NIFI-6703: Add Stateless NiFi to CLI

[SamHjelmfelt]

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Description of PR

https://issues.apache.org/jira/browse/NIFI-6703
Users should be able to easily run Stateless NiFi flows from the CLI without docker.

Added stateless bootstrap and nar to nifi-assembly and removed nifi-stateless/nifi-stateless-assembly. nifi-docker/dockermaven-stateless was updated to accommodate this change.

Added a new top level action (stateless) to nifi.sh which runs the "org.apache.nifi.stateless.NiFiStateless" bootstrap class with the provided arguments after extracting nars. Note that this is intentionally synchronous to allow for many stateless flows on the same machine.

Moved nifi-stateless into nifi-framework to resolve jar conflicts between traditional and stateless runtimes.

Updated stateless-nifi/README.md

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[SamHjelmfelt]

rebase

[mcgilman]

Will review...

[mcgilman]

Thanks for the PR @SamHjelmfelt! And thanks for the subsequent commit. This approach feels better and is inline with our existing approach with NiFi. Two additional comments.

1. When I build, the dockermaven-stateless fails because it seems to be running before nifi-assembly. Looking at the maven build order, it seems as though the order in the pom is a last resort. Something appears to be allowing the docker builds to run before the nifi-assembly. I think we should try to prevent this. I successfully did so by adding a dependency to nifi-docker (so all docker projects can benefit) on nifi-assembly.

<dependencies>
    <dependency>
        <groupId>org.apache.nifi</groupId>
        <artifactId>nifi-assembly</artifactId>
        <classifier>bin</classifier>
        <version>1.10.0-SNAPSHOT</version>
        <type>zip</type>
    </dependency>
</dependencies>

In order for this to work, I had to attach the resulting artifacts in the maven-assembly-plugin configuration of nifi-assembly. I am not sure if this is the best solution to this issue.

This is arguably a separate concern that we could file a JIRA for addressing in the future.

2. Once I got the build to execute in the right order, the dockermaven-stateless build seems to fail with:

[INFO] --- exec-maven-plugin:1.6.0:exec (Docker integration tests) @ dockermaven-stateless ---
[ERROR] Command execution failed.
java.io.IOException: Cannot run program "/Users/mgilman/Development/apache/nifi/nifi-docker/dockermaven-stateless/integration-test.sh"

This file appears to have been removed in this PR. Did you intend to also remove it from the pom?

[mcgilman]

I've created [1] to address (1) above in a subsequent effort.

[1] https://issues.apache.org/jira/browse/NIFI-6784

[mcgilman]

@SamHjelmfelt Can you please create follow JIRAs for the following:

1. Please add some support for configuring logging. Whe I am running your PR I am seeing lots of DEBUG output that I would like to disable. It's not clear/obvious how I can do that.

2. Please consider leveraging the extracted NARs in the same path that NiFi uses. Would definitely be open to updating where NiFi extracts NARs if it makes this easier for Stateless NiFi as well. Just seems unnecessary to extract the exact same NARs in an adjacent directory that NiFi uses.

[mcgilman]

I'm a +1 once the subsequent JIRAs are files and the documentation issues mentioned above are resolved.

[SamHjelmfelt]

Created JIRAs as requested by @mcgilman

1. https://issues.apache.org/jira/browse/NIFI-6788
2. https://issues.apache.org/jira/browse/NIFI-6789

[bbende]

+1 from me, was able to run the examples using local execution, docker with cat'd json, and docker with file json... will merge shortly