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Last pushed: a year ago
Short Description
Kerberos and LDAP
Full Description

Docker kerberos

This image
is designed to support the Hadoop clusters launched by Cloudbreak. The default realm is NODE.DC1.CONSUL and the default admin principal is admin/admin. All the default values can be modified with environment variables.


The image can be started in bootstrap mode and non-bootstrap mode. Bootstrap mode means
when the container is launched it will create the DB for kerberos along with the admin user and start the KDC.
This use-case is convenient for a quick start. The non-bootstrap mode relies on that a third party will do the necessary steps to create the appropriate principals thus the KDC will start only once they are created.
Cloudbreak does this with a consul plugn.

Quick start

docker run -d --net=host -v /etc/krb5.conf:/etc/krb5.conf -v /dev/urandom:/dev/random --name kerberos -e BOOTSTRAP=0 sequenceiq/kerberos

The containers have a pretty bad entropy level so the KDC won't start because of this. We can overcome this by using /dev/urandom which is less secure but does not care about entropy.
The /etc/krb5.conf is shared with the host so the generated configuration will be present on the host as well. We need to share this configuration with the ambari-server container as well or you need to take care of the copying.
Once the container is running you can enable kerberos with Ambari.

Useful environment variables:

Environmenr variables Description
REALM the Kerberos realm
DOMAIN_REALM the DNS domain for the realm
KERB_MASTER_KEY master key for the KDC
KERB_ADMIN_USER administrator account name
KERB_ADMIN_PASS administrator's password
SEARCH_DOMAINS domain suffix search list
LDAP_DC domain suffix search list
LDAP_USER ldap user
LDAP_PASS ldap pass
LDAP_URL ldap url


Once kerberos is enabled you need a ticket to execute any job on the cluster. Here's an example to get a ticket:

kinit -V -kt /etc/security/keytabs/smokeuser.headless.keytab ambari-qa-sparktest-rec@NODE.DC1.CONSUL

Example job:

export HADOOP_LIBS=/usr/hdp/current/hadoop-mapreduce-client
export JAR_EXAMPLES=$HADOOP_LIBS/hadoop-mapreduce-examples.jar
export JAR_JOBCLIENT=$HADOOP_LIBS/hadoop-mapreduce-client-jobclient.jar

hadoop jar $JAR_EXAMPLES teragen 10000000 /user/ambari-qa/terasort-input

hadoop jar $JAR_JOBCLIENT mrbench -baseDir /user/ambari-qa/smallJobsBenchmark -numRuns 5 -maps 10 -reduces 5 -inputLines 10 -inputType ascending
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