From 81d19156e9cbe1750a20804302534fcfee557f8a Mon Sep 17 00:00:00 2001
From: Harshavardhana <harsha@minio.io>
Date: Thu, 18 Nov 2021 23:47:02 -0800
Subject: [PATCH] allow in-memory persistence for gateway (#13694)

NAS gateway would persist however with or without etcd as before.
---
 cmd/iam-dummy-store.go | 46 ++++++++++++++++++++++++++++++++++++++++++
 cmd/iam.go             |  8 +++++++-
 2 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/cmd/iam-dummy-store.go b/cmd/iam-dummy-store.go
index f4ebbd1fc..3a4b1c644 100644
--- a/cmd/iam-dummy-store.go
+++ b/cmd/iam-dummy-store.go
@@ -65,34 +65,80 @@ func (ids *iamDummyStore) migrateBackendFormat(context.Context) error {
 }
 
 func (ids *iamDummyStore) loadPolicyDoc(ctx context.Context, policy string, m map[string]iampolicy.Policy) error {
+	v, ok := ids.iamPolicyDocsMap[policy]
+	if !ok {
+		return errNoSuchPolicy
+	}
+	m[policy] = v
 	return nil
 }
 
 func (ids *iamDummyStore) loadPolicyDocs(ctx context.Context, m map[string]iampolicy.Policy) error {
+	for k, v := range ids.iamPolicyDocsMap {
+		m[k] = v
+	}
 	return nil
 }
 
 func (ids *iamDummyStore) loadUser(ctx context.Context, user string, userType IAMUserType, m map[string]auth.Credentials) error {
+	u, ok := ids.iamUsersMap[user]
+	if !ok {
+		return errNoSuchUser
+	}
+	ids.iamUsersMap[user] = u
 	return nil
 }
 
 func (ids *iamDummyStore) loadUsers(ctx context.Context, userType IAMUserType, m map[string]auth.Credentials) error {
+	for k, v := range ids.iamUsersMap {
+		m[k] = v
+	}
 	return nil
 }
 
 func (ids *iamDummyStore) loadGroup(ctx context.Context, group string, m map[string]GroupInfo) error {
+	g, ok := ids.iamGroupsMap[group]
+	if !ok {
+		return errNoSuchGroup
+	}
+	m[group] = g
 	return nil
 }
 
 func (ids *iamDummyStore) loadGroups(ctx context.Context, m map[string]GroupInfo) error {
+	for k, v := range ids.iamGroupsMap {
+		m[k] = v
+	}
 	return nil
 }
 
 func (ids *iamDummyStore) loadMappedPolicy(ctx context.Context, name string, userType IAMUserType, isGroup bool, m map[string]MappedPolicy) error {
+	if isGroup {
+		g, ok := ids.iamGroupPolicyMap[name]
+		if !ok {
+			return errNoSuchPolicy
+		}
+		m[name] = g
+	} else {
+		u, ok := ids.iamUserPolicyMap[name]
+		if !ok {
+			return errNoSuchPolicy
+		}
+		m[name] = u
+	}
 	return nil
 }
 
 func (ids *iamDummyStore) loadMappedPolicies(ctx context.Context, userType IAMUserType, isGroup bool, m map[string]MappedPolicy) error {
+	if !isGroup {
+		for k, v := range ids.iamUserPolicyMap {
+			m[k] = v
+		}
+	} else {
+		for k, v := range ids.iamGroupPolicyMap {
+			m[k] = v
+		}
+	}
 	return nil
 }
 
diff --git a/cmd/iam.go b/cmd/iam.go
index 72e2b3dff..b2a575db7 100644
--- a/cmd/iam.go
+++ b/cmd/iam.go
@@ -151,7 +151,13 @@ func (sys *IAMSys) initStore(objAPI ObjectLayer, etcdClient *etcd.Client) {
 
 	if etcdClient == nil {
 		if globalIsGateway {
-			sys.store = &IAMStoreSys{newIAMDummyStore(sys.usersSysType)}
+			if globalGatewayName == NASBackendGateway {
+				sys.store = &IAMStoreSys{newIAMObjectStore(objAPI, sys.usersSysType)}
+			} else {
+				sys.store = &IAMStoreSys{newIAMDummyStore(sys.usersSysType)}
+				logger.Info("WARNING: %s gateway is running in-memory IAM store, for persistence please configure etcd",
+					globalGatewayName)
+			}
 		} else {
 			sys.store = &IAMStoreSys{newIAMObjectStore(objAPI, sys.usersSysType)}
 		}