github.com/letsencrypt/trillian@v1.1.2-0.20180615153820-ae375a99d36a/server/etcd_quota_provider.go (about)

     1  // Copyright 2018 Google Inc. All Rights Reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package server
    16  
    17  import (
    18  	"flag"
    19  	"fmt"
    20  
    21  	"github.com/golang/glog"
    22  	"github.com/google/trillian/quota"
    23  	"github.com/google/trillian/quota/cacheqm"
    24  	"github.com/google/trillian/quota/etcd/etcdqm"
    25  	"github.com/google/trillian/util/etcd"
    26  )
    27  
    28  // QuotaEtcd represents the etcd quota implementation.
    29  const QuotaEtcd = "etcd"
    30  
    31  var (
    32  	// EtcdServers is a flag containing the address(es) of etcd servers
    33  	EtcdServers = flag.String("etcd_servers", "", "A comma-separated list of etcd servers; no etcd registration if empty")
    34  	// TODO(Martin2112): suggested renaming these to etc_... to avoid clashes, but will it break existing deploys?
    35  	quotaMinBatchSize = flag.Int("quota_min_batch_size", cacheqm.DefaultMinBatchSize, "Minimum number of tokens to request from the quota system. "+
    36  		"Zero or lower means batching is disabled. Applicable for etcd quotas.")
    37  	quotaMaxCacheEntries = flag.Int("quota_max_cache_entries", cacheqm.DefaultMaxCacheEntries, "Max number of quota specs in the quota cache. "+
    38  		"Zero or lower means batching is disabled. Applicable for etcd quotas.")
    39  )
    40  
    41  func init() {
    42  	if err := RegisterQuotaManager(QuotaEtcd, newEtcdQuotaManager); err != nil {
    43  		glog.Fatalf("Failed to register quota manager %v: %v", QuotaEtcd, err)
    44  	}
    45  }
    46  
    47  func newEtcdQuotaManager() (quota.Manager, error) {
    48  	if *EtcdServers == "" {
    49  		return nil, fmt.Errorf("Can't create etcd quotamanager - etcd_servers flag is unset")
    50  	}
    51  	client, err := etcd.NewClient(*EtcdServers)
    52  	if err != nil {
    53  		return nil, fmt.Errorf("Failed to connect to etcd at %v: %v", *EtcdServers, err)
    54  	}
    55  
    56  	qm := etcdqm.New(client)
    57  	if *quotaMinBatchSize > 0 && *quotaMaxCacheEntries > 0 {
    58  		cachedQM, err := cacheqm.NewCachedManager(qm, *quotaMinBatchSize, *quotaMaxCacheEntries)
    59  		if err != nil {
    60  			return nil, err
    61  		}
    62  		qm = cachedQM
    63  	}
    64  	glog.Info("Using Etcd QuotaManager")
    65  	return qm, nil
    66  }