Yup, and it's where karaf-boot is interesting.
Let me move forward by providing a serie of karaf-boot-starter* (as BoM)
and corresponding samples.
I gonna enhance the annotations too, providing more higher level.
Regards
JB
On 09/11/2015 11:28 AM, Achim Nierbeck wrote:
Hey guys,
yes we all are walking the same path.
I can't tell you how much dislike I have right now for that micro-monolith
hype everyone is following like a Lemming!
And I fully agree with what Milen talked about. It's more to the point that
a lot of people that used to be very OSGi friendly
turned away and now walk the same path. One of them is a colleague of mine.
We need more talks about how awesome Karaf and OSGi is, but on the other
side we need to face those "dislikes" and need to take those as a challenge
for improvement.
Right now I'd say the most important way of achieving this is to make it
easier to start with.
And this is the point we already agreed on with the *-starter BOMs.
Lust but not least we need to get louder ... and this is where we need the
community of users to actually publish blogs, make noise to let people know
how good the software is that it uses. Also for those "micorservice"
use-cases :D
regards, Achim
2015-09-11 10:21 GMT+02:00 Jean-Baptiste Onofré <[email protected]>:
Great feedback Milen ! and I agree with your points.
My feeling is the same:
1/ Karaf is an awesome container, for sure ;)
2/ maybe developers will be disappointed by "monolithic" approaches, but
for now, there are more and more devs going to spring-boot, dropwizard, or
whatever. The only reason is: "it's easy".
3/ my "frustration" comes from the fact that we know Karaf/OSGi values,
but honestly, it's not easy to dev on it for beginners.
So, I don't want to provide the same thing as spring-boot: I just try to
figure out a way to simplify first steps for new developers on Karaf ;)
Regards
JB
On 09/11/2015 10:13 AM, Milen Dyankov wrote:
I need to partly agree with Achim. I mean I would probably fully agree if
I
was to accept the initial problem is as he describe it. But personally I
think it's slightly different. I acknowledge the fact that I may be wrong
in my judgement but here is what it is based on:
- I have been working with Java EE for the last 15 years
- I have been "in love" with OSGi for the last 6-7 years but never used
it
for anything big (as Achim mentioned, other technologies pay my bills)
- up until last year OSGi was not part of my day job, and even today it
still is not a major part
- it's been about 3 years, since the company I work for started
migrating
huge EE project to OSGi. Since then, as a consultant, I've have had a
countless discussions with customers and partners about motivation,
worries, challenges, expectations, ...
So from this perspective I think people outside of OSGi simply don't
understand what OSGi is about. And we (all OSGi fans) and not doing nearly
enough to explain it. Bah, some well known and respected sources
<https://www.thoughtworks.com/radar/platforms/osgi> claims OSGi is
practically dead and advises to go "microservices way" or "wait for
Jigsaw". I spent the last year attending conferences and talking about how
OSGi is valuable alternative to microservices and why. And I can tell you
from experience, getting a OSGi talk accepted on a respectful Java
conference is a huge challenge.
So what I sense now is "lets use the microsevices hype to make people
shift
to OSGi / Karaf". And to do that, let's make it easy. And to make it easy,
let's hide from them the only thing that makes OGSi stand out - real
dynamic modularity! This may even work, but is that what we really want?
SpringBoot, Docker, Kubernetes, ... are great technologies that make
people
think they can do distributed computing without knowing anything about
distributed computing! If you ask me, the fall of disappointment is
coming,
we just don't see it yet. And it's not because those technologies are bad.
It's because they made people thing that something that is hard, can be
solved with a bunch of annotations and wrappers. I'm blown away by the
fact
there are so many developers out there that believe in magic.
I personally don't want to go down that road. For me the real power of
OSGi
is building truly dynamic modular systems than can start as "monoliths"
and
scale out to distributed. The fact that one needs to learn to deal with
the
dynamism even when everything runs inside a single JVM makes it so much
easier to scale out when the right time comes. Take away (or hide) it from
me and I have absolutely no reason to choose OSGi over JEE. Why should I?
Apart from that one thing JEE ca do everything OSGi can do! JEE community
is by far larger! It's THE "standard"! It's on every single Java
conference! It now supports microservices (if you don't believe me just
watch some recent talk from RedHat fellows)! And with Java 9 on the
horizon, more and more people will be speaking about Jigsaw and how it is
the way to go.
I don't think the response to that should be "hey we do microservies as
well" or "hey we also make it easy to start" or "hey did you know you use
CDI in OSGi too". I think we should concentrate on more evangelism about
what the real power of OSGi is. And for me that means exactly the opposite
of hiding things.
So I generalized about OSGi and naturally you will probably ask about
Karaf. What made me look at and stay with Karaf for my personal projects
was "features/KARs", "instances" and much friendlier console! I still
prefer Karaf's features over subsystems. I would love to see Karaf going
that way - making it easier to work with things, providing useful
features,
improving user/developer experience, ... but without hiding things and
without trying to convince people that some "magic" would make it up for
the lack of knowledge.
But that's just me. I may be wrong!
Best,
Milen
On Fri, Sep 11, 2015 at 9:09 AM, Achim Nierbeck <[email protected]>
wrote:
Hi,
Fully agree.
You want karaf-boot to be a collections of BoM that you can assembly as
lego brick: I'm with you !
Anything that allow us to provide something easy & straight forward is
good for me !
Let me move forward on karaf-boot and try to create such kind of BoM
there.
yeah ... might want to take a look at those available from spring-boot:
https://github.com/spring-projects/spring-boot/tree/master/spring-boot-starters
and to have an easy assmbly we need the following:
one or more maven-plugin(s) that do the following:
1/ build the bundle
2/ create the requirements
3/ checks the available features in the project (inherited from the BOMs)
4/ include those features in the resulting feature
5/ instead of a feature generate a profile
6/ run a feature/profile based karaf - based on the minimalistic Karaf
7/ most important within one project with a karaf-boot packaging :-)
I think only 3 is actually not as good as it should be right now and
needs
improvement.
But with Karaf4 features it shouldn't be to hard to achieve
The rest is mostly available today we just need make it work together.
regards, Achim
Regards
JB
On 09/11/2015 08:55 AM, Achim Nierbeck wrote:
Hi JB,
my point is that you are a veteran on different technologies, that you
know
;)
and that's the reason I already know where other people are struggling
with.
I do a lot of consulting to people that either don't care or are not
interested in their day-job.
They just need to get that stuff done.
Therefore it needs to be easy as taking a dump.
But anyway, veteran or not, it would be very helpful to have tooling. I
would love to have a karaf-boot tool that allows me to quickly create
my
artifacts, without taking a look on 3 or 4 different
projects/technologies,
plugins, etc/
Just my €0.02 (I'm in € now ;)).
I'm with you that we need better tooling, but actually we should focus
on
the build-chain first.
Make it good, make it awesome.
After that let's take a look on where we find some more room for
improvement.
That's why I think if we talk of *-boot we should focus on having easy
inclusion of different dependencies.
Cause not everybody want's to start with a REST-Microservice, but might
be
interested in Database first.
That's why we need different BOMs that stick together as lego-bricks.
regards, Achim
Regards
JB
On 09/11/2015 08:47 AM, Achim Nierbeck wrote:
Hi JB,
I'm very sorry but I have to completely disagree on this.
Let me point this out inline
Generally speaking, I think we are not the best ones to evaluate this
because we are involved in the "low level", and so we might not see
values
there.
This might be true for core developers that only work on Karaf, it
certainly doesn't affect me, as my day-job requires me to work with
everything else but OSGi. Therefore I think I'm in the very
convenient
position to say: "I know what is missing and I know where the
benefits
of
Spring-Boot are"
Working on Karaf and Pax Web is just a mere hobby for me, as it
doesn't
pay
my bills.
It would be great to have "new developers" feedback (it's where I
started
for karaf-boot actually). That's the key point: think when you are
very
new
to Karaf and you have to start.
see above
Anyway, my comments inline:
On 09/10/2015 11:58 PM, Achim Nierbeck wrote:
Hi
after reading this thread about two times, I finally understood the
intention and the confusion in the thread.
Let me try to summarize this to start some more confusion :-D
Initial Problem:
- learning OSGi has a steep learning curve
- initial setup for a new OSGi project needs a lot of
infrastructural
"thingis"
- doing the "microservice" dance is hard as it requires to much
"extras"
to
have a simple REST service
-- including infrastructure
- Spring boot brings everything needed in one place in one
"application"
with just annotations
These are the "problems" we know of and if I did get it right are
the
intention for the Karaf-Boot project.
Now let me try to summarize the idea on how to solve that.
From a simple Class file with some annotation generate
- a OSGi service, including OSGi wiring via Blueprint - via an
extra
maven
plugin
- get rid of all those infrastructural "add-ons" for the first OSGi
bundle
by having a easy to use Parent-POM
- do the microservice - dance by wrapping everything together
including
CXF
in a "one-size-fits-all" executable jar, which is a
wonna-be-spring-boot
jar but made of karaf
Now some thoughts of mine ...
I somehow fear you try to mix several problems and try to solve all
of
them
with one go.
Let's try to analyze those initial problems separately and we might
find a
valid approach.
Learning curve of OSGi:
right now we have different approaches to make it easier with OSGi.
- Blueprint
- DS
- CDI
- iPojo
- Felix DependencyManager
Blueprint just tastes to much like spring xml and actually isn't
state
of
the art anymore. You'll get a lot of negative feedback regarding
the
"old-school" xml. It's biggest plus is the Enterprise "features"
like
JPA
and JTA, which isn't covered by any other technique right now
(unless
you
look at non Apache Hosted OSS projects like Amdatu).
Declarative Services, especially the latest R6 looks rather
promising,
especially in conjunction with MetaType. But we have specialized
annotations which again don't actually help with the learning
curve.
Another downside is the missing JPA and JTA Enterprise features.
CDI, we have the Pax-CDI project which has been on the way of being
the
reference implementation of the OSGi-CDI spec. Well, we all know
how
that
turned out. One of its biggest benefits is definitely the easy
transition
because of the CDI annotation which help a lot with wiring inside a
bundle
and also with extra annotations (@OsgiService) with OSGi-Services.
CDI
though still lacks runtime OSGi annotation support for JPA and JTA
if
we
are somehow capable to compensate that, we'll have the required EE
stack
at
hand.
iPojo ... sorry never used
Dependency Manager is a bit more low-level compared to DS but seems
to
have
a nice DSL for easy wiring of Services.
So do we really need another Build-Time-Annotation which generates
another
"wiring" plan which is used during runtime (exactly what DS already
does)?
Right now I'm not convinced of this. Instead of another generation
I
would
prefer to use CDI as it is known to work in classic Spring/EE world
and
OSGi. Instead we should focus on bringing the full support of
Enterprise
style annotations to the OSGi world.
I agree. With the current annotations (whatever the ones we use,
CDI,
DS,
etc):
- they are very low level, and doesn't provide "key turn"
annotations
- they don't provide enterprise ready annotations
- depending of the annotations, it's spread on different
dependencies
and
packages (not easy for the user)
Basically, a new developer starts on Karaf, it could be lost: a fair
question is what technology should I use.
Use CDI it's a standard annotation and can equally be used for
Spring
or
in
a modern Enterprise Server.
We bring an important flexibility, which is awesome for the advanced
users.
But this flexibility means it's not easy to start and choose
something: I
have to learn, prepare my pom.xml accordingly, etc.
The purpose of karaf-boot is not to create new technology, it's just
to
leverage the existing ones, hide it to the developer, and provide a
quick
and easy starter.
great, and this is the point we need to focus on! Make it easier to
develop
a Bundle to run on Karaf.
That's why I might need to elaborate a bit more about my idea of
BOMs.
Take for example the spring-boot-log4j-starter bom. If you use that
one
all
is included to work with log4j logging, one dependency in your POM,
no need to have a Parent.
Same for REST, depending on what people would like to use it can be a
karaf-boot-cxf-jaxrs-starter bom, which contains the dependencies for
working with cxf rest including the feature definition that needs to
be
used by karaf.
Here we need something "new", if a feature is present in the POM and
we
have the karaf-maven-plugin in use (the only valid point for a Parent
POM
to have that as default available) this feature must be used inside
the
generated feature as dependency and the karaf-maven-plugin should
generate
according to the requirements the dependencies from that feature.
Initial Setup for a new OSGi Bundle Project
Instead of a parent POM I think it would be much more beneficial to
work
with a BOM (Bill of Material) for easier development, especially
when
working with std. CDI annotations plus some extra PAX-CDI ones.
Maven
Archetype are actually good enough to create an initial structure
for
a
maven project.
The big benefit of the spring-boot approach is to actually have a
bunch
of
different BOMs that can be used to add certain functionalities to
the
project, aka spring-boot-*-starter.
To start a karaf-boot I think we should first try to have a
karaf:run
available as maven plugin.
I already have karaf:run on one of my branches, but the purpose is
different. Let's keep the starter out of the picture for now.
A BoM can be materialize as a parent-pom, it's the purpose of the
karaf-boot-parent.
Maven archetype is good, but it's require to execute the archetype,
update
the project definition before being able to build. Of course, it
makes
sense to provide it.
But, the big advantage of karaf-boot-parent, it's again easy and key
turn:
I'm a new developer, I just inherit from karaf-boot-parent, I just
define
groupId, artifactId, version, I'm ready to go.
I'm sorry but this is a too big cannon you use to shoot on sparrows.
Think minimalistic and modular. With the karaf-boot-*-starter boms we
would
achieve something far more modular and closer to what people actually
need.
And forgive me for comparing it with spring-boot again, the big
benefit
of
it is actually those *starter boms.
The microservice dance
actually it's just add a rest-service on top of a OSGi service,
that's
all
that is needed in Karaf.
Right now I'm not in favor of any certain framework. CXF seems a
bit
bloated but is known to work, but requires blueprint.
Jersey, I've seen that to be working with "plain" OSGi. A bit of
polishing
and it should be quite easy to use, especially with CDI at hand.
But it needs more to dance the microservice dance, you need "small"
containers ... which is quite contrary to the way Karaf and OSGi in
general
is working with services.
But this is the point I think the karaf profiles come in handy. You
don't
need a full blown Karaf, just a basic infrastructure with your own
Bundle,
might as well ignore the shell. In the end dump that into a docker
container and if you need to do a bugfix do it the "docker" - way.
It's another point, but @rest and karaf-boot-starter address this,
using
profiles and karaf minimal distribution.
here we are inline, a minimalistic distribution based on profiles
should
do.
spring-boot brings it all in one go
karaf-boot should do the same, but actually I fear we do more then
needed.
For a new Project setup I'd rather would like to see different
karaf-starter-* BOMs and a karaf:run maven plugin
Some more docuementation for the profiles of Karaf could also be
helpful
:D
to build minimalistic karaf instances runnable in docker
containers.
Regarding the karaf:run it might be interesting to "re-activate"
the
pax:run maven plugin to run nicely with a karaf instance, or use it
as
foundation for the karaf:run maven plugin.
See my previous comment.
So in the end, do we really need all this?
I'm not so sure, but we surely need an easier "to use" approach.
Therefore we should first focus on having easier setup of bundle
development.
-> karaf-boot-starter-* BOMs should take care of that
-> karaf:run should make it easier to have a running container
Do we need new annotations? I can't see that yet.
Instead we should/could focus on the following:
a) make sure DS also is capable to work with JPA/JTA and some other
enterprise annotations
b) make sure CDI works with runtime JPA/JTA annotation smoothly
c) provide more demos and archetypes with OSGi and CDI annotations
You talk about JPA/JTA and I agree. But don't forget high level
annotations like @jpa(provider = "openjpa", dataSource = "my"),
@rest,
@soap, @jms, etc.
all those "high" level annotations are already solve.
Take Jersey or CXF you can use either to solve the @rest or @soap
annotations. We don't need extras here
We should thoroughly look through the ones that are already available
with
CDI and make sure we don't re-invent the wheel wrong here.
That's why abstract, high level annotations could make sense.
only for the ones missing, yes then it might be helpful, but to my
understanding this should be the last Story in the backlog to have a
quick-and-easy to build environment.
regards, Achim
Regards
JB
regards, Achim
2015-09-10 20:41 GMT+02:00 Jean-Baptiste Onofré <[email protected]>:
Thanks Milen,
it's an open place to discussion. We just share standpoints and
opinions:
that's the key part !!!
My goal is to give more traction on Karaf by providing easier
We all provide valid points, but I think we are not the most
setted
to
argue as we are deeply involved in OSGi and Karaf. The karaf-boot
proto
came when discussing with new Karaf users, coming from "outside"
of
OSGi,
or people that decided to use spring-boot (even if they like a lot
Karaf),
just because it's easier. It's hardly frustrating for us as we
just
need
some tooling to provide even more traction. On the container side,
I
think
Karaf is already great, and answers all needs. The part where we
should
improve what we deliver is around developer tooling: easier,
faster,
key
turn.
If karaf-boot will be a success, I don't know (who knows ? ;)).
But
anyway, it brings points, questions, and identify some missings in
the
current picture.
My $0.01 ;)
Regards
JB
On 09/10/2015 08:02 PM, Milen Dyankov wrote:
Well I was just referring to your example but I get your point.
Which
reminds me of EnRoute <http://enroute.osgi.org/> project which
despite
the
big names and the most popular OSGI build tool behind it, doesn't
seem
to
get as much traction as I expected!
That said, I really admire your enthusiasm and wish KarafBoot can
be
more
successful that that. I'm not trying to discourage you! Just it
seams
what
you are after is something that other people have tried already
with
questionable success.
Best,
Milen
On Thu, Sep 10, 2015 at 7:22 PM, Jean-Baptiste Onofré <
[email protected]>
wrote:
And how to you deal with jpa, jta, rest, etc with SCR annotations
?
Regards
JB
On 09/10/2015 07:16 PM, Milen Dyankov wrote:
So correct me if I'm wrong but if I get the sample you provided
in
the
first mail and replace:
- the parent pom with "maven-bundle-plugin"
- @Bean with @Component
- @Init with @Activate
wouldn't that have the exact same end result? I mean it
obviously
differ
in
terms of what gets generated (Blueprint vs DS) but form end
user
perspective there is no difference, right?
On Thu, Sep 10, 2015 at 6:55 PM, Jean-Baptiste Onofré <
[email protected]>
wrote:
Hey Milen,
Actually, there's too part:
1/ karaf-boot-starter will do the ready to start artifact,
embedding
karaf, but it's another point
2/ the value of karaf-boot annotations and plugin is first to
simplify
the
bundle/artifact ready to be deploy-able into Karaf (generate
the
"plumbing"
easily for developers).
Regards
JB
On 09/10/2015 06:50 PM, Milen Dyankov wrote:
" ... that you deploy in Karaf ..."
OK may be I misunderstood the concept. I thought the result is
standalone
executable JAR, thus my comments above. If on the other hand
I
need
to
install Karaf and then deploy my services into it I really
don't
see
how
it
differs form what people are doing now?
I'm sorry if I'm not making much sense. I didn't have the
time
to
experiment with your code and samples so may be I'm missing
an
important
peace here.
Best,
Milen
On Thu, Sep 10, 2015 at 6:27 PM, Jean-Baptiste Onofré <
[email protected]>
wrote:
Allow me to disagree: Karaf is a perfect container for
microservices.
Image to create a microservice (using karaf-boot) that you
deploy
in
Karaf
and use such service in another microservice, all wired with
OSGi
service
and Karaf: we leverage OSGi/Karaf as a microservices
container.
But even without talking of microservices, new developers to
Karaf
(and
OSGi generally speaking) are frustrated by the effort on non
business
code
to do (I have to write an Activator, or a descriptor, etc,
etc).
So, a tooling to simplify this is still a valid addition
IMHO.
Regards
JB
On 09/10/2015 06:23 PM, Milen Dyankov wrote:
I might be wrong but I think the whole success of SpringBoot
(apart
from
having the "Spring" in it) is the microservices hype!
it's quick and easy but most usecases follow the "create one
(or
very
few)
service(s), pack them as single executable and access them
via
REST"
pattern. We can obviously do the same with OSGi and Karaf
in
particular
but
personally I think this makes absolutely no sense. In such
approach
one
in
not benefiting form OSGi almost at all. Honestly speaking I
would
argue
that if one does not understand how OSGi service layer
works
(regardless
of
the framework used to register/access services) it makes no
sense
to
use
OSGi at all.
Just my 2 cents!
Regards,
Milen
On Thu, Sep 10, 2015 at 6:08 PM, Christian Schneider <
[email protected]> wrote:
I already created such a maven plugin in aries. The user
can
use
standard
CDI and JEE annotations and the result is blueprint xml.
How is the new approach different / better?
Why should it be good for the developer to move away from
well
defined
standard annotations and use custom annotations that bind
him
to
karaf?
I mean if this is created by the spring guys I know they
want
to
catch
people by perceived simplicity and then make sure to make
it
difficult
to
switch. As an open source comminity I do not know why we
should
do
something like this.
Abstracting away from frameworks just means you create
another
layer
that
people then also have to learn. There were some cases in
the
past
where
this make sense because the underlying frameworks sucked
(like
JEE
2).
This
is not the case today though I think.
What kind of use case do you have in mind? Every project
starts
small
but
it needs to be able to grow then. You can not start with
custom
annoations
and then tell people to later switch to something else
when
the
project grows. I think it makes more sense to make it
easier
for
people
to
use the standard annoations and use the right
dependencies.
If we simply provide a tooling that makes it easy to start
with
SCR
or
blueprint we provide much more value for people as thery
can
then
grow
without any breaking changes.
Christian
Am 10.09.2015 um 17:46 schrieb Jean-Baptiste Onofré:
Because all these annotations are runtime: here we talk
about
tooling
at
build time.
More over, the purpose is to provide more high level
annotations,
which
abstract actual annotations/frameworks that we can use
under
hood.
The purpose of centralizing all in karaf-boot is to have
a
central
project: the developer just use karaf-boot, it doesn't
really
know
what
technologies are involved behind the scene.
For instance, in spring-boot, they use activemq, jersey,
etc,
but
all
from spring-boot. The developers don't know a rest
service
use
jersey
for
instance, it's completely abstracted.
Again the purpose is to simplify life for developers:
splitting
the
annotations in different projects introduces complexity
(at
least
to
find
the dependencies and core import packages).
If an advanced developer wants to use CDI, SCR, etc, he
can
of
course.
Regards
JB
On 09/10/2015 05:40 PM, Christian Schneider wrote:
I am not really enthusiastic about duplicating
functionality
of
cxf
or
aries. Aries supports a very nice approach for
injections,
jpa
and
jta.
Why should it make sense to recreate that?
Aries blueprint also has annoation support even in two
flavors
(CDI,
custom). How does the new approach interact with this?
Instead I propose we create support for such annotations
in
the
respective projects (where they are missing) and
concentrate
on
karaf
as
a container not an application development framework.
By leveraging the existing frameworks we profit from
their
own
development teams. Whatever we recreate will have to be
developed
by
the
very few resources of the karaf team.
Christian
Am 10.09.2015 um 16:53 schrieb Jean-Baptiste Onofré:
Hi Guillaume,
thanks for your feedback.
I fully agree about providing more high level
annotations
(it's
what I
do with @jpa, @rest, @soap, @jta annotations).
I agree that the current annotations are too low level,
and
blueprint
"oriented". I just move forward a bit with the current
codebase,
just
to illustrate karaf-boot usage in the samples.
But again, you are right, and I will create a new
annotations
set.
One of the purpose of karaf-boot annotations is to
"abstract"
the
actual code/artifact that we generate. So, if now we
generate
blueprint, without changing the karaf-boot annotations,
we
will
be
able to generate something else (why not SCR, etc).
I agree with a BOM, but I think it's interesting to
provide
both:
- providing a ready to use parent pom allows developers
to
create
a
very simple pom.xml where all plugins and dependencies
are
already
defined
- for more advanced devs, they can create their own
pom.xml
starting
from the BOM or archetype.
Thanks again for your feedback !
Regards
JB
On 09/10/2015 04:44 PM, Guillaume Nodet wrote:
I like the idea.
For the annotations, we need to keep really high level.
The
annotations in
the code base right now are much too close to
blueprint.
I think we need to grab a small enough subset so that
the
annotations
--
Jean-Baptiste Onofré
[email protected]
http://blog.nanthrax.net
Talend - http://www.talend.com
