PutFile append file

Question

New to Nifi!

I'm wondering if there is a way in nifi to use a processor such as "PutFile" and have it write to one single file (append data to this file, or over-write the data in this file) - rather than create multiple different files? Is there another processor I need to use in order to accomplish this?

Answer 1

For those who don't want to override the data in the file but want to append data.

Appending to single file Using ExecuteStreamCommand processor:

It isn't possible with putFile processor but you can use the ExecuteStreamCommand processor to accomplish this.

In command arguments put attributes you want to log speparated by delimiter ${aatr1};${aatr2};${attr3}

In command path put the absolute path of a bash script: /path/logger.sh

logger.sh:

#!/bin/bash
echo "$1|$2|$3">> /path/attributes.log

attibutres.log will append the three attributes line by line. Make sure that the bash script is executable with nifi.

do a chmod 777 logger.sh

Appending to single file Using ExecuteScript Processor:

Try this ECMAscript:

var flowFile = session.get();
var File = Java.type("java.io.RandomAccessFile");
if (flowFile != null) {
    var filename = flowFile.getAttribute("filename");
    /// write to file
    var filePath = "/path/attributes.log" ;
    flowFile = session.putAttribute(flowFile, "filePath", filePath);
     var file = new File(filePath, "rws");
     file.seek(file.length());
        file.write(filename.getBytes());
        file.write("\n".getBytes());
        file.close();
    // Finish by transferring the FlowFile to an output relationship
    session.transfer(flowFile, REL_SUCCESS);
}