config: replace defaultConfig with a thread-safe in-memory implementation

fs/config/default_storage_test.go

@@ -0,0 +1,42 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDefaultStorage(t *testing.T) {
+	a := assert.New(t)
+
+	ds := newDefaultStorage()
+
+	section := "test"
+	key := "key"
+	val := "something"
+	ds.SetValue(section, key, val)
+	ds.SetValue("some other section", key, val)
+
+	v, hasVal := ds.GetValue(section, key)
+	a.True(hasVal)
+	a.Equal(val, v)
+
+	a.ElementsMatch([]string{section, "some other section"}, ds.GetSectionList())
+	a.True(ds.HasSection(section))
+	a.False(ds.HasSection("nope"))
+
+	a.Equal([]string{key}, ds.GetKeyList(section))
+
+	_, err := ds.Serialize()
+	a.NoError(err)
+
+	a.True(ds.DeleteKey(section, key))
+	a.False(ds.DeleteKey(section, key))
+	a.False(ds.DeleteKey("not there", key))
+
+	_, hasVal = ds.GetValue(section, key)
+	a.False(hasVal)
+
+	ds.DeleteSection(section)
+	a.False(ds.HasSection(section))
+}