Add KV store providers (dynamic configuration only)

Co-authored-by: Jean-Baptiste Doumenjou <jb.doumenjou@gmail.com>

pkg/config/kv/kv_test.go

@@ -0,0 +1,63 @@
+package kv
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDecode(t *testing.T) {
+	pairs := mapToPairs(map[string]string{
+		"traefik/fielda":        "bar",
+		"traefik/fieldb":        "1",
+		"traefik/fieldc":        "true",
+		"traefik/fieldd/0":      "one",
+		"traefik/fieldd/1":      "two",
+		"traefik/fielde":        "",
+		"traefik/fieldf/Test1":  "A",
+		"traefik/fieldf/Test2":  "B",
+		"traefik/fieldg/0/name": "A",
+		"traefik/fieldg/1/name": "B",
+	})
+
+	element := &sample{}
+
+	err := Decode(pairs, element, "traefik")
+	require.NoError(t, err)
+
+	expected := &sample{
+		FieldA: "bar",
+		FieldB: 1,
+		FieldC: true,
+		FieldD: []string{"one", "two"},
+		FieldE: &struct {
+			Name string
+		}{},
+		FieldF: map[string]string{
+			"Test1": "A",
+			"Test2": "B",
+		},
+		FieldG: []sub{
+			{Name: "A"},
+			{Name: "B"},
+		},
+	}
+	assert.Equal(t, expected, element)
+}
+
+type sample struct {
+	FieldA string
+	FieldB int
+	FieldC bool
+	FieldD []string
+	FieldE *struct {
+		Name string
+	} `label:"allowEmpty"`
+	FieldF map[string]string
+	FieldG []sub
+}
+
+type sub struct {
+	Name string
+}