NIFI-4424 org.apache.nifi.NiFi does not allow programmatic access to …

[peter-gergely-horvath]

…the NiFi engine

Thank you for submitting a contribution to Apache NiFi.

In order to streamline the review of the contribution we ask you
to ensure the following steps have been taken:

For all changes:

• Is there a JIRA ticket associated with this PR? Is it referenced
  in the commit message?

• Does your PR title start with NIFI-XXXX where XXXX is the JIRA number you are trying to resolve? Pay particular attention to the hyphen "-" character.

• Has your PR been rebased against the latest commit within the target branch (typically master)?

• Is your initial contribution a single, squashed commit?

Please note that the mvn -Pcontrib-check clean install failed with the following test case errororing out, which I believe to be a timing issue, that cannot be related to the change.
testStateTooLargeExceptionThrownOnReplace(org.apache.nifi.controller.state.providers.zookeeper.TestZooKeeperStateProvider) Time elapsed: 90.345 sec <<< ERROR! org.junit.runners.model.TestTimedOutException: test timed out after 20000 milliseconds.

For code changes:

• Have you ensured that the full suite of tests is executed via mvn -Pcontrib-check clean install at the root nifi folder?
• Have you written or updated unit tests to verify your changes?
• If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under ASF 2.0?
• If applicable, have you updated the LICENSE file, including the main LICENSE file under nifi-assembly?
• If applicable, have you updated the NOTICE file, including the main NOTICE file found under nifi-assembly?
• If adding new Properties, have you added .displayName in addition to .name (programmatic access) for each of the new properties?

For documentation related changes:

• Have you ensured that format looks appropriate for the output in which it is rendered?

Note:

Please ensure that once the PR is submitted, you check travis-ci for build issues and submit an update to your PR as soon as possible.

[patricker]

I'm still reviewing, but overall I don't see any issues, I see a lot of great next steps though.

This would probably be a general nifi.properties change, but having an option to not start the UI, Docs and ContentViewer WAR's and just run the API would be a good next step for an embedded solution; or allow any combination of those to be started/not started.

[peter-gergely-horvath]

Hi @patricker, please let me know if there is anything that requires clarification or if there is any way I could help the review. I would love to see this pull request being merged.

[patricker]

@peter-gergely-horvath Sorry for not getting back to you, I've been swamped. I tested out your changes and they are ready to merge.

I haven't merged anything since getting committer access. I'm going to work on figuring that out this week. Sorry for the delay...

[joewitt]

This looks fine to me (have a full clean build w/contrib check running but i expect it will be fine). Travis-CI would probably work fine now too given all the improvements that have been made.

I am fine with this change personally though. @markap14 and @alopresto as people that have worked on code in here please take a look and see if there is anything of concern. Otherwise either @patricker or i will merge. Thanks

[alopresto]

I don't see any breaking changes.

[peter-gergely-horvath]

@patricker, @joewitt Would it be possible for you to perform the merge? Based on my understanding, the changes have been approved by @alopresto.

I have some additional pull requests that depend on this one: it would be awesome to have this in the code base.

[alopresto]

@peter-gergely-horvath I will merge this today.

[alopresto]

Ran contrib-check and all tests pass. Fired up an instance of the application and it performed normally. +1, merging.