How can we use UpdateAttribute processor for assigning variable of FlowFile content in Apache Nifi

Question

I need some help in UpdateAttribute processor: I have a CSV file which contains hostnames. I need to separate each hostname in the FlowFile and pass it as a variable to the REST API.
My REST API part is working fine when passing data manually. However, I didn't get how to pass a variable value as hostname in it.

Sharing sample file:

SRHAPP001,SRHWEBAPP002,SRHDB006,SRHUATAPP4,ARHUATDB98

Answer 1

I don't quite understand your goal, but I assume that you try to pass the hostname to your REST API module by using FlowFile variables.

You can achieve this by using the ExtractText-Processor. You simply use RegEx for separating your hostnames from the CSV file.

For more information, see https://nifi.apache.org/docs/nifi-docs/components/org.apache.nifi/nifi-standard-nar/1.12.1/org.apache.nifi.processors.standard.ExtractText/

How can I extract a substring from a flowfile data in Nifi?

If needed, you can split incoming FlowFiles on every hostname by using SplitContent-Processor