Apache NiFi With Rule Engine

Combining Apache NiFi with Rule engine is easy and fun. You can do some really great stuff with data manipulation, and I wrote some code for that purpose using Drools.

Build or Download Rule Engine

Download a compiled NiFi NAR here or Build from https://github.com/alefbt/NiFi-Rule-engine-processor

This is currently working only with JSON flow files.

(Licence: Apache2)

Then run the following: 

git clone https://github.com/alefbt/NiFi-Rule-engine-processor
cd NiFi-Rule-engine-processor
mvn clean install package
cp nifi-ruleengien-processor-nar/target/nifi-ruleengien-processor-1.0.nar /path-to-nifi/lib/

And (re)start NiFi.

Example

Create a NiFi Flow

1. GetFile Processor
   • Set property `source folder` : /some-project-path/IN
2. RuleEngineProcessor
   • Set the property DRL file path to /some-project-path/DRL/business_object_json_test1.drl
3. PutFile Processor
   • Set the property `dest folder` to /some-project-path/OUT

Create Files and Relevant Folders

Create a DRL file /some-project-path/DRL/business_object_json_test1.drl

package com.matrixbi.rules

import com.matrixbi.objects.BusinessObject

rule "Good Morning"
when
b: BusinessObject()
eval( b.getAsInt("time") < 12 )
then
b.set("greet","G00d Morning " + b.get("name")); 
end

rule "Good Afternoon"
when
b: BusinessObject()
eval(b.getAsInt("time") >=12 && b.getAsInt("time") < 16)
then
b.set("greet","Good Afternoon " + b.get("name"));
end

rule "Good Night"
when
b: BusinessObject()
eval(b.getAsInt("time") >= 16)
then
b.set("greet","Good Afternoon " + b.get("name"));
end

Create a JSON test file /some-project-path/IN/business_object_json_test1.json

{
"time": 11,
"greet": "Default text",
"name":"Yehuda"
}

Activate all and run it.

Result

After a few moments, you should see business_object_json_test1.json in the/some-project-path/OUT folder file.

Source

Result