Greenplum Command Center Console can be secured by encrypting network traffic between the web server and users’ browsers, authenticating Command Center users, and managing users’ permissions to access Command Center features.
SSL/TLS Encryption
Greenplum Command Center supports SSL/TLS encryption to secure connections between browsers and the Command Center web server. Command Center supports TLS 1.2 protocol and higher. When enabled, Command Center uses the Secure WebSockets API, enabling long-lived, full-duplex connections, in addition to encryption.
To enable SSL/TLS encryption, you need a combined certificate/key file for the Command Center web server in place when you install Command Center. The file contains a private key and a server certificate.
You can request a key pair and certificate from your organization’s internal certificate authority or from an external certificate authority. You can also create a self-signed certificate with a cryptography suite such as OpenSSL. If you create a self-signed certificate, however, clients will have to override a security warning when they first connect to the Command Center web server.
To create the combined certificate/key file, create a text file, for example server.pem, and copy the entire body of private key and certificate into it. Make sure to include the beginning and end tags:
-----BEGIN RSA PRIVATE KEY-----
< private key >
-----END RSA PRIVATE KEY-----
-----BEGIN CERTIFICATE-----
< certificate >
-----END CERTIFICATE-----
You can concatenate additional certificates to the end of the file if a certificate chain is required to authenticate the server certificate.
Place the file on the server where Command Center will execute, for example in the /etc/ssl/certs directory of the VMware Greenplum coordinator host. When you install Command Center the installer prompts you to enter the full path to this file. See Command Center Console Parameters for details.
Authentication Options
Users logging in to Greenplum Command Center are authenticated with the VMware Greenplum host-based authentication system. Users can enter credentials as a user name and password or, if Kerberos authentication is configured, by authenticating with Kerberos on their workstation before browsing to the Command Center web server.
Note: Greenplum Command Center does not accept logins from the gpadmin user, or from users configured with trust authentication in the pg_hba.conf file.
Database users must first be added to the VMware Greenplum by using commands such as CREATE ROLE or CREATE USER. The LOGIN privilege is required. This example creates a login user with an encrypted password:
CREATE ROLE cc_user WITH LOGIN ENCRYPTED PASSWORD 'changeme';
The pg_hba.conf configuration file determines how authentication will proceed. This file contains a list of entries that are compared to attributes of the user’s connection request, including the type of connection, network location of the originating host, database name, and login user name. When a match is found, the authentication method specified in the entry is applied.
The pg_hba.conf file can be viewed by Operators and edited by Admins in the Command Center console on the Admin>Authentication page.
The md5 and password authentication methods authenticate the user name and password with the VMware Greenplum pg_roles system table. The md5 method requires the password to be MD5-encoded when sent over the network, so it is preferred over the password method, which sends the password in clear text.
The ldap authentication method authenticates the user name and password with an LDAP server. The LDAP server and parameters are specified in the options field of the pg_hba.conf entry. See the PostgreSQL LDAP authentication documentation for the format of the LDAP options.
The gss authentication method is used for Kerberos authentication. To use Kerberos with Command Center, Kerberos authentication must be enabled for the VMware Greenplum system and Command Center must also be configured. Users authenticate with the Kerberos KDC on their workstations (using kinit, for example) before connecting to the Command Center web server. The role name in Command Center is the user’s Kerberos principal name.
For details about setting up Kerberos authentication, see Enabling Kerberos Authentication with Greenplum Command Center.
See the PostgreSQL Authentication methods documentation for additional details of the authentication options.
Authorization
Note: The functionality described in this section has not been fully implemented in Greenplum Command Center 4.0.0. Only Admin and Self Only permission levels are available.
Command Center manages permission levels using VMware Greenplum roles and groups. The Basic, Operator Basic, and Operator permission levels correspond to the gpcc_basic, gpcc_operator_basic, and gpcc_operator group roles in the database. The Admin permission level is conferred to roles that have the SUPERUSER privilege. A user who has not been added to any of the groups and does not have SUPERUSER privilege has the most restrictive permission level, Self Only.
VMware Greenplum superusers can manage permission levels on the Command Center User Management page. Superusers can also directly assign users roles in the database by using the ALTER USER, ALTER GROUP, and related commands to add or remove users from groups and add or remove the SUPERUSER privilege. If a role is configured for more than one permission level, Command Center uses the highest permission level.
Command Center users have the following capabilities, according to their permission levels:
Self Only
Users can view metrics and view and cancel their own queries.
Any VMware Greenplum user successfully authenticated through the VMware Greenplum authentication system can access Greenplum Command Center with Self Only permission. Higher permission levels are required to view and cancel other’s queries and to access the System and Admin Control Center screens.
Basic
Allows users to view metrics, view all queries, and cancel their own queries.
Users with Basic permission are members of the VMware Greenplum gpcc_basic group.
Operator Basic
Allows users to view metrics, view their own and others’ queries, cancel their own queries, and view the System and Admin screens.
Users with Operator Read-only permission are members of the VMware Greenplum gpcc_operator_basic group.
Operator
Allows users to view their own and others’ queries, cancel their own and other’s queries, and view the System and Admin screens.
Users with Operator permission are members of the VMware Greenplum gpcc_operator group.
Admin
Allows users access to all views and capabilities in the Command Center.
VMware Greenplum users with the SUPERUSER privilege in VMware Greenplum have Superuser permissions in Command Center.
