Migrate config to KV data format (#8392)

- adding oauth support to MinIO browser (#8400) by @kanagaraj
- supports multi-line get/set/del for all config fields
- add support for comments, allow toggle
- add extensive validation of config before saving
- support MinIO browser to support proper claims, using STS tokens
- env support for all config parameters, legacy envs are also
  supported with all documentation now pointing to latest ENVs
- preserve accessKey/secretKey from FS mode setups
- add history support implements three APIs
  - ClearHistory
  - RestoreHistory
  - ListHistory
- add help command support for each config parameters
- all the bug fixes after migration to KV, and other bug
  fixes encountered during testing.

cmd/config/identity/ldap/config_test.go

@@ -0,0 +1,87 @@
+/*
+ * MinIO Cloud Storage, (C) 2019 MinIO, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ldap
+
+import (
+	"testing"
+)
+
+func TestSubstituter(t *testing.T) {
+	tests := []struct {
+		KV               []string
+		SubstitutableStr string
+		SubstitutedStr   string
+		ErrExpected      bool
+	}{
+		{
+			KV:               []string{"username", "john"},
+			SubstitutableStr: "uid=${username},cn=users,dc=example,dc=com",
+			SubstitutedStr:   "uid=john,cn=users,dc=example,dc=com",
+			ErrExpected:      false,
+		},
+		{
+			KV:               []string{"username", "john"},
+			SubstitutableStr: "uid={username},cn=users,dc=example,dc=com",
+			SubstitutedStr:   "uid=john,cn=users,dc=example,dc=com",
+			ErrExpected:      false,
+		},
+		{
+			KV:               []string{"username", "john"},
+			SubstitutableStr: "(&(objectclass=group)(member=${username}))",
+			SubstitutedStr:   "(&(objectclass=group)(member=john))",
+			ErrExpected:      false,
+		},
+		{
+			KV:               []string{"username", "john"},
+			SubstitutableStr: "(&(objectclass=group)(member={username}))",
+			SubstitutedStr:   "(&(objectclass=group)(member=john))",
+			ErrExpected:      false,
+		},
+		{
+			KV:               []string{"username", "john"},
+			SubstitutableStr: "uid=${{username}},cn=users,dc=example,dc=com",
+			ErrExpected:      true,
+		},
+		{
+			KV:               []string{"username", "john"},
+			SubstitutableStr: "uid=${usernamedn},cn=users,dc=example,dc=com",
+			ErrExpected:      true,
+		},
+		{
+			KV:               []string{"username"},
+			SubstitutableStr: "uid=${usernamedn},cn=users,dc=example,dc=com",
+			ErrExpected:      true,
+		},
+	}
+
+	for _, test := range tests {
+		test := test
+		t.Run(test.SubstitutableStr, func(t *testing.T) {
+			subber, err := NewSubstituter(test.KV...)
+			if err != nil && !test.ErrExpected {
+				t.Errorf("Unexpected failure %s", err)
+			}
+			gotStr, err := subber.Substitute(test.SubstitutableStr)
+			if err != nil && !test.ErrExpected {
+				t.Errorf("Unexpected failure %s", err)
+			}
+			if gotStr != test.SubstitutedStr {
+				t.Errorf("Expected %s, got %s", test.SubstitutedStr, gotStr)
+			}
+		})
+	}
+}