Host-Based Authentication (HBA)

This section explains how to configure CrateDB client connection and authentication.

Note

The stock crate.yml shipped with CrateDB explicitly enables host based authentication and defines a set of basic authentication rules.

If you do not want to use authentication, set auth.host_based.enabled to false. If authentication is disabled, user management remains active and you must specify the user crate (with an empty password) when connecting via the Postgres protocol. HTTP clients do not have to specify a user because they use the auth.trust.http_default_user if no user is provided.

Non-runtime cluster-wide settings must be configured the same on every node.

Authentication against CrateDB

Client access and authentication is configured via the auth.host_based.config setting in the crate.yml file.

The general format of the auth.host_based.config setting is a map of remote client access entries, where the key of the map defines the order in which the entries are used, which permit authentication to CrateDB. Each entry may contain no, one, or multiple fields. Allowed fields are user, ip or cidr, method, protocol and ssl. The description of these fields can be found in Trust authentication.

When a client sends an authentication request, CrateDB matches the provided username, IP address, protocol and connection scheme against these entries to determine which authentication method is required. If no entry matches, the client authentication request will be denied.

For HTTP connections the X-REAL-IP request header has priority over the actual client IP address in order to allow proxied clients to authenticate.

If auth.host_based is not set, the host based authentication is disabled. In this case CrateDB trusts all connections and accepts the user provided by the client given that this user exists.

If the setting auth.host_based is present and the configurations list does not contain any entry, then no client can authenticate.

For example, a host based configuration can look like this:

  1. auth:
  2.   host_based:
  3.     enabled: true
  4.     config:
  5.       0:
  6.         user: mike
  7.         address: 32.0.0.0/8
  8.         method: trust
  9.         protocol: pg
  10.       a:
  11.         user: barb
  12.         address: 172.16.0.0
  13.         protocol: pg
  14.         ssl: on
  15.       b:
  16.         user: crate
  17.         address: 32.0.0.0/8
  18.         method: trust
  19.       y:
  20.         user: eleven
  21.         protocol: pg
  22.       e:
  23.         user: dustin
  24.         address: 172.16.0.0
  25.         method: trust
  26.         protocol: http
  27.       f:
  28.         user: trinity
  29.         protocol: http
  30.         address: 127.0.0.1
  31.         ssl: off
  32.       z:
  33.         method: password

Note

In the auth.host_based.config setting, the order of the entries is defined by the natural order of the group keys of the setting. The authentication method of the first entry that matches the client user and address will be used. If the authentication attempt fails, subsequent entries will not be considered. The entry look-up order is determined by the order identifier of each entry.

In the example above:

{user: mike, address: 32.0.0.0/8, method: trust, protocol: pg} means that the user mike can authenticate to CrateDB over the Postgres Wire Protocol from any IP address ranging from 32.0.0.0 to 32.255.255.255, using the trust authentication method.

{user: crate, address: 32.0.0.0/8, method: trust} means that the superuser crate can authenticate to CrateDB over the protocols for which authentication is supported from any IP address in the range of 32.0.0.0 to 32.255.255.255, using the trust authentication method.

{user: barb, address: 172.16.0.0, protocol: pg, ssl: on} means that the user barb can authenticate to CrateDB over the Postgres Wire Protocol from the 172.16.0.0 IP Address only if the connection is done over SSL/TLS. Since no authentication method is specified, the trust method will be used by default.

The entry: {user: eleven, protocol: pg} means that the user eleven can authenticate to CrateDB over the Postgres Wire Protocol from any IP address, using the trust method.

{user: dustin, address: 172.16.0.0, protocol: http, method: trust} means that the user dustin can authenticate to CrateDB over HTTP protocol from the 172.16.0.0 IP Address using the trust method.

{user: trinity, address: 127.0.0.1, protocol: http, ssl: off} means that the user trinity can authenticate to CrateDB over HTTP from the 127.0.0.1 IP Address only if no SSL/TLS connection is used. Since no authentication method is specified, the trust method will be used by default.

And finally the entry {method: password} means that any existing user (or superuser) can authenticate to CrateDB from any IP address using the password method for both HTTP and PostgreSQL wire protocol.

Note

For general help managing users, see User management.

Authenticating as a superuser

When CrateDB is started, the cluster contains one predefined superuser. This user is called crate.

To enable trust authentication for the superuser, crate must be specified in the the auth.host_based setting, like this:

  1. auth:
  2.   host_based:
  3.     enabled: true
  4.     config:
  5.       0:
  6.         user: crate

Authenticating to Admin UI

When trying to access the CrateDB admin UI, authentication with the user defined with the auth.trust.http_default_user setting (defaults to crate) will be attempted initially. If this authentication attempt fails, the browser will open the standard popup window where the user is asked to fill in credentials. Depending on the HBA configuration, it may be necessary to a username and password, or, alternatively, a username only.

Users that log in to the admin UI must be granted DQL` privileges at the CLUSTER level in order to be able to access the various monitoring sections. For example:

  1. cr> GRANT DQL TO admin;
  2. GRANT OK, 1 row affected (... sec)

For more information, consult the privileges section.

Node-to-node communication

You can use the Host-Based Authentication mechanism for node-to-node communication.

For example, if you wanted to configure a multi-zone cluster, you should enable certificate authentication like this:

  1. auth:
  2.   host_based:
  3.     enabled: true
  4.     config:
  5.       0:
  6.         protocol: transport
  7.         ssl: on
  8.         method: cert

Note

CrateDB only supports the trust and cert authentication methods for node-to-node communication.