This section describes how to enable relational connections to leverage your Hadoop Single Sign-On (SSO) infrastructure.When this feature is enabled and properly configured, users can create relational (JDBC) connections that use SSO that you have already configured. 

Connections that were created before this feature is enabled continue to operate as expected without modification.

Limitations

• For this release, this feature applies to SQL Server connections only.
• Cross-realm is not supported. As a result, the SQL Server instance, service principal, and 

  D s item
  item principal

   must be in the same Kerberos realm.

Pre-requisites

• Kerberos SSO: You must set up SSO authentication to the Hadoop cluster using Kerberos. This feature uses the global Kerberos keytab. For more information, see Set up for a Kerberos-enabled Hadoop cluster.

Enable

Configure

Configure JAAS file and path

JAAS file

For connections that support Kerberos-delegated authentication, the underlying driver supports a JAAS file in which you can provide environment-specific configuration to the driver. As needed, you can modify this file. 

Example JAAS file for SQL Server

Below is an example file, where you must apply the Kerberos global keytab and principal values that are to be used to authenticate to use the Kerberos-delegated connections of this type:

trifacta_jaas_config {
  com.sun.security.auth.module.Krb5LoginModule required
  useKeyTab=true
  storeKey=true
  doNotPrompt=true
  keyTab="</absolute/path/to/trifacta_jdbc_sso.keytab>"
  principal="<principal_name>";
};
 
JDBC_DRIVER_01 {
  com.sun.security.auth.module.Krb5LoginModule required debug=false
  useTicketCache=true;
};

where:

• keytab = the absolute path on the 

  D s item
  item node

   where the Kerberos global keytab is located.
• principal = Set to the service principal name of the user's service account in LDAP.

Specify Kerberos configuration file

On the 

<root>/etc/krb5.conf

If it doesn't exist, create it with the following content, some of which you must specify:

[libdefaults]
    default_realm = <my_default_realm>
    forwardable = true # Important that this is set!
  
[realms]
    <my_default_realm> = {
        kdc = <kdc_domain>
    }
  
[domain_realm]
    <my_domain> = <my_default_realm>

trifacta.com = TRIFACTA.COM

Modify the location of the Kerberos configuration file

If you need to move the location of the file from the default one, please complete the following:

Steps:

1. If you haven't already done so, copy the file from its current location to its preferred location. 

2. D s config

3. Specify the path to the new location in the following parameter:

   Code Block
   "webapp.connectivity.krb5Path": "/etc/krb5.conf";

   
   

4. Save your changes.

Local DNS configuration

The 

/etc/hosts

Add an entry in the following format:

<IP_address> <FQDN_to_KDC/AD-Server> <alias>

FQDN_to_KDC/AD-Server

Example:

127.255.255.255 ESNOEQ4-EC@BMBZ.trifacta.com ESNOEQ4-EC@BMBZ

Example Setup

The following example uses the default Kerberos realm to set an SSO connection to a SQL Server instance. This example is intended to demonstrate one way in which you can set up your SSO connections.

Steps:

1. Create the 

   D s item
   item service principal

   :
   1. Form: HTTP/serviceprincipal@REAM 
   2. Enable this flag: ok_to_auth_as_delegate 

   3. Example:

      Code Block
      kadmin -q "addprinc -randkey +ok_to_auth_as_delegate HTTP/serviceprincipal" kadmin -q "addprinc -randkey +ok_to_auth_as_delegate HTTP/serviceprincipal@REALM"

      
      

   4. For more information on delegation flags, see https://web.mit.edu/kerberos/krb5-1.12/doc/admin/admin_commands/kadmin_local.html

2. Generate a keytab for the 

   D s item
   item service principal

   .

3. Register the 

   D s item
   item service principal

    for Microsoft Sql Server instance:
   1. Enable this flag: ok_as_delegated 

   2. Example:

      Code Block
      kadmin -q "addprinc -randkey +ok_as_delegate MSSQLSvc/<FQDN>:<port>" kadmin -q "addprinc -randkey +ok_as_delegate MSSQLSvc/<FQDN>:<port>@REALM" kadmin -q "addprinc -randkey +ok_as_delegate MSSQLSvc/<FQDN>" kadmin -q "addprinc -randkey +ok_as_delegate MSSQLSvc/<FQDN>@REALM"

      
      

   3. For more information on setting this flag, see https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/register-a-service-principal-name-for-kerberos-connections?view=sql-server-2017.

4. Create a linked SQL Server account: 

   1. Account must have the same name as the end-user principal. 

   2. Account needs connect permissions at least.

Use

When you create a new connection of a supported type, you can select the Kerberos Delegate credentials type. When selected, no username or credentials are applied as part of the connection object. Instead, authentication is determined via Kerberos authentication with the cluster.

• Create SQL Server Connections

Sharing

When sharing SSO connections, the credentials for the connection cannot be shared for security reasons. The Kerberos principal for the user with whom the connection is shared is applied. That user must have the appropriate permissions to access any required data through the connection. See Overview of Sharing.