Configure SPNEGO to Secure Web UIs in the Cluster

MapR uses the Simple and Protected GSSAPI Negotiation Mechanism (SPNEGO) to secure several Web UIs in the cluster, as well as the REST calls to the MapR Control System (MCS). The following procedure configures SPNEGO support for the web server nodes on your cluster.
  1. On each node in the cluster that will receive inbound SPNEGO traffic, generate a Kerberos principal with the user name HTTP, of the form HTTP/<webserver name>. Use the fully qualified domain name as the name in the principal. Although you could also use a short name or the IP address for the principal name, using the fully qualified domain name keeps the name consistent with principal names that generates and includes in the mapr.login.conf file.

    Whatever you use as the principal name is what users will have to match exactly in a browser to access the web pages that are protected. Note that several services and components in a MapR cluster handle SPNEGO traffic, including the MCS, JobTracker, TaskTracker, and HBase, among others.

    You can name the keytab file mapr.keytab if that file does not already exist.

    If the mapr.keytab file already exists, generate the new principal to a different file name and merge it to the mapr.keytab file using the ktutil tool:

            : addprinc -randkey HTTP/<webserver name>
            : ktadd -k /opt/mapr/conf/mapr.keytab HTTP/<webserver name>
  2. Verify that the /opt/mapr/conf/mapr.login.conf file lists the correct principal in the MAPR_WEBSERVER_KERBEROS section.
    Warning: To enable SPNEGO for MapR Control System (MCS) REST calls, on all nodes with the webserver role, add the following line to the /opt/mapr/conf/web.conf file:,basic
    Restart MCS to make the change take effect.

Testing SPNEGO with curl

This example tests that the MCS is using GSS for REST calls made with curl.

Use the following command to verify that your version of curl supports SPNEGO - under the “Features" header, the output of the command should show either GSS-Negotiate or SPNEGO - under the “Features” header, the output of the command should show either GSS-Negotiate or SPNEGO:
# curl --version 
curl 7.22.0 (x86_64-pc-linux-gnu) libcurl/7.22.0 OpenSSL/1.0.1 zlib/ libidn/1.23 librtmp/2.3 
Protocols: dict file ftp ftps gopher http https imap imaps ldap pop3 pop3s rtmp rtsp smtp smtps telnet tftp 
Features: GSS-Negotiate IDN IPv6 Largefile NTLM NTLM_WB SSL libz TLS-SRP
Verify that you have a valid Kerberos ticket-granting-ticket with the kinit -p <user> command, then test curl with the following command:
curl --negotiate -u : -b ~/cookiejar.txt -c ~/cookiejar.txt https://<web server node>:8443/rest/<API call> -k -v

This command returns HTTP/1.1 200 OK when curl is working correctly with SPNEGO.