I am trying to understand how mongodb works with kerberos. To do that I have configured a kerberos server, just only for local. This is the configuration of my realm:

this is the content of krb5.conf file:

    default_realm = LOCALHOST

# The following krb5.conf variables are only for MIT Kerberos.
krb4_config = /etc/krb.conf
krb4_realms = /etc/krb.realms
kdc_timesync = 1
ccache_type = 4
forwardable = true
proxiable = true

v4_instance_resolve = false
v4_name_convert = {
        host = {
                rcmd = host
                ftp = ftp
        plain = {
                something = something-else
fcc-mit-ticketflags = true

        kdc = localhost
        admin_server = localhost
    krb4_convert = true
    krb4_get_tickets = false

And this is the content of kdc.conf file:

    kdc_ports = 750,88

        database_name = /var/lib/krb5kdc/principal
        admin_keytab = FILE:/etc/krb5kdc/kadm5.keytab
        acl_file = /etc/krb5kdc/kadm5.acl
        key_stash_file = /etc/krb5kdc/stash
        kdc_ports = 750,88
        max_life = 10h 0m 0s
        max_renewable_life = 7d 0h 0m 0s
        master_key_type = des3-hmac-sha1
        supported_enctypes = aes256-cts:normal arcfour-hmac:normal des3-hmac-sha1:normal des-cbc-crc:normal des:normal des:v4 des:norealm des:onlyrealm des:afs3
        default_principal_flags = +preauth

The kerberos seems to work fine. I created some principals (two users for test, one user for admin and one for the mongo server) and I tested that I can create tickets for each of them with kinit. This is the list of the principals:


The problem comes when I trying to start the mongodb service with the GSSAPI mechanism. The service never starts and I get this message:

2015-03-10T12:52:12.285+0100 ERROR: Couldn't find mech GSSAPI

2015-03-10T12:52:12.286+0100 SEVERE: Failed global initialization: BadValue SASL(-4): no mechanism available: Couldn't find mech GSSAPI

Of course, if I remove the authenticationMechanisms parameter, mongodb is started without no problems

Other information that could be useful:

  • The value of the krb5_ktname is /home/ardi/test/mongodb.keytab
  • The permissions of the keytab file are 777 (I know this is wrong but it is only for test)
  • My SO is ubuntu 14.04
  • I have this problem with the mongo enterprise versions 2.6.8 and 3.0.0

Does anyone of you have any idea where is the problem?

Thank you in advance for your time


1 Answer 1


I solved. The problem was that I did not have the library libsasl2-modules-gssapi-mit. Once I installed everything works fine

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