minio/pkg/bucket/replication/rule.go

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/*
* 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 replication
import (
"bytes"
"encoding/xml"
)
// Status represents Enabled/Disabled status
type Status string
// Supported status types
const (
Enabled Status = "Enabled"
Disabled Status = "Disabled"
)
// DeleteMarkerReplication - whether delete markers are replicated - https://docs.aws.amazon.com/AmazonS3/latest/dev/replication-add-config.html
type DeleteMarkerReplication struct {
Status Status `xml:"Status"` // should be set to "Disabled" by default
}
// IsEmpty returns true if DeleteMarkerReplication is not set
func (d DeleteMarkerReplication) IsEmpty() bool {
return len(d.Status) == 0
}
// Validate validates whether the status is disabled.
func (d DeleteMarkerReplication) Validate() error {
if d.IsEmpty() {
return errDeleteMarkerReplicationMissing
}
if d.Status != Disabled && d.Status != Enabled {
return errInvalidDeleteMarkerReplicationStatus
}
return nil
}
// DeleteReplication - whether versioned deletes are replicated - this is a MinIO only
// extension.
type DeleteReplication struct {
Status Status `xml:"Status"` // should be set to "Disabled" by default
}
// IsEmpty returns true if DeleteReplication is not set
func (d DeleteReplication) IsEmpty() bool {
return len(d.Status) == 0
}
// Validate validates whether the status is disabled.
func (d DeleteReplication) Validate() error {
if d.IsEmpty() {
return errDeleteReplicationMissing
}
if d.Status != Disabled && d.Status != Enabled {
return errInvalidDeleteReplicationStatus
}
return nil
}
// UnmarshalXML - decodes XML data.
func (d *DeleteReplication) UnmarshalXML(dec *xml.Decoder, start xml.StartElement) (err error) {
// Make subtype to avoid recursive UnmarshalXML().
type deleteReplication DeleteReplication
drep := deleteReplication{}
if err := dec.DecodeElement(&drep, &start); err != nil {
return err
}
if len(drep.Status) == 0 {
drep.Status = Disabled
}
d.Status = drep.Status
return nil
}
// Rule - a rule for replication configuration.
type Rule struct {
XMLName xml.Name `xml:"Rule" json:"Rule"`
ID string `xml:"ID,omitempty" json:"ID,omitempty"`
Status Status `xml:"Status" json:"Status"`
Priority int `xml:"Priority" json:"Priority"`
DeleteMarkerReplication DeleteMarkerReplication `xml:"DeleteMarkerReplication" json:"DeleteMarkerReplication"`
// MinIO extension to replicate versioned deletes
DeleteReplication DeleteReplication `xml:"DeleteReplication" json:"DeleteReplication"`
Destination Destination `xml:"Destination" json:"Destination"`
Filter Filter `xml:"Filter" json:"Filter"`
}
var (
errInvalidRuleID = Errorf("ID must be less than 255 characters")
errEmptyRuleStatus = Errorf("Status should not be empty")
errInvalidRuleStatus = Errorf("Status must be set to either Enabled or Disabled")
errDeleteMarkerReplicationMissing = Errorf("DeleteMarkerReplication must be specified")
errPriorityMissing = Errorf("Priority must be specified")
errInvalidDeleteMarkerReplicationStatus = Errorf("Delete marker replication status is invalid")
errDestinationSourceIdentical = Errorf("Destination bucket cannot be the same as the source bucket.")
errDeleteReplicationMissing = Errorf("Delete replication must be specified")
errInvalidDeleteReplicationStatus = Errorf("Delete replication is either enable|disable")
)
// validateID - checks if ID is valid or not.
func (r Rule) validateID() error {
// cannot be longer than 255 characters
if len(r.ID) > 255 {
return errInvalidRuleID
}
return nil
}
// validateStatus - checks if status is valid or not.
func (r Rule) validateStatus() error {
// Status can't be empty
if len(r.Status) == 0 {
return errEmptyRuleStatus
}
// Status must be one of Enabled or Disabled
if r.Status != Enabled && r.Status != Disabled {
return errInvalidRuleStatus
}
return nil
}
func (r Rule) validateFilter() error {
if err := r.Filter.Validate(); err != nil {
return err
}
return nil
}
// Prefix - a rule can either have prefix under <filter></filter> or under
// <filter><and></and></filter>. This method returns the prefix from the
// location where it is available
func (r Rule) Prefix() string {
if r.Filter.Prefix != "" {
return r.Filter.Prefix
}
return r.Filter.And.Prefix
}
// Tags - a rule can either have tag under <filter></filter> or under
// <filter><and></and></filter>. This method returns all the tags from the
// rule in the format tag1=value1&tag2=value2
func (r Rule) Tags() string {
if !r.Filter.Tag.IsEmpty() {
return r.Filter.Tag.String()
}
if len(r.Filter.And.Tags) != 0 {
var buf bytes.Buffer
for _, t := range r.Filter.And.Tags {
if buf.Len() > 0 {
buf.WriteString("&")
}
buf.WriteString(t.String())
}
return buf.String()
}
return ""
}
// Validate - validates the rule element
func (r Rule) Validate(bucket string, sameTarget bool) error {
if err := r.validateID(); err != nil {
return err
}
if err := r.validateStatus(); err != nil {
return err
}
if err := r.validateFilter(); err != nil {
return err
}
if err := r.DeleteMarkerReplication.Validate(); err != nil {
return err
}
if err := r.DeleteReplication.Validate(); err != nil {
return err
}
if r.Priority < 0 {
return errPriorityMissing
}
if r.Destination.Bucket == bucket && sameTarget {
return errDestinationSourceIdentical
}
return nil
}