syncthing/vendor/github.com/minio/minio-go/post-policy.go
Jakob Borg 916ec63af6 cmd/stdiscosrv: New discovery server (fixes #4618)
This is a new revision of the discovery server. Relevant changes and
non-changes:

- Protocol towards clients is unchanged.

- Recommended large scale design is still to be deployed nehind nginx (I
  tested, and it's still a lot faster at terminating TLS).

- Database backend is leveldb again, only. It scales enough, is easy to
  setup, and we don't need any backend to take care of.

- Server supports replication. This is a simple TCP channel - protect it
  with a firewall when deploying over the internet. (We deploy this within
  the same datacenter, and with firewall.) Any incoming client announces
  are sent over the replication channel(s) to other peer discosrvs.
  Incoming replication changes are applied to the database as if they came
  from clients, but without the TLS/certificate overhead.

- Metrics are exposed using the prometheus library, when enabled.

- The database values and replication protocol is protobuf, because JSON
  was quite CPU intensive when I tried that and benchmarked it.

- The "Retry-After" value for failed lookups gets slowly increased from
  a default of 120 seconds, by 5 seconds for each failed lookup,
  independently by each discosrv. This lowers the query load over time for
  clients that are never seen. The Retry-After maxes out at 3600 after a
  couple of weeks of this increase. The number of failed lookups is
  stored in the database, now and then (avoiding making each lookup a
  database put).

All in all this means clients can be pointed towards a cluster using
just multiple A / AAAA records to gain both load sharing and redundancy
(if one is down, clients will talk to the remaining ones).

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4648
2018-01-14 08:52:31 +00:00

249 lines
7.0 KiB
Go

/*
* Minio Go Library for Amazon S3 Compatible Cloud Storage
* Copyright 2015-2017 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 minio
import (
"encoding/base64"
"fmt"
"strings"
"time"
)
// expirationDateFormat date format for expiration key in json policy.
const expirationDateFormat = "2006-01-02T15:04:05.999Z"
// policyCondition explanation:
// http://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-HTTPPOSTConstructPolicy.html
//
// Example:
//
// policyCondition {
// matchType: "$eq",
// key: "$Content-Type",
// value: "image/png",
// }
//
type policyCondition struct {
matchType string
condition string
value string
}
// PostPolicy - Provides strict static type conversion and validation
// for Amazon S3's POST policy JSON string.
type PostPolicy struct {
// Expiration date and time of the POST policy.
expiration time.Time
// Collection of different policy conditions.
conditions []policyCondition
// ContentLengthRange minimum and maximum allowable size for the
// uploaded content.
contentLengthRange struct {
min int64
max int64
}
// Post form data.
formData map[string]string
}
// NewPostPolicy - Instantiate new post policy.
func NewPostPolicy() *PostPolicy {
p := &PostPolicy{}
p.conditions = make([]policyCondition, 0)
p.formData = make(map[string]string)
return p
}
// SetExpires - Sets expiration time for the new policy.
func (p *PostPolicy) SetExpires(t time.Time) error {
if t.IsZero() {
return ErrInvalidArgument("No expiry time set.")
}
p.expiration = t
return nil
}
// SetKey - Sets an object name for the policy based upload.
func (p *PostPolicy) SetKey(key string) error {
if strings.TrimSpace(key) == "" || key == "" {
return ErrInvalidArgument("Object name is empty.")
}
policyCond := policyCondition{
matchType: "eq",
condition: "$key",
value: key,
}
if err := p.addNewPolicy(policyCond); err != nil {
return err
}
p.formData["key"] = key
return nil
}
// SetKeyStartsWith - Sets an object name that an policy based upload
// can start with.
func (p *PostPolicy) SetKeyStartsWith(keyStartsWith string) error {
if strings.TrimSpace(keyStartsWith) == "" || keyStartsWith == "" {
return ErrInvalidArgument("Object prefix is empty.")
}
policyCond := policyCondition{
matchType: "starts-with",
condition: "$key",
value: keyStartsWith,
}
if err := p.addNewPolicy(policyCond); err != nil {
return err
}
p.formData["key"] = keyStartsWith
return nil
}
// SetBucket - Sets bucket at which objects will be uploaded to.
func (p *PostPolicy) SetBucket(bucketName string) error {
if strings.TrimSpace(bucketName) == "" || bucketName == "" {
return ErrInvalidArgument("Bucket name is empty.")
}
policyCond := policyCondition{
matchType: "eq",
condition: "$bucket",
value: bucketName,
}
if err := p.addNewPolicy(policyCond); err != nil {
return err
}
p.formData["bucket"] = bucketName
return nil
}
// SetContentType - Sets content-type of the object for this policy
// based upload.
func (p *PostPolicy) SetContentType(contentType string) error {
if strings.TrimSpace(contentType) == "" || contentType == "" {
return ErrInvalidArgument("No content type specified.")
}
policyCond := policyCondition{
matchType: "eq",
condition: "$Content-Type",
value: contentType,
}
if err := p.addNewPolicy(policyCond); err != nil {
return err
}
p.formData["Content-Type"] = contentType
return nil
}
// SetContentLengthRange - Set new min and max content length
// condition for all incoming uploads.
func (p *PostPolicy) SetContentLengthRange(min, max int64) error {
if min > max {
return ErrInvalidArgument("Minimum limit is larger than maximum limit.")
}
if min < 0 {
return ErrInvalidArgument("Minimum limit cannot be negative.")
}
if max < 0 {
return ErrInvalidArgument("Maximum limit cannot be negative.")
}
p.contentLengthRange.min = min
p.contentLengthRange.max = max
return nil
}
// SetSuccessStatusAction - Sets the status success code of the object for this policy
// based upload.
func (p *PostPolicy) SetSuccessStatusAction(status string) error {
if strings.TrimSpace(status) == "" || status == "" {
return ErrInvalidArgument("Status is empty")
}
policyCond := policyCondition{
matchType: "eq",
condition: "$success_action_status",
value: status,
}
if err := p.addNewPolicy(policyCond); err != nil {
return err
}
p.formData["success_action_status"] = status
return nil
}
// SetUserMetadata - Set user metadata as a key/value couple.
// Can be retrieved through a HEAD request or an event.
func (p *PostPolicy) SetUserMetadata(key string, value string) error {
if strings.TrimSpace(key) == "" || key == "" {
return ErrInvalidArgument("Key is empty")
}
if strings.TrimSpace(value) == "" || value == "" {
return ErrInvalidArgument("Value is empty")
}
headerName := fmt.Sprintf("x-amz-meta-%s", key)
policyCond := policyCondition{
matchType: "eq",
condition: fmt.Sprintf("$%s", headerName),
value: value,
}
if err := p.addNewPolicy(policyCond); err != nil {
return err
}
p.formData[headerName] = value
return nil
}
// addNewPolicy - internal helper to validate adding new policies.
func (p *PostPolicy) addNewPolicy(policyCond policyCondition) error {
if policyCond.matchType == "" || policyCond.condition == "" || policyCond.value == "" {
return ErrInvalidArgument("Policy fields are empty.")
}
p.conditions = append(p.conditions, policyCond)
return nil
}
// Stringer interface for printing policy in json formatted string.
func (p PostPolicy) String() string {
return string(p.marshalJSON())
}
// marshalJSON - Provides Marshalled JSON in bytes.
func (p PostPolicy) marshalJSON() []byte {
expirationStr := `"expiration":"` + p.expiration.Format(expirationDateFormat) + `"`
var conditionsStr string
conditions := []string{}
for _, po := range p.conditions {
conditions = append(conditions, fmt.Sprintf("[\"%s\",\"%s\",\"%s\"]", po.matchType, po.condition, po.value))
}
if p.contentLengthRange.min != 0 || p.contentLengthRange.max != 0 {
conditions = append(conditions, fmt.Sprintf("[\"content-length-range\", %d, %d]",
p.contentLengthRange.min, p.contentLengthRange.max))
}
if len(conditions) > 0 {
conditionsStr = `"conditions":[` + strings.Join(conditions, ",") + "]"
}
retStr := "{"
retStr = retStr + expirationStr + ","
retStr = retStr + conditionsStr
retStr = retStr + "}"
return []byte(retStr)
}
// base64 - Produces base64 of PostPolicy's Marshalled json.
func (p PostPolicy) base64() string {
return base64.StdEncoding.EncodeToString(p.marshalJSON())
}