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Kerberos authentication and Thanos support in Grafana dashboards with Open Liberty

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Austin Bailey on Oct 23, 2020
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With Open Liberty you can now make use of the Kerberos authentication protocol to secure your JDBC data sources. The Open Liberty Grafana dashboard has also been updated to be able to visualize MicroProfile Metrics data from Thanos data sources.

In Open Liberty

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dependencies {
    libertyRuntime group: 'io.openliberty', name: 'openliberty-runtime', version: '[,)'

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Kerberos authentication for JDBC data sources

Kerberos is a network authentication protocol in which a client and server authenticate by communicating with a Key Distribution Center (KDC). Kerberos authentication may be used for JDBC data sources that are backed by one of the following databases:

  • IBM DB2

  • Oracle Database

  • Microsoft SQL Server

  • PostgreSQL

Kerberos authentication in Liberty builds on top of the Kerberos Login Module and JGSS API provided by the JDK, which in turn builds on top of the Kerberos OS libraries for the specific system being used.

The kerberos configuration element in server.xml provides system-wide configuration options for the Liberty server. For example:

  <kerberos keytab="${server.config.dir}/security/krb5.keytab" configFile="${server.config.dir}/security/krb5.conf"/>

The following example shows the Kerberos protocol being used to secure a data source:


  <!-- optional config: This is only needed if you need to customize the location of keytab or krb5.conf -->
  <kerberos keytab="${server.config.dir}/security/krb5.keytab" configFile="${server.config.dir}/security/krb5.conf"/>

  <authData id="myKerberosAuth" krb5Principal="krbUser"/>

  <library id="db2DriverLib">
    <fileset dir="${server.config.dir}/db2"/>

  <dataSource jndiName="jdbc/krb/basic" containerAuthDataRef="myKerberosAuth">
    <jdbcDriver libraryRef="db2DriverLib"/>
    <properties.db2.jcc databaseName="${DB2_DBNAME}" serverName="${DB2_HOSTNAME}" portNumber="${DB2_PORT}"/>

Before this release, it was technically possible to use Kerberos authentication with JDBC data sources, but the configuration was complex and un-documented. There was also previously a lack of connection pooling support when using Kerberos authentication for data sources.

Grafana dashboard support for Thanos data source

With Open Liberty the Open Liberty Grafana dashboard, which visualizes data from the MicroProfile Metrics feature, is now able to visualize data from a Thanos data source.

The Grafana dashboard provides a wide range of time-series visualizations of MicroProfile Metrics data such as CPU, Servlet, Connection Pool, and Garbage Collection metrics. It is powered by a Prometheus data source which is configured to ingest data from the /metrics endpoint of one or more Liberty servers, enabling you to view performance metrics in near real-time.

Previously, support has only been provided for visualizing metrics data with Grafana on Open Liberty servers that used Prometheus as the data source. In Kubernetes environments, such as the Red Hat OpenShift Container Platform, you can use Thanos to query and store metrics data from multiple clusters. The previous Grafana Dashboards would not work when Thanos was set as the data source, whereas the new Grafana dashboard allows users using Thanos as the data source to display metrics data.


For more information:

Significant bugs fixed in this release

We’ve spent some time fixing bugs in, including the following issues:

  • Server.xml config sources would not respect the "config_ordinal" property

    The MicroProfile Config specification allows for the ordinal of a built in config source to be changed by defining a property named config_ordinal which is read from that config source. However, built in config sources for server.xml variables and <appProperties> would not change their ordinal if a property with config_ordinal is set. This has now been corrected and built-in config sources will now update their ordinal when config_ordinal is set.

  • Wrong month returned when OffsetDateTime is used via EclipseLink 2.7

    Previously, a flaw existed within EclipseLink's implementation regarding the coversion of certain java.util and java.time types. Conversions between Calendar and LocalDate/LocalDateTime/OffsetDateTime did not account for the numeric indexing differences representing calendar months, resulting in inaccurate and invalid month conversions. This behaviour has now been corrected for Open Liberty and OffsetDateTime should now return a correct value consistently.

  • Unable to Override JAX-RS SecurityContext in ContainerRequestFilter

    Previously, you could not override the default SecurityContext in a ContainerRequestFilter. This means that it was not possible to override behavior of SecurityContext methods, which is especially useful for custom behavior with JSR 250 security annotations. Starting in, you are now able to override the SecurityContext in a ContainerRequestFilter with @Priority(AUTHORIZATION) via ContainerRequestContext.setSecurityContext(). This allows you greater flexibility to control authorization of your JAX-RS application with JSR 250 annotations.

  • Open Liberty Java security function did not grant default permissions from the JDK’s "java.policy" file to applications

    Included with any JDK is a java.policy file that allows Java code to access various system-specific actions, for example the ability to read system properties (i.e. Open Liberty would previously return an AccessControlException when attempting to use the System.getProperty() method to read the system properties that were permitted to be read. This behavior required application developers to grant these permissions in their applications' permissions.xml file or in the server.xml unnecessarily. This has now been fixed by ensuring that all of the java.policy permissions are imported into all code sources.

  • HTTP/1.1 and HTTP/2 behave differently when using a non-standard HTTP method

    Since release, Open Liberty has included full HTTP/2 support via Servlet 4.0. In past Open Liberty versions, the HTTP PATCH method, or any non-standard HTTP method, would return a HTTP 501 Not Implemented error when using HTTP/2. This has now been updated to allow the PATCH and other non-standard HTTP methods to be used with both HTTP/1.1 and HTTP/2 inside Open Liberty

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