Can I directly use ${MPCONFIG=db_host} expression in web.xml using a property set in microprofile-config.properties ?

[Julien Sié]

Good afternoon.

I've noticed in Payara's documentation (https://docs.payara.fish/documentation/payara-server/server-configuration/var-substitution/types-of-variables.html and https://docs.payara.fish/documentation/payara-server/server-configuration/var-substitution/usage-of-variables.html) that it is possible to reference MicroProfile properties using the expression ${MPCONFIG=foo}.

I feel a little bit confused about the last sentence "MicroProfile properties need to be declared in one of the Payara defined config sources"...

I've declared the property "db_host=localhost" in the file microprofile-config.properties but this property doesn't seem loaded/resolved using it in web.xml.

However, I can load this property injecting the property in a bean (with @Inject @ConfigProperty(name="db_host")) and it works.

I've also followed the documentation and created a microprofile config property using the command asadmin set-config-property and the value is now resolved in the web.xml !

So, my question is : Is it possible to use a property defined in the file microprofile-config.properties in web.xml (a data-source for e.g.) or is it necessary to declare these properties using asadmin set-config-property command line ?

Thanks for your advises.

[Steve Millidge]

Hi 

As you have found out it is not possible to override a property in web.xml with a property set in an application microprofile-config.properties due to the order in which things are initialised when deploying an application. For example the first thing to happen is that the web.xml is parsed so the properties are not available at that point in time if stored in the war file whereas properties set at the system level are. 

Steve

[Julien Sié]

Thank you very much for your fast answer, Steve. 

It's pretty clear.

Anyway, I'll try to move the data-source definition from the web.xml into a @DataSourceDefinition annotation.
Is it the same behaviour? I mean the ${MPCONFIG=db_host} won't be parsed/resolved in the annotation?

[Steve Millidge]

To be honest I can't remember without trying it. I suspect the behaviour will be the same.

[Julien Sié]

... and you're right. Same behaviour.