/*

* MinIO Cloud Storage, (C) 2020 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 cmd

import (

"context"

"crypto/sha256"

"encoding/hex"

"encoding/json"

"net/http"

"sync"

"sync/atomic"

"time"

minio "github.com/minio/minio-go/v7"

miniogo "github.com/minio/minio-go/v7"

"github.com/minio/minio-go/v7/pkg/credentials"

"github.com/minio/minio/cmd/crypto"

"github.com/minio/minio/pkg/bucket/versioning"

"github.com/minio/minio/pkg/madmin"

)

const (

defaultHealthCheckDuration = 100 * time.Second

)

// BucketTargetSys represents bucket targets subsystem

type BucketTargetSys struct {

sync.RWMutex

arnRemotesMap map[string]*TargetClient

targetsMap map[string][]madmin.BucketTarget

}

// ListTargets lists bucket targets across tenant or for individual bucket, and returns

// results filtered by arnType

func (sys *BucketTargetSys) ListTargets(ctx context.Context, bucket, arnType string) (targets []madmin.BucketTarget) {

if bucket != "" {

if ts, err := sys.ListBucketTargets(ctx, bucket); err == nil {

for _, t := range ts.Targets {

if string(t.Type) == arnType || arnType == "" {

targets = append(targets, t.Clone())

}

}

}

return targets

}

sys.RLock()

defer sys.RUnlock()

for _, tgts := range sys.targetsMap {

for _, t := range tgts {

if string(t.Type) == arnType || arnType == "" {

targets = append(targets, t.Clone())

}

}

}

return

}

// ListBucketTargets - gets list of bucket targets for this bucket.

func (sys *BucketTargetSys) ListBucketTargets(ctx context.Context, bucket string) (*madmin.BucketTargets, error) {

sys.RLock()

defer sys.RUnlock()

tgts, ok := sys.targetsMap[bucket]

if ok {

return &madmin.BucketTargets{Targets: tgts}, nil

}

return nil, BucketRemoteTargetNotFound{Bucket: bucket}

}

// SetTarget - sets a new minio-go client target for this bucket.

func (sys *BucketTargetSys) SetTarget(ctx context.Context, bucket string, tgt *madmin.BucketTarget, update bool) error {

if globalIsGateway {

return nil

}

if !tgt.Type.IsValid() && !update {

return BucketRemoteArnTypeInvalid{Bucket: bucket}

}

clnt, err := sys.getRemoteTargetClient(tgt)

if err != nil {

return BucketRemoteTargetNotFound{Bucket: tgt.TargetBucket}

}

// validate if target credentials are ok

if _, err = clnt.BucketExists(ctx, tgt.TargetBucket); err != nil {

if minio.ToErrorResponse(err).Code == "NoSuchBucket" {

return BucketRemoteTargetNotFound{Bucket: tgt.TargetBucket}

}

return BucketRemoteConnectionErr{Bucket: tgt.TargetBucket}

}

if tgt.Type == madmin.ReplicationService {

if !globalIsErasure {

return NotImplemented{}

}

if !globalBucketVersioningSys.Enabled(bucket) {

return BucketReplicationSourceNotVersioned{Bucket: bucket}

}

vcfg, err := clnt.GetBucketVersioning(ctx, tgt.TargetBucket)

if err != nil {

return BucketRemoteConnectionErr{Bucket: tgt.TargetBucket}

}

if vcfg.Status != string(versioning.Enabled) {

return BucketRemoteTargetNotVersioned{Bucket: tgt.TargetBucket}

}

}

sys.Lock()

defer sys.Unlock()

tgts := sys.targetsMap[bucket]

newtgts := make([]madmin.BucketTarget, len(tgts))

found := false

for idx, t := range tgts {

if t.Type == tgt.Type {

if t.Arn == tgt.Arn && !update {

return BucketRemoteAlreadyExists{Bucket: t.TargetBucket}

}

newtgts[idx] = *tgt

found = true

continue

}

newtgts[idx] = t

}

if !found && !update {

newtgts = append(newtgts, *tgt)

}

sys.targetsMap[bucket] = newtgts

sys.arnRemotesMap[tgt.Arn] = clnt

return nil

}

// RemoveTarget - removes a remote bucket target for this source bucket.

func (sys *BucketTargetSys) RemoveTarget(ctx context.Context, bucket, arnStr string) error {

if globalIsGateway {

return nil

}

if arnStr == "" {

return BucketRemoteArnInvalid{Bucket: bucket}

}

arn, err := madmin.ParseARN(arnStr)

if err != nil {

return BucketRemoteArnInvalid{Bucket: bucket}

}

if arn.Type == madmin.ReplicationService {

if !globalIsErasure {

return NotImplemented{}

}

// reject removal of remote target if replication configuration is present

rcfg, err := getReplicationConfig(ctx, bucket)

if err == nil && rcfg.RoleArn == arnStr {

if _, ok := sys.arnRemotesMap[arnStr]; ok {

return BucketRemoteRemoveDisallowed{Bucket: bucket}

}

}

}

// delete ARN type from list of matching targets

sys.Lock()

defer sys.Unlock()

found := false

tgts, ok := sys.targetsMap[bucket]

if !ok {

return BucketRemoteTargetNotFound{Bucket: bucket}

}

targets := make([]madmin.BucketTarget, 0, len(tgts))

for _, tgt := range tgts {

if tgt.Arn != arnStr {

targets = append(targets, tgt)

continue

}

found = true

}

if !found {

return BucketRemoteTargetNotFound{Bucket: bucket}

}

sys.targetsMap[bucket] = targets

delete(sys.arnRemotesMap, arnStr)

return nil

}

// GetRemoteTargetClient returns minio-go client for replication target instance

func (sys *BucketTargetSys) GetRemoteTargetClient(ctx context.Context, arn string) *TargetClient {

sys.RLock()

defer sys.RUnlock()

return sys.arnRemotesMap[arn]

}

// NewBucketTargetSys - creates new replication system.

func NewBucketTargetSys() *BucketTargetSys {

return &BucketTargetSys{

arnRemotesMap: make(map[string]*TargetClient),

targetsMap: make(map[string][]madmin.BucketTarget),

}

}

// Init initializes the bucket targets subsystem for buckets which have targets configured.

func (sys *BucketTargetSys) Init(ctx context.Context, buckets []BucketInfo, objAPI ObjectLayer) error {

if objAPI == nil {

return errServerNotInitialized

}

// In gateway mode, bucket targets is not supported.

if globalIsGateway {

return nil

}

// Load bucket targets once during boot in background.

go sys.load(ctx, buckets, objAPI)

return nil

}

// UpdateAllTargets updates target to reflect metadata updates

func (sys *BucketTargetSys) UpdateAllTargets(bucket string, tgts *madmin.BucketTargets) {

if sys == nil {

return

}

sys.Lock()

defer sys.Unlock()

if tgts == nil || tgts.Empty() {

// remove target and arn association

if tgts, ok := sys.targetsMap[bucket]; ok {

for _, t := range tgts {

delete(sys.arnRemotesMap, t.Arn)

}

}

delete(sys.targetsMap, bucket)

return

}

if len(tgts.Targets) > 0 {

sys.targetsMap[bucket] = tgts.Targets

}

for _, tgt := range tgts.Targets {

tgtClient, err := sys.getRemoteTargetClient(&tgt)

if err != nil {

continue

}

sys.arnRemotesMap[tgt.Arn] = tgtClient

}

sys.targetsMap[bucket] = tgts.Targets

}

// create minio-go clients for buckets having remote targets

func (sys *BucketTargetSys) load(ctx context.Context, buckets []BucketInfo, objAPI ObjectLayer) {

for _, bucket := range buckets {

cfg, err := globalBucketMetadataSys.GetBucketTargetsConfig(bucket.Name)

if err != nil {

continue

}

if cfg == nil || cfg.Empty() {

continue

}

if len(cfg.Targets) > 0 {

sys.targetsMap[bucket.Name] = cfg.Targets

}

for _, tgt := range cfg.Targets {

tgtClient, err := sys.getRemoteTargetClient(&tgt)

if err != nil {

continue

}

sys.arnRemotesMap[tgt.Arn] = tgtClient

}

sys.targetsMap[bucket.Name] = cfg.Targets

}

}

// getRemoteTargetInstanceTransport contains a singleton roundtripper.

var getRemoteTargetInstanceTransport http.RoundTripper

var getRemoteTargetInstanceTransportOnce sync.Once

// Returns a minio-go Client configured to access remote host described in replication target config.

func (sys *BucketTargetSys) getRemoteTargetClient(tcfg *madmin.BucketTarget) (*TargetClient, error) {

config := tcfg.Credentials

creds := credentials.NewStaticV4(config.AccessKey, config.SecretKey, "")

getRemoteTargetInstanceTransportOnce.Do(func() {

getRemoteTargetInstanceTransport = newGatewayHTTPTransport(10 * time.Minute)

})

api, err := minio.New(tcfg.Endpoint, &miniogo.Options{

Creds: creds,

Secure: tcfg.Secure,

Region: tcfg.Region,

Transport: getRemoteTargetInstanceTransport,

})

if err != nil {

return nil, err

}

hcDuration := defaultHealthCheckDuration

if tcfg.HealthCheckDuration >= 1 { // require minimum health check duration of 1 sec.

hcDuration = tcfg.HealthCheckDuration

}

tc := &TargetClient{

Client: api,

healthCheckDuration: hcDuration,

replicateSync: tcfg.ReplicationSync,

Bucket: tcfg.TargetBucket,

StorageClass: tcfg.StorageClass,

}

go tc.healthCheck()

return tc, nil

}

// getRemoteARN gets existing ARN for an endpoint or generates a new one.

func (sys *BucketTargetSys) getRemoteARN(bucket string, target *madmin.BucketTarget) string {

if target == nil {

return ""

}

tgts := sys.targetsMap[bucket]

for _, tgt := range tgts {

if tgt.Type == target.Type && tgt.TargetBucket == target.TargetBucket && target.URL().String() == tgt.URL().String() {

return tgt.Arn

}

}

if !madmin.ServiceType(target.Type).IsValid() {

return ""

}

return generateARN(target)

}

// generate ARN that is unique to this target type

func generateARN(t *madmin.BucketTarget) string {

hash := sha256.New()

hash.Write([]byte(t.Type))

hash.Write([]byte(t.Region))

hash.Write([]byte(t.TargetBucket))

hashSum := hex.EncodeToString(hash.Sum(nil))

arn := madmin.ARN{

Type: t.Type,

ID: hashSum,

Region: t.Region,

Bucket: t.TargetBucket,

}

return arn.String()

}

// Returns parsed target config. If KMS is configured, remote target is decrypted

func parseBucketTargetConfig(bucket string, cdata, cmetadata []byte) (*madmin.BucketTargets, error) {

var (

data []byte

err error

t madmin.BucketTargets

meta map[string]string

)

if len(cdata) == 0 {

return nil, nil

}

data = cdata

if len(cmetadata) != 0 {

if err := json.Unmarshal(cmetadata, &meta); err != nil {

return nil, err

}

if crypto.S3.IsEncrypted(meta) {

if data, err = decryptBucketMetadata(cdata, bucket, meta, crypto.Context{bucket: bucket, bucketTargetsFile: bucketTargetsFile}); err != nil {

return nil, err

}

}

}

if err = json.Unmarshal(data, &t); err != nil {

return nil, err

}

return &t, nil

}

// TargetClient is the struct for remote target client.

type TargetClient struct {

*miniogo.Client

up int32

healthCheckDuration time.Duration

Bucket string // remote bucket target

replicateSync bool

StorageClass string // storage class on remote

}

func (tc *TargetClient) isOffline() bool {

return atomic.LoadInt32(&tc.up) == 0

}

func (tc *TargetClient) healthCheck() {

for {

_, err := tc.BucketExists(GlobalContext, tc.Bucket)

if err != nil {

atomic.StoreInt32(&tc.up, 0)

time.Sleep(tc.healthCheckDuration)

continue

}

atomic.StoreInt32(&tc.up, 1)

time.Sleep(tc.healthCheckDuration)

}

}