Configure Self-Managed MongoDB with Kerberos Authentication on Windows
Overview
MongoDB Enterprise supports authentication using a Kerberos service. Kerberos is an industry standard authentication protocol for large client/server systems. Kerberos allows MongoDB and applications to take advantage of existing authentication infrastructure and processes. MongoDB Enterprise only supports the MIT implementation of Kerberos.
Prerequisites
Setting up and configuring a Kerberos deployment is beyond the scope of
this document. This tutorial assumes have configured a Kerberos
service principal for each
mongod.exe
and mongos.exe
instance.
For replica sets and sharded clusters, ensure that your configuration uses fully qualified domain names (FQDN) rather than IP addresses or unqualified hostnames. You must use the FQDN for GSSAPI to correctly resolve the Kerberos realms and allow you to connect.
Procedures
Start mongod.exe
without Kerberos.
For the initial addition of Kerberos users, start
mongod.exe
without Kerberos support.
If a Kerberos user is already in MongoDB and has the
privileges required to create a user, you can start
mongod.exe
with Kerberos support.
Include additional settings as appropriate to your deployment.
Note
mongod
and mongos
bind to localhost by default. If the members of your deployment are
run on different hosts or if you wish remote clients to connect to
your deployment, you must specify --bind_ip
or
net.bindIp
.
Connect to mongod
.
Connect mongosh
to the mongod.exe
instance. If mongod.exe
has --auth
enabled, ensure
you connect with the privileges required to create a user.
Add Kerberos Principal(s) to MongoDB.
Add a Kerberos principal, <username>@<KERBEROS REALM>
, to
MongoDB in the $external
database. Specify the Kerberos realm in
ALL UPPERCASE. The $external
database allows
mongod.exe
to consult an external source (e.g. Kerberos)
to authenticate. To specify the user's privileges, assign
roles to the user.
To use Client Sessions and Causal Consistency Guarantees with $external
authentication users
(Kerberos, LDAP, or x.509 users), the usernames cannot be greater
than 10k bytes.
The following example adds the Kerberos principal
reportingapp@EXAMPLE.NET
with read-only access to the
records
database:
use $external db.createUser( { user: "reportingapp@EXAMPLE.NET", roles: [ { role: "read", db: "records" } ] } )
Add additional principals as needed. For every user you want to authenticate using Kerberos, you must create a corresponding user in MongoDB. For more information about creating and managing users, see User Management Commands.
Start mongod.exe
with Kerberos support.
You must start mongod.exe
as the service principal
account.
To start mongod.exe
with Kerberos support, set
the mongod.exe
parameter
authenticationMechanisms
to GSSAPI
:
mongod.exe --setParameter authenticationMechanisms=GSSAPI <additional mongod.exe options>
Include additional options as required for your configuration. For
instance, if you wish remote clients to connect to your deployment
or your deployment members are run on different hosts, specify the
--bind_ip
.
For example, the following starts a standalone mongod.exe
instance with Kerberos support:
mongod.exe --auth --setParameter authenticationMechanisms=GSSAPI --bind_ip localhost,<hostname(s)|ip address(es)>
Connect mongo.exe
shell to mongod.exe
and authenticate.
Connect the mongo.exe
shell client as the Kerberos
principal application@EXAMPLE.NET
.
You can connect and authenticate from the command line.
Using cmd.exe
:
mongo.exe --host hostname.example.net --authenticationMechanism=GSSAPI --authenticationDatabase=$external --username reportingapp@EXAMPLE.NET
Using Windows PowerShell
:
mongo.exe --host hostname.example.net --authenticationMechanism=GSSAPI --authenticationDatabase='$external' --username reportingapp@EXAMPLE.NET
If you are connecting to a system whose hostname matches the
Kerberos name, ensure that you specify the fully qualified
domain name (FQDN) for the --host
option, rather than an IP address or unqualified hostname.
If you are connecting to a system whose hostname does not
match the Kerberos name, first connect mongo.exe
to the mongod.exe
, and then from the
mongo.exe
shell, use the
db.auth()
method to authenticate in the $external
database.
use $external db.auth( { mechanism: "GSSAPI", user: "reportingapp@EXAMPLE.NET" } )
Additional Considerations
Configure mongos.exe
for Kerberos
To start mongos.exe
with Kerberos support, set the
mongos.exe
parameter authenticationMechanisms
to GSSAPI
. You must start mongos.exe
as the
service principal account:
mongos.exe --setParameter authenticationMechanisms=GSSAPI <additional mongos options>
Include additional options as required for your configuration. For
instance, if you wish remote clients to connect to your deployment
or your deployment members are run on different hosts, specify the
--bind_ip
.
For example, the following starts a mongos
instance with
Kerberos support:
mongos.exe --setParameter authenticationMechanisms=GSSAPI --configdb shard0.example.net, shard1.example.net,shard2.example.net --keyFile C:\<path>\mongos.keyfile --bind_ip localhost,<hostname(s)|ip address(es)>
Modify or include any additional mongos.exe
options as required
for your configuration. For example, instead of using
--keyFile
for internal authentication of sharded cluster
members, you can use x.509 member authentication instead.
Assign Service Principal Name to MongoDB Windows Service
Use setspn.exe
to assign the service principal name (SPN) to the
account running the mongod.exe
and the
mongos.exe
service:
setspn.exe -S <service>/<fully qualified domain name> <service account name>
Example
If mongod.exe
runs as a service named
mongodb
on testserver.mongodb.com
with the service account
name mongodtest
, assign the SPN as follows:
setspn.exe -S mongodb/testserver.mongodb.com mongodtest
Incorporate Additional Authentication Mechanisms
Kerberos authentication (GSSAPI (Kerberos)) can work alongside:
MongoDB's SCRAM authentication mechanism:
MongoDB's authentication mechanism for LDAP:
PLAIN (LDAP SASL)
MongoDB's authentication mechanism for x.509:
Specify the mechanisms as follows:
--setParameter authenticationMechanisms=GSSAPI,SCRAM-SHA-256
Only add the other mechanisms if in use. This parameter setting does not affect MongoDB's internal authentication of cluster members.
Testing and Verification
After completing the configuration steps, you can validate your
configuration with the mongokerberos
tool.
mongokerberos
provides a convenient method to verify your
platform's Kerberos configuration for use with MongoDB, and to test that
Kerberos authentication from a MongoDB client works as expected. See the
mongokerberos
documentation for more information.
mongokerberos
is available in MongoDB Enterprise only.