Below are two example config YAML files. The first tails the minifi-app.log, send the tailed log and provenance data back to a secure instance of NiFi. The second uses a series of processors to tail the app log, routes off only lines that contain "WriteAheadFlowFileRepository" and puts it as a file in the "./" directory.

MiNiFi Config Version: 1
Flow Controller:
    name: MiNiFi Flow
    comment:

Core Properties:
    flow controller graceful shutdown period: 10 sec
    flow service write delay interval: 500 ms
    administrative yield duration: 30 sec
    bored yield duration: 10 millis

FlowFile Repository:
    partitions: 256
    checkpoint interval: 2 mins
    always sync: false
    Swap:
        threshold: 20000
        in period: 5 sec
        in threads: 1
        out period: 5 sec
        out threads: 4

Provenance Repository:
    provenance rollover time: 1 min

Content Repository:
    content claim max appendable size: 10 MB
    content claim max flow files: 100
    always sync: false

Component Status Repository:
    buffer size: 1440
    snapshot frequency: 1 min

Security Properties:
    keystore: /tmp/ssl/localhost-ks.jks
    keystore type: JKS
    keystore password: localtest
    key password: localtest
    truststore: /tmp/ssl/localhost-ts.jks
    truststore type: JKS
    truststore password: localtest
    ssl protocol: TLS
    Sensitive Props:
        key:
        algorithm: PBEWITHMD5AND256BITAES-CBC-OPENSSL
        provider: BC

Processors:
    - name: TailFile
      class: org.apache.nifi.processors.standard.TailFile
      max concurrent tasks: 1
      scheduling strategy: TIMER_DRIVEN
      scheduling period: 1 sec
      penalization period: 30 sec
      yield period: 1 sec
      run duration nanos: 0
      auto-terminated relationships list:
      Properties:
          File to Tail: logs/minifi-app.log
          Rolling Filename Pattern: minifi-app*
          Initial Start Position: Beginning of File

Connections:
    - name: TailToS2S
      source name: TailFile
      source relationship name: success
      destination name: 8644cbcc-a45c-40e0-964d-5e536e2ada61
      max work queue size: 0
      max work queue data size: 1 MB
      flowfile expiration: 60 sec
      queue prioritizer class: org.apache.nifi.prioritizer.NewestFlowFileFirstPrioritizer

Remote Processing Groups:
    - name: NiFi Flow
      comment:
      url: https://localhost:8090/nifi
      timeout: 30 secs
      yield period: 10 sec
      Input Ports:
          - id: 8644cbcc-a45c-40e0-964d-5e536e2ada61
            name: tailed log
            comments:
            max concurrent tasks: 1
            use compression: false

Provenance Reporting:
    comment:
    scheduling strategy: TIMER_DRIVEN
    scheduling period: 30 sec
    destination url: https://localhost:8090/
    port name: provenance
    originating url: http://${hostname(true)}:8081/nifi
    use compression: true
    timeout: 30 secs
    batch size: 1000

Flow Controller:
    name: MiNiFi Flow
    comment:

Core Properties:
    flow controller graceful shutdown period: 10 sec
    flow service write delay interval: 500 ms
    administrative yield duration: 30 sec
    bored yield duration: 10 millis
    max concurrent threads: 1

FlowFile Repository:
    partitions: 256
    checkpoint interval: 2 mins
    always sync: false
    Swap:
        threshold: 20000
        in period: 5 sec
        in threads: 1
        out period: 5 sec
        out threads: 4

Content Repository:
    content claim max appendable size: 10 MB
    content claim max flow files: 100
    always sync: false

Component Status Repository:
    buffer size: 1440
    snapshot frequency: 1 min

Security Properties:
    keystore: /tmp/ssl/localhost-ks.jks
    keystore type: JKS
    keystore password: localtest
    key password: localtest
    truststore: /tmp/ssl/localhost-ts.jks
    truststore type: JKS
    truststore password: localtest
    ssl protocol: TLS
    Sensitive Props:
        key:
        algorithm: PBEWITHMD5AND256BITAES-CBC-OPENSSL
        provider: BC

Processors:
    - name: TailAppLog
      class: org.apache.nifi.processors.standard.TailFile
      max concurrent tasks: 1
      scheduling strategy: TIMER_DRIVEN
      scheduling period: 10 sec
      penalization period: 30 sec
      yield period: 1 sec
      run duration nanos: 0
      auto-terminated relationships list:
      Properties:
          File to Tail: logs/minifi-app.log
          Rolling Filename Pattern: minifi-app*
          Initial Start Position: Beginning of File
    - name: SplitIntoSingleLines
      class: org.apache.nifi.processors.standard.SplitText
      max concurrent tasks: 1
      scheduling strategy: TIMER_DRIVEN
      scheduling period: 0 sec
      penalization period: 30 sec
      yield period: 1 sec
      run duration nanos: 0
      auto-terminated relationships list:
          - failure
          - original
      Properties:
          Line Split Count: 1
          Header Line Count: 0
          Remove Trailing Newlines: true
    - name: RouteErrors
      class: org.apache.nifi.processors.standard.RouteText
      max concurrent tasks: 1
      scheduling strategy: TIMER_DRIVEN
      scheduling period: 0 sec
      penalization period: 30 sec
      yield period: 1 sec
      run duration nanos: 0
      auto-terminated relationships list:
          - unmatched
          - original
      Properties:
          Routing Strategy: Route to 'matched' if line matches all conditions
          Matching Strategy: Contains
          Character Set: UTF-8
          Ignore Leading/Trailing Whitespace: true
          Ignore Case: true
          Grouping Regular Expression:
          WALFFR: WriteAheadFlowFileRepository
    - name: PutFile
      class: org.apache.nifi.processors.standard.PutFile
      max concurrent tasks: 1
      scheduling strategy: TIMER_DRIVEN
      scheduling period: 0 sec
      penalization period: 30 sec
      yield period: 1 sec
      run duration nanos: 0
      auto-terminated relationships list:
          - failure
          - success
      Properties:
          Directory: ./
          Conflict Resolution Strategy: replace
          Create Missing Directories: true
          Maximum File Count:
          Last Modified Time:
          Permissions:
          Owner:
          Group:

Connections:
    - name: TailToSplit
      source name: TailAppLog
      source relationship name: success
      destination name: SplitIntoSingleLines
      max work queue size: 0
      max work queue data size: 1 MB
      flowfile expiration: 60 sec
      queue prioritizer class: org.apache.nifi.prioritizer.NewestFlowFileFirstPrioritizer
    - name: SplitToRoute
      source name: SplitIntoSingleLines
      source relationship name: splits
      destination name: RouteErrors
      max work queue size: 0
      max work queue data size: 1 MB
      flowfile expiration: 60 sec
      queue prioritizer class: org.apache.nifi.prioritizer.NewestFlowFileFirstPrioritizer
    - name: RouteToS2S
      source name: RouteErrors
      source relationship name: matched
      destination name: PutFile
      max work queue size: 0
      max work queue data size: 1 MB
      flowfile expiration: 60 sec
      queue prioritizer class: org.apache.nifi.prioritizer.NewestFlowFileFirstPrioritizer

Provenance Reporting:
    comment:
    scheduling strategy: TIMER_DRIVEN
    scheduling period: 30 sec
    destination url: https://localhost:8080/
    port name: provenance
    originating url: http://${hostname(true)}:8081/nifi
    use compression: true
    timeout: 30 secs
    batch size: 1000