NIFI-272 - Create Maven Archetype for a Processor bundle

[bbende]

Creating the nifi-maven-archetypes module and adding the nifi-processor-bundle-archetype.

After running mvn clean install from nifi-maven-archetypes (or from nifi), you can test the archetype like this:

mvn archetype:generate -DarchetypeGroupId=org.apache.nifi -DarchetypeArtifactId=nifi-processor-bundle-archetype -DarchetypeVersion=0.0.1-incubating-SNAPSHOT -DgroupId=org.apache.nifi -DartifactId=donothing -Dversion=1.0

Using an artifactId of "donothing" will generate the following:

donothing (artifactId of nifi-donothing-bundle)
├── nifi-donothing-nar
│   └── pom.xml
├── nifi-donothing-processors
│   ├── pom.xml
│   └── src
│       ├── main
│       │   ├── java
│       │   │   └── org
│       │   │       └── apache
│       │   │           └── nifi
│       │   │               └── processors
│       │   │                   └── MyProcessor.java
│       │   └── resources
│       │       ├── META-INF
│       │       │   └── services
│       │       │       └── org.apache.nifi.processor.Processor
│       │       └── docs
│       │           └── org.apache.nifi.processors.MyProcessor
│       │               └── index.html
│       └── test
│           └── java
│               └── org
│                   └── apache
│                       └── nifi
│                           └── processors
│                               └── MyProcessorTest.java
└── pom.xml

[asfbot]

Mark Payne on dev@nifi.incubator.apache.org replies:
Bryan=2C
This is excellent. I pulled the patch and looked it over. Was looking at ma=
king just a few very minor tweaks to be a big more consistent with the code=
style that we typically use.
The only thing that I really would like to change -- and I dont know that w=
e can -- is that the artifact id becomes the name of the directory that the=
project goes into. So if I want to create a processor bundle called "fire"=
for instance I'd want to call it "nifi-fire-bundle" for the root directory=
. So I'd enter that as the artifact id. But then we want the sub-modules to=
be named "nifi-fire-processors" and "nifi-fire-nar" without the "-bundle" =
part there. I don't see any way to do this in Maven.
I considered maybe offering an 'artifact-base-name' property so that the su=
b-modules could be named '${artifact-base-name}-processors' and '${artifact=
-base-name}-nar' so that the artifact base name in this example would be 'n=
ifi-fire'.
Does anybody have a better approach for this?
Thanks-Mark
chetype for...
or-bundle-archetype.
ifi)=2C you can test the archetype like this:
hetypeArtifactId=3Dnifi-processor-bundle-archetype -DarchetypeVersion=3D0.0=
.1-incubating-SNAPSHOT -DgroupId=3Dorg.apache.nifi -DartifactId=3Ddonothing=
-Dversion=3D1.0
.Processor
ocessor
or-bundle-archetype.
your
e
please
=

[bbende]

Mark, I agree about the naming of the top level directory being annoying. I was thinking the same thing about having a second property so someone could do artifactId=donothing-bundle and artifactBaseName=donothing. I can play around with this more and see how it works and then submit an update.

[asfbot]

Mike Drob on dev@nifi.incubator.apache.org replies:
I'm not advocating either side in this, but do we want to explicitly

[asfbot]

Bryan Bende on dev@nifi.incubator.apache.org replies:
That is a good point, it may be possible to accept any package
name...Initially it was easier to force it to org.apache.nifi so that
META-INF/services/org.apache.nifi.processor.Processor and
docs/org.apache.nifi.processor.MyProcessor don't have to be dynamically
named, but it might be trivial to use the ${package} property provided to
name those files and directories appropriately, I just need to try it.

If that didn't work and we needed to force a package, we could also just
use some example package like "my.processor" (or anything not
org.apache.nifi) to avoid everyone using that by default.

As a starting point I'll see if the package can at least be dynamic, and
then go from there.

[asfbot]

Mark Payne on dev@nifi.incubator.apache.org replies:
Good call. I agree with this. One note, though, Bryan the file named org.apa=
che.nifi.processor.Processor will still keep that name because it's the full=
y qualified name of the Processor interface. But the contents of that file w=
ill change.=20

Sent from my iPhone
o
ow

[bbende]

So I was able to address the two items we discussed:

1. The artifactId will now be entered as the artifactId you want for the top-level artifact, so for example "nifi-donothing-bundle". An additional property called artifactBaseName will be specified that controls the sub-modules, in this example artifactBaseName would be set to "donothing" if you want to produce nifi-donothing-processors and nifi-donothing-nar.

   In order to get this to work I had to abandon the modules elements in the archetype descriptor in favor of using only filesets. The modules didn't seem to pick up the artifactBaseName property when doing replacement on the directories.

2. The archetype will now respect the package entered during archetype generation.

An updated example of using the archetype is the following:

mvn archetype:generate -DarchetypeGroupId=org.apache.nifi -DarchetypeArtifactId=nifi-processor-bundle-archetype -DarchetypeVersion=0.0.1-incubating-SNAPSHOT -DgroupId=org.apache.nifi -DartifactId=nifi-donothing-bundle -DartifactBaseName=donothing -Dpackage=my.test.processors -Dversion=1.0

[asfbot]

Mark Payne on dev@nifi.incubator.apache.org replies:
Bryan=2C
I pulled in your pull request=2C but I've not pushed it yet. I attached a p=
atch to https://issues.apache.org/jira/browse/NIFI-272 to account for the m=
ods that I made locally. Would like to have you review and see if you agree=
with the changes.
Basically=2C the the changes are:

• remove the tag from poms and just use the default=2C as this is wh=
  at I think we're moving to because so many of the artifacts are inconsisten=
  t with naming.* remove the default tag from the pom=2C as most=
  artifacts in the NiFi baseline don't have it* Set default package name to =
  ${groupId}.processors.${baseArtifactName}* Changed the default implementati=
  on of Processor's onTrigger to call session.get() and return if no FlowFile=
  . This is the first few lines of probably 80+% of Processors.
  We can change these changes if they're not desired. Otherwise=2C I will pus=
  h the changes.
  Thanks-Mark
  chetype for...
  3
  the top-level artifact=2C so for example "nifi-donothing-bundle". An additi=
  onal property called artifactBaseName will be specified that controls the s=
  ub-modules=2C in this example artifactBaseName would be set to "donothing" =
  if you want to produce nifi-donothing-processors and nifi-donothing-nar.
  in the archetype descriptor in favor of using only filesets. The modules di=
  dn't seem to pick up the artifactBaseName property when doing replacement o=
  n the directories.
  e generation.
  hetypeArtifactId=3Dnifi-processor-bundle-archetype -DarchetypeVersion=3D0.0=
  .1-incubating-SNAPSHOT -DgroupId=3Dorg.apache.nifi -DartifactId=3Dnifi-dono=
  thing-bundle -DartifactBaseName=3Ddonothing -Dpackage=3Dmy.test.processors =
  -Dversion=3D1.0
  your
  e
  please
  =

[bbende]

Mark, those changes in the patch look good to me.

I like the default value for the package property since it normally defaults to the groupId which is probably not what people would want.

And of course you know best about the standards across other bundles/processors in terms of the name elements and onTrigger methods.

Thanks!

[asfbot]

Mark Payne on dev@nifi.incubator.apache.org replies:
Bryan=2C
Sounds good. This has been pushed to develop.
Thanks again for the contribution!
-Mark
chetype for...
8
efaults to the groupId which is probably not what people would want.
processors in terms of the name elements and onTrigger methods.
your
e
please
=