90 lines
2.9 KiB
Go
90 lines
2.9 KiB
Go
|
/*
|
||
|
|
* MinIO Go Library for Amazon S3 Compatible Cloud Storage
|
||
|
|
* Copyright 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 credentials
|
||
|
|
|
||
|
|
// A Chain will search for a provider which returns credentials
|
||
|
|
// and cache that provider until Retrieve is called again.
|
||
|
|
//
|
||
|
|
// The Chain provides a way of chaining multiple providers together
|
||
|
|
// which will pick the first available using priority order of the
|
||
|
|
// Providers in the list.
|
||
|
|
//
|
||
|
|
// If none of the Providers retrieve valid credentials Value, ChainProvider's
|
||
|
|
// Retrieve() will return the no credentials value.
|
||
|
|
//
|
||
|
|
// If a Provider is found which returns valid credentials Value ChainProvider
|
||
|
|
// will cache that Provider for all calls to IsExpired(), until Retrieve is
|
||
|
|
// called again after IsExpired() is true.
|
||
|
|
//
|
||
|
|
// creds := credentials.NewChainCredentials(
|
||
|
|
// []credentials.Provider{
|
||
|
|
// &credentials.EnvAWSS3{},
|
||
|
|
// &credentials.EnvMinio{},
|
||
|
|
// })
|
||
|
|
//
|
||
|
|
// // Usage of ChainCredentials.
|
||
|
|
// mc, err := minio.NewWithCredentials(endpoint, creds, secure, "us-east-1")
|
||
|
|
// if err != nil {
|
||
|
|
// log.Fatalln(err)
|
||
|
|
// }
|
||
|
|
//
|
||
|
|
type Chain struct {
|
||
|
|
Providers []Provider
|
||
|
|
curr Provider
|
||
|
|
}
|
||
|
|
|
||
|
|
// NewChainCredentials returns a pointer to a new Credentials object
|
||
|
|
// wrapping a chain of providers.
|
||
|
|
func NewChainCredentials(providers []Provider) *Credentials {
|
||
|
|
return New(&Chain{
|
||
|
|
Providers: append([]Provider{}, providers...),
|
||
|
|
})
|
||
|
|
}
|
||
|
|
|
||
|
|
// Retrieve returns the credentials value, returns no credentials(anonymous)
|
||
|
|
// if no credentials provider returned any value.
|
||
|
|
//
|
||
|
|
// If a provider is found with credentials, it will be cached and any calls
|
||
|
|
// to IsExpired() will return the expired state of the cached provider.
|
||
|
|
func (c *Chain) Retrieve() (Value, error) {
|
||
|
|
for _, p := range c.Providers {
|
||
|
|
creds, _ := p.Retrieve()
|
||
|
|
// Always prioritize non-anonymous providers, if any.
|
||
|
|
if creds.AccessKeyID == "" && creds.SecretAccessKey == "" {
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
c.curr = p
|
||
|
|
return creds, nil
|
||
|
|
}
|
||
|
|
// At this point we have exhausted all the providers and
|
||
|
|
// are left without any credentials return anonymous.
|
||
|
|
return Value{
|
||
|
|
SignerType: SignatureAnonymous,
|
||
|
|
}, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// IsExpired will returned the expired state of the currently cached provider
|
||
|
|
// if there is one. If there is no current provider, true will be returned.
|
||
|
|
func (c *Chain) IsExpired() bool {
|
||
|
|
if c.curr != nil {
|
||
|
|
return c.curr.IsExpired()
|
||
|
|
}
|
||
|
|
|
||
|
|
return true
|
||
|
|
}
|