github.com/yrj2011/jx-test-infra@v0.0.0-20190529031832-7a2065ee98eb/prow/config/secrets_agent.go (about)

     1  /*
     2  Copyright 2018 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  // Implements an agent to read and reload the secrets.
    18  package config
    19  
    20  import (
    21  	"os"
    22  	"sync"
    23  	"time"
    24  
    25  	"github.com/sirupsen/logrus"
    26  )
    27  
    28  // SecretAgent watches a path and automatically loads the secrets stored.
    29  type SecretAgent struct {
    30  	sync.Mutex
    31  	secretsMap map[string][]byte
    32  }
    33  
    34  // Start will begin polling the secret file at the path. If the first load
    35  // fails, Start with return the error and abort. Future load failures will log
    36  // the failure message but continue attempting to load.
    37  func (sa *SecretAgent) Start(paths []string) error {
    38  	secretsMap, err := LoadSecrets(paths)
    39  	if err != nil {
    40  		return err
    41  	}
    42  
    43  	sa.secretsMap = secretsMap
    44  
    45  	// Start one goroutine for each file to monitor and update the secret's values.
    46  	for secretPath := range secretsMap {
    47  		go sa.reloadSecret(secretPath)
    48  	}
    49  
    50  	return nil
    51  }
    52  
    53  func (sa *SecretAgent) reloadSecret(secretPath string) {
    54  	var lastModTime time.Time
    55  	logger := logrus.NewEntry(logrus.StandardLogger())
    56  
    57  	skips := 0
    58  	for range time.Tick(1 * time.Second) {
    59  		if skips < 600 {
    60  			// Check if the file changed to see if it needs to be re-read.
    61  			secretStat, err := os.Stat(secretPath)
    62  			if err != nil {
    63  				logger.WithField("secret-path", secretPath).
    64  					WithError(err).Error("Error loading secret file.")
    65  				continue
    66  			}
    67  
    68  			recentModTime := secretStat.ModTime()
    69  			if !recentModTime.After(lastModTime) {
    70  				skips++
    71  				continue // file hasn't been modified
    72  			}
    73  			lastModTime = recentModTime
    74  		}
    75  
    76  		if secretValue, err := LoadSingleSecret(secretPath); err != nil {
    77  			logger.WithField("secret-path: ", secretPath).
    78  				WithError(err).Error("Error loading secret.")
    79  		} else {
    80  			sa.SetSecret(secretPath, secretValue)
    81  		}
    82  	}
    83  }
    84  
    85  // GetSecret returns the value of a secret stored in a map.
    86  func (sa *SecretAgent) GetSecret(secretPath string) []byte {
    87  	sa.Lock()
    88  	defer sa.Unlock()
    89  	return sa.secretsMap[secretPath]
    90  }
    91  
    92  // Set sets the map of secrets.
    93  func (sa *SecretAgent) SetSecret(secretPath string, secretValue []byte) {
    94  	sa.Lock()
    95  	defer sa.Unlock()
    96  	sa.secretsMap[secretPath] = secretValue
    97  }
    98  
    99  // GetTokenGenerator returns a function that gets the value of a given secret.
   100  func (sa *SecretAgent) GetTokenGenerator(secretPath string) func() []byte {
   101  	return func() []byte {
   102  		return sa.GetSecret(secretPath)
   103  	}
   104  }