github.com/makyo/juju@v0.0.0-20160425123129-2608902037e9/worker/peergrouper/initiate.go (about)

     1  // Copyright 2014 Canonical Ltd.
     2  // Licensed under the AGPLv3, see LICENCE file for details.
     3  
     4  package peergrouper
     5  
     6  import (
     7  	"time"
     8  
     9  	"github.com/juju/errors"
    10  	"github.com/juju/replicaset"
    11  	"github.com/juju/utils"
    12  	"gopkg.in/mgo.v2"
    13  
    14  	"github.com/juju/juju/agent"
    15  	"github.com/juju/juju/mongo"
    16  )
    17  
    18  var initiateAttemptStrategy = utils.AttemptStrategy{
    19  	Total: 60 * time.Second,
    20  	Delay: 5 * time.Second,
    21  }
    22  
    23  // InitiateMongoParams holds parameters for the MaybeInitiateMongo call.
    24  type InitiateMongoParams struct {
    25  	// DialInfo specifies how to connect to the mongo server.
    26  	DialInfo *mgo.DialInfo
    27  
    28  	// MemberHostPort provides the address to use for
    29  	// the first replica set member.
    30  	MemberHostPort string
    31  
    32  	// User holds the user to log as in to the mongo server.
    33  	// If it is empty, no login will take place.
    34  	User     string
    35  	Password string
    36  }
    37  
    38  // InitiateMongoServer checks for an existing mongo configuration.
    39  // If no existing configuration is found one is created using Initiate.
    40  func InitiateMongoServer(p InitiateMongoParams) error {
    41  	logger.Debugf("Initiating mongo replicaset; dialInfo %#v; memberHostport %q; user %q; password %q", p.DialInfo, p.MemberHostPort, p.User, p.Password)
    42  	defer logger.Infof("finished InitiateMongoServer")
    43  
    44  	if len(p.DialInfo.Addrs) > 1 {
    45  		logger.Infof("more than one member; replica set must be already initiated")
    46  		return nil
    47  	}
    48  	p.DialInfo.Direct = true
    49  
    50  	// Initiate may fail while mongo is initialising, so we retry until
    51  	// we successfully populate the replicaset config.
    52  	var err error
    53  	for attempt := initiateAttemptStrategy.Start(); attempt.Next(); {
    54  		err = attemptInitiateMongoServer(p.DialInfo, p.MemberHostPort)
    55  		if err == nil {
    56  			logger.Infof("replica set initiated")
    57  			return err
    58  		}
    59  		if attempt.HasNext() {
    60  			logger.Debugf("replica set initiation failed, will retry: %v", err)
    61  		}
    62  	}
    63  	return errors.Annotatef(err, "cannot initiate replica set")
    64  }
    65  
    66  // attemptInitiateMongoServer attempts to initiate the replica set.
    67  func attemptInitiateMongoServer(dialInfo *mgo.DialInfo, memberHostPort string) error {
    68  	session, err := mgo.DialWithInfo(dialInfo)
    69  	if err != nil {
    70  		return errors.Annotatef(err, "cannot dial mongo to initiate replicaset")
    71  	}
    72  	defer session.Close()
    73  	session.SetSocketTimeout(mongo.SocketTimeout)
    74  
    75  	return replicaset.Initiate(
    76  		session,
    77  		memberHostPort,
    78  		mongo.ReplicaSetName,
    79  		map[string]string{
    80  			jujuMachineKey: agent.BootstrapMachineId,
    81  		},
    82  	)
    83  }