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Authentication

Percona Backup for MongoDB has no authentication and authorization subsystem of its own - it uses MongoDB’s, i.e. pbm and pbm-agent only require a valid MongoDB connection URI string for the PBM user.

For the S3-compatible remote storage authentication config, see Percona Backup for MongoDB configuration in a cluster (or non-sharded replica set).

MongoDB connection strings - A Reminder (or Primer)

Percona Backup for MongoDB uses MongoDB Connection URI strings to open MongoDB connections. Neither pbm or pbm-agent accept legacy-style command-line arguments for --host, --port, --user, --password, etc. as the mongo shell or mongodump command does.

$ pbm-agent --mongodb-uri "mongodb://pbmuser:secretpwd@localhost:27018/?authSource=admin"
$ #Alternatively:
$ export PBM_MONGODB_URI="mongodb://pbmuser:secretpwd@localhost:27018/?authSource=admin"
$ pbm-agent
$ pbm list --mongodb-uri "mongodb://pbmuser:secretpwd@mongocsvr1:27018,mongocsvr2:27018,mongocsvr3:27018/?replicaSet=configrs&authSource=admin"
$ #Alternatively:
$ export PBM_MONGODB_URI="mongodb://pbmuser:secretpwd@mongocsvr1:27018,mongocsvr2:27018,mongocsvr3:27018/?replicaSet=configrs&authSource=admin"
$ pbm list

The connection URI above is the format that MongoDB drivers accept universally since approximately the release time of MongoDB server v3.6. The mongo shell accepts it too since v4.0. Using a v4.0+ mongo shell is a recommended way to debug connection URI validity from the command line.

Since Percona Backup for MongoDB must authenticate in MongoDB, we recommend specifying the authentication database associated with the pbm user’s credentials in the connection URI string using the authSource option.

The MongoDB Connection URI specification also allows specifying the authentication database via the defaultauthdb component. However, in this case, Percona Backup for MongoDB makes a backup of only this specified database.

If both authSource and defaultauthdb are unspecified, the authentication database defaults to the admin database.

The MongoDB Connection URI specification includes several non-default options you may need to use. For example the TLS certificates/keys needed to connect to a cluster or non-sharded replicaset with network encryption enabled are “tls=true” plus “tlsCAFile” and/or “tlsCertificateKeyFile” (see tls options).

Technical note

As of v1.0 the driver used by Percona Backup for MongoDB is the official v1.1 mongo-go-driver.

The pbm-agent connection string

pbm-agent processes should connect to their localhost mongod with a standalone type of connection.

The pbm connection string

The pbm CLI will ultimately connect to the replica set with the PBM control collections.

  • In a non-sharded replica set it is simply that replica set.

  • In a cluster it is the config server replica set.

You do not necessarily have to provide that connection string. If you provide a connection to any live node (shard, configsvr, or non-sharded replicaset member), it will automatically determine the right hosts and establish a new connection to those instead.

Tip

When running pbm from an unsupervised script, we recommend using a replica set connection string. A standalone-style connection string will fail if that mongod host happens to be down temporarily.