Does Nifi 1.10 PutSplunk support Expression Language for the Port?

Question

Looking at the documentation for PutSplunk, it says that the Port "Supports Expression Language: true (will be evaluated using variable registry only)", does this mean I can't use expression language? Depending on the data in my flow, I want to have a single PutSplunk processor that handles the different ports I need to send my data to my Splunk instance.

Is there a way around this, because when I use ${splunkPort} in PutSplunk, I receive this error message: NumberFormatException: For input string""

For your convenience, here is the PutSplunk documentation link: https://nifi.apache.org/docs/nifi-docs/components/org.apache.nifi/nifi-splunk-nar/1.10.0/org.apache.nifi.processors.splunk.PutSplunk/

Answer 1

There is a variable registry option in nifi.properties. You can refer a file with this option such as

nifi.variable.registry.properties=test.txt

where the test.txt should have keys and values.

port=1234
url=abc.com

Then, you can refer to the variable port by ${port}.

Supports Expression Language: true (will be evaluated using variable registry only)

There are many types of variables but in this case, the variables from the registry only can be evaluated, that is the meaning.