Configuring Kerberos Authentication for the Oozie Server

Create a Oozie service user principal using the syntax: oozie/<fully.qualified.domain.name>@<YOUR-REALM>. This principal is used to authenticate with the Hadoop cluster. where: fully.qualified.domain.name is the host where the Oozie server is running YOUR-REALM is the name of your Kerberos realm.
```
kadmin: addprinc -randkey oozie/fully.qualified.domain.name@YOUR-REALM.COM
```
Create a HTTP service user principal using the syntax: HTTP/<fully.qualified.domain.name>@<YOUR-REALM>. This principal is used to authenticate user requests coming to the Oozie web-services. where: fully.qualified.domain.name is the host where the Oozie server is running YOUR-REALM is the name of your Kerberos realm.
```
kadmin: addprinc -randkey HTTP/fully.qualified.domain.name@YOUR-REALM.COM
```
Important:
The HTTP/ component of the HTTP service user principal must be upper case as shown in the syntax and example above.

Create keytab files with both principals.

$ kadmin
kadmin: xst -k oozie.keytab oozie/fully.qualified.domain.name
kadmin: xst -k http.keytab HTTP/fully.qualified.domain.name

Merge the two keytab files into a single keytab file:

$ ktutil
ktutil: rkt oozie.keytab
ktutil: rkt http.keytab
ktutil: wkt oozie-http.keytab

Test that credentials in the merged keytab file work. For example:
```
$ klist -e -k -t oozie-http.keytab
```
Copy the oozie-http.keytab file to the Oozie configuration directory. The owner of the oozie-http.keytab file should be the oozie user and the file should have owner-only read permissions.

Edit the Oozie server oozie-site.xml configuration file in the Oozie configuration directory by setting the following properties:

Property	Value
`oozie.service.HadoopAccessorService.kerberos.enabled`	`true`
`local.realm`	`<REALM>`
`oozie.service.HadoopAccessorService.keytab.file`	`/etc/oozie/conf/oozie-http.keytab` for a package installation, or `<EXPANDED_DIR>/conf/oozie-http.keytab` for a tarball installation
`oozie.service.HadoopAccessorService.kerberos.principal`	`oozie/<fully.qualified.domain.name>@<YOUR-REALM.COM>`
`oozie.authentication.type`	`kerberos`
`oozie.authentication.kerberos.principal`	`HTTP/<fully.qualified.domain.name>@<YOUR-REALM.COM>`
`oozie.authentication.kerberos.name.rules`	Use the value configured for `hadoop.security.auth_to_local` in `core-site.xml`