envval)
 
 		} else if rvfield.Type() == reflect.TypeOf(time.Duration(0)) {
 
 			dur, err := timeext.ParseDurationShortString(envval)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to duration (value := '%s')", envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to duration (value := '%s')", fullEnvKey, envval))
 			}
 
 			rvfield.Set(reflect.ValueOf(dur))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, dur.String())
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, dur.String())
 
 		} else if rvfield.Type() == reflect.TypeOf(time.UnixMilli(0)) {
 
 			tim, err := time.Parse(time.RFC3339Nano, envval)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to time.time (value := '%s')", envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to time.time (value := '%s')", fullEnvKey, envval))
 			}
 
 			rvfield.Set(reflect.ValueOf(tim))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, tim.String())
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, tim.String())
 
 		} else if rvfield.Type().ConvertibleTo(reflect.TypeOf(int(0))) {
 
 			envint, err := strconv.ParseInt(envval, 10, 8)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to <%s, ,int> (value := '%s')", rvfield.Type().Name(), envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to <%s, ,int> (value := '%s')", rvfield.Type().Name(), fullEnvKey, envval))
 			}
 
 			envcvl := reflect.ValueOf(envint).Convert(rvfield.Type())
 
 			rvfield.Set(envcvl)
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%v'\n", envkey, envcvl.Interface())
+			fmt.Printf("[CONF] Overwrite config '%s' with '%v'\n", fullEnvKey, envcvl.Interface())
 
 		} else if rvfield.Type().ConvertibleTo(reflect.TypeOf("")) {
 
@@ -125,7 +161,7 @@ func ApplyEnvOverrides[T any](c *T) error {
 
 			rvfield.Set(envcvl)
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%v'\n", envkey, envcvl.Interface())
+			fmt.Printf("[CONF] Overwrite config '%s' with '%v'\n", fullEnvKey, envcvl.Interface())
 
 		} else {
 			return errors.New(fmt.Sprintf("Unknown kind/type in config: [ %s | %s ]", rvfield.Kind().String(), rvfield.Type().String()))

confext/confParser_test.go

@@ -1,6 +1,7 @@
 package confext
 
 import (
+	"gogs.mikescher.com/BlackForestBytes/goext/timeext"
 	"testing"
 	"time"
 )
@@ -40,7 +41,7 @@ func TestApplyEnvOverridesNoop(t *testing.T) {
 
 	output := input
 
-	err := ApplyEnvOverrides(&output)
+	err := ApplyEnvOverrides(&output, ".")
 	if err != nil {
 		t.Errorf("%v", err)
 		t.FailNow()
@@ -92,7 +93,7 @@ func TestApplyEnvOverridesSimple(t *testing.T) {
 	t.Setenv("TEST_V8", "1min4s")
 	t.Setenv("TEST_V9", "2009-11-10T23:00:00Z")
 
-	err := ApplyEnvOverrides(&data)
+	err := ApplyEnvOverrides(&data, ".")
 	if err != nil {
 		t.Errorf("%v", err)
 		t.FailNow()
@@ -109,6 +110,109 @@ func TestApplyEnvOverridesSimple(t *testing.T) {
 	assertEqual(t, data.V9, time.Unix(1257894000, 0).UTC())
 }
 
+func TestApplyEnvOverridesRecursive(t *testing.T) {
+
+	type subdata struct {
+		V1 int           `env:"SUB_V1"`
+		VX string        ``
+		V2 string        `env:"SUB_V2"`
+		V8 time.Duration `env:"SUB_V3"`
+		V9 time.Time     `env:"SUB_V4"`
+	}
+
+	type testdata struct {
+		V1   int     `env:"TEST_V1"`
+		VX   string  ``
+		Sub1 subdata ``
+		Sub2 subdata `env:"TEST_V2"`
+		Sub3 subdata `env:"TEST_V3"`
+		Sub4 subdata `env:""`
+		V5   string  `env:"-"`
+	}
+
+	data := testdata{
+		V1: 1,
+		VX: "2",
+		V5: "no",
+		Sub1: subdata{
+			V1: 3,
+			VX: "4",
+			V2: "5",
+			V8: 6 * time.Second,
+			V9: time.Date(2000, 1, 7, 1, 1, 1, 0, time.UTC),
+		},
+		Sub2: subdata{
+			V1: 8,
+			VX: "9",
+			V2: "10",
+			V8: 11 * time.Second,
+			V9: time.Date(2000, 1, 12, 1, 1, 1, 0, timeext.TimezoneBerlin),
+		},
+		Sub3: subdata{
+			V1: 13,
+			VX: "14",
+			V2: "15",
+			V8: 16 * time.Second,
+			V9: time.Date(2000, 1, 17, 1, 1, 1, 0, timeext.TimezoneBerlin),
+		},
+		Sub4: subdata{
+			V1: 18,
+			VX: "19",
+			V2: "20",
+			V8: 21 * time.Second,
+			V9: time.Date(2000, 1, 22, 1, 1, 1, 0, timeext.TimezoneBerlin),
+		},
+	}
+
+	t.Setenv("TEST_V1", "999")
+	t.Setenv("-", "yes")
+
+	t.Setenv("TEST_V2_SUB_V1", "846")
+	t.Setenv("TEST_V2_SUB_V2", "222_hello_world")
+	t.Setenv("TEST_V2_SUB_V3", "1min4s")
+	t.Setenv("TEST_V2_SUB_V4", "2009-11-10T23:00:00Z")
+
+	t.Setenv("TEST_V3_SUB_V1", "33846")
+	t.Setenv("TEST_V3_SUB_V2", "33_hello_world")
+	t.Setenv("TEST_V3_SUB_V3", "33min4s")
+	t.Setenv("TEST_V3_SUB_V4", "2033-11-10T23:00:00Z")
+
+	t.Setenv("SUB_V1", "11")
+	t.Setenv("SUB_V2", "22")
+	t.Setenv("SUB_V3", "33min")
+	t.Setenv("SUB_V4", "2044-01-01T00:00:00Z")
+
+	err := ApplyEnvOverrides(&data, "_")
+	if err != nil {
+		t.Errorf("%v", err)
+		t.FailNow()
+	}
+
+	assertEqual(t, data.V1, 999)
+	assertEqual(t, data.VX, "2")
+	assertEqual(t, data.V5, "no")
+	assertEqual(t, data.Sub1.V1, 3)
+	assertEqual(t, data.Sub1.VX, "4")
+	assertEqual(t, data.Sub1.V2, "5")
+	assertEqual(t, data.Sub1.V8, time.Second*6)
+	assertEqual(t, data.Sub1.V9, time.Unix(947206861, 0).UTC())
+	assertEqual(t, data.Sub2.V1, 846)
+	assertEqual(t, data.Sub2.VX, "9")
+	assertEqual(t, data.Sub2.V2, "222_hello_world")
+	assertEqual(t, data.Sub2.V8, time.Second*64)
+	assertEqual(t, data.Sub2.V9, time.Unix(1257894000, 0).UTC())
+	assertEqual(t, data.Sub3.V1, 33846)
+	assertEqual(t, data.Sub3.VX, "14")
+	assertEqual(t, data.Sub3.V2, "33_hello_world")
+	assertEqual(t, data.Sub3.V8, time.Second*1984)
+	assertEqual(t, data.Sub3.V9, time.Unix(2015276400, 0).UTC())
+	assertEqual(t, data.Sub4.V1, 11)
+	assertEqual(t, data.Sub4.VX, "19")
+	assertEqual(t, data.Sub4.V2, "22")
+	assertEqual(t, data.Sub4.V8, time.Second*1980)
+	assertEqual(t, data.Sub4.V9, time.Unix(2335219200, 0).UTC())
+}
+
 func assertEqual[T comparable](t *testing.T, actual T, expected T) {
 	if actual != expected {
 		t.Errorf("values differ: Actual: '%v', Expected: '%v'", actual, expected)