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Properties File Lookup Augmentation of Data Flow in Apache NiFi 1.7.x

A really cool technologist contacted me on LinkedIn and asked an interesting question

Tim,

How do I read values from a properties file and use them in my flow. I want to update/inject an attribute with this value.

If you don't want to use the Variable Registry, but want to inject a value from a properties file how to do it. You could run some REST server and read it or does some file reading hack. But we have a great service to do this very easily!

92663-lookupflow.png

In my UpdateAttribute (or in your regular attributes already), I have an attribute named, keytofind. This contains a lookup key such as an integer or a string key. We will find that value in the properties value and give you that in an attribute of your choosing.

92664-lookupattribute.png

We have a Controller Service to handle this for you. It reads from your specified properties file. Make sure Apache NiFi has permissions to that path and can read the file.

92665-lookupservic.png


PropertiesFileLookupService

https://nifi.apache.org/docs/nifi-docs/components/org.apache.nifi/nifi-lookup-services-nar/1.7.1/org...

We lookup the key specified in the “keytofind”. It returns a value that you specify as an extra attribute, mine is “updatedvalue”.

This is my properties file:

-rwxrwxrwx  1 tspann  staff  67 Oct  4 09:15 lookup.properties

stuff1=value1
stuff2=value2
stuff3=value other
tim=spann
nifi=cool

In this example, we are using the LookupAttribute processor. You can also use the LookupRecord processor depending on your needs.

Resources:

The Flow

lookup-from-properties-values.xml

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