With Open Liberty, how to use an environment variable as an application property?-CodePudding

I expected to be able to do something like this in my server.xml, but I could not get it to work:

<variable name="my.ldap.url" value="${LDAP_URL}" />

Setting it in jvm.options or server.env do not seem to be options either from what I can tell. Neither of those are parsing environment variables from my tests.

-Dmy.ldap.url=$LDAP_URL

Setting properties in my own files and using environment variables did not seem to work either. I tried something like this in my server.xml

<library id="configs">
    <fileset dir="${server.config.dir}/configs" includes="*.properties" />
</library>

So I'm just lost for ideas right now. How do I take environment variables and inject them into an Open Liberty application as application properties?

I searched high and low for documentation on this, with no success.

In Jboss I was able to accomplish simple via

bin/standalone.sh -Dmy.ldap.url=$LDAP_URL

CodePudding user response：

It should work for you exactly the way it does in Jboss:

wlp/bin/server start server1 -Dmy.ldap.url=$LDAP_URL

Your <variable> definition would create a Liberty configuration variable that resolves to the value of LDAP_URL in the environment, but it would not be set as a java system property.

If you're still seeing problems with passing the value on the command line you could check all java system properties by running:

wlp/bin/server dump {server name}

In the output zip file, the dump_{timestamp}/introspections/JavaRuntimeInformation.txt will show both the command line arguments and all defined java system properties.

CodePudding user response：

I'd consider using Microprofile config, checkout this guide and see it does answer your questions.

It shows you how to inject variables using following schema:

@Inject @ConfigProperty(name="port")
private int port;

assuming there is PORT env entry in your system.

You can also use env variables in server configuration using server.xml for example:

<properties.db2.jcc serverName="${JDBC_HOST}" portNumber="${JDBC_PORT}" databaseName="${JDBC_DB}" sslConnection="${JDBC_SSL}"
            user="${JDBC_ID}" password="${JDBC_PASSWORD}"/>

Details here https://openliberty.io/docs/latest/reference/config/server-configuration-overview.html

For your library point you would have to add it to your application via classloader, so I wouldn't recommend that. Like this:

<application name="myapp" type="ear" location="myapp.ear">
  <classloader commonLibraryRef="configs" />
</application>

Hope it solves your problems.