Starting from features, you can create a full static custom
distribution, not actually really using features but startup bundles.
Regards
JB
On 04/18/2016 05:47 PM, Brad Johnson wrote:
I don't know if it is a big deal but here's an example of a current
project I work on. In a static environment much of that could be
generated I'd think. At least the parts that are straight bundles. And
really, in a static include the feature tags themselves could be pulled
in and expanded to bundle statements as well since in the end we aren't
leveraging features from an installed karaf anymore. Those
features/profiles would act more like recipes for the creation of the
karaf-boot itself.
If one went with a convention over configuration approach as well then
one could always specify a configuration.cfg in the root of the
resources directory and have that automatically converted into a cfg
file in the bundle that matched the PID. The whole configfile section
could be eliminated then. If a configuration.cfg file is found in the
resource directory then the static compilation could turn that into the
correct PID.cfg and install it during bundle creation into the etc
directory for boot up.
None of that is huge deal but it would make life a bit more convenient
and since one is now working from a static point of view it seems it
would be much easier to accomplish.
<?xml version="1.0" encoding="UTF-8"?>
<features name="${project.artifactId}-${project.version}"
xmlns="http://karaf.apache.org/xmlns/features/v1.0.0";
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
xsi:schemaLocation="http://karaf.apache.org/xmlns/features/v1.0.0
http://karaf.apache.org/xmlns/features/v1.0.0";>
<!-- The repositories of the Middleware -->
<repository>mvn:org.apache.camel.karaf/apache-camel/${camel-version}/xml/features</repository>
<repository>mvn:org.apache.cxf.karaf/apache-cxf/${cxf-version}/xml/features</repository>
<feature name="payment-hub-gateway-prerequisites"
version="${project.version}">
<configfile finalname="/etc/com.foo.orchestration.cfg"
override="false">mvn:com.foo/orchestration/${project.version}/cfg/configuration</configfile>
<configfile finalname="/etc/com.foo.connector.litle.cfg"
override="false">mvn:com.foo/connector.litle/${project.version}/cfg/configuration</configfile>
<configfile finalname="/etc/com.foo.gateway.cfg"
override="false">mvn:com.foo/gateway/${project.version}/cfg/configuration</configfile>
<configfile finalname="/etc/com.foo.batch.cfg"
override="false">mvn:com.foo/batch/${project.version}/cfg/configuration</configfile>
<configfile finalname="/etc/com.foo.bar.cfg"
override="false">mvn:com.foo/bar/${project.version}/cfg/configuration</configfile>
<configfile finalname="/etc/com.foo.services.cfg"
override="false">mvn:com.foo/services/${project.version}/cfg/configuration</configfile>
<feature>camel-core</feature>
<feature>camel-blueprint</feature>
<feature>camel-cxf</feature>
<feature>camel-jackson</feature>
<feature>camel-xmljson</feature>
<feature>camel-beanio</feature>
<feature>camel-xstream</feature>
<feature>camel-dozer</feature>
<feature>camel-velocity</feature>
<feature>cxf-ws-security</feature>
<bundle>mvn:org.apache.aries.blueprint/org.apache.aries.blueprint.core.compatibility/1.0.0</bundle>
<bundle>mvn:org.codehaus.jettison/jettison/${jettison-version}</bundle>
<bundle>mvn:org.apache.commons/commons-lang3/${commons-lang3-version}</bundle>
<bundle>wrap:mvn:org.apache.httpcomponents/httpcore/${httpcore-version}</bundle>
<bundle>wrap:mvn:org.apache.httpcomponents/httpclient/${httpclient-version}</bundle>
<bundle>wrap:mvn:commons-io/commons-io/${commons-io-version}</bundle>
</feature>
<feature name="foo-hub-gateway" version="${project.version}">
<bundle>mvn:com.foo/models/${project.version}</bundle>
etc. etc.
On Mon, Apr 18, 2016 at 2:29 AM, Christian Schneider
<[email protected] <mailto:[email protected]>> wrote:
I am not very familiar with the concept of profiles till now.
Guillaume explained it a bit to me but honestly I hope we do not
need it too often. An OSGi application should be mainly built out of
bundles and profiles concentrate more on the non OSGi static files
in karaf.
The main part of the packaging in karaf boot is to resolve features
at build time. It uses the static profile but nothing else from the
profiles concept. This part already works. I have created such a
packaging for the tasklist-ds example:
https://github.com/cschneider/Karaf-Tutorial/tree/master/tasklist-ds/app
The second part. The karaf boot development model is still in the
making but you can already use the packaging if you want.
About features and poms you are right. You have to maintain two sets
of dependencies but this is just a result of the fact that OSGi
resolves differently from maven. So this never will completely go
away. What we could do with a pom is create an obr repository. This
could then be used to back a feature repo. So currently in a feature
we have to list all the bundles, with a backing obr repo we could
instead only list some requirements (like top level bundles) and
resolve the rest.
I have prototyped such a packaging using bndtools as it already has
the OBR resolving:
https://github.com/cschneider/bndtools-tutorials/tree/master/tasklist-ds
The creation of the repository went quite smoothly as eclipse m2e
provides nice tooling to define the pom and the necessary excludes.
Defining the requirements in bndtools also works really nicely as
they got a good UI for it.
Unfortunately bndtools does not know about features. So while this
approach is better than defining each single bundle of an
application it is not really better than the karaf approach were you
define most of your deps as features. So this would only be really
useable once we have both features and a backing obr repo.
Another thing that I found bndtools is lacking is all the
preparation karaf already has for some of the more complicated
features like tansactions and cxf. There it is not enough to just
install bundles.
You also have to fiddle with the boot path for transactions and some
java se spec nightmares in the case of cxf. So these are the regions
where karaf really helps.
Christian
On 18.04.2016 07:24, Brad Johnson wrote:
Christian,
I just re-read your section on the static profiles. That makes
sense. I could see this becoming like puppet/chef sort of
recipes or even like the way Docker allows building up of
images. Not that I know those that well. I use features all
the time of course but see huge advantage to making that a
bundle time set of static steps instead of the current runtime
usage. Not that the current use is bad, mind you, its context
is different and slimming down the karaf core by eliminating
that management overhead would be good for something like
karaf-boot. In the current monolithic enterprise environment it
makes sense to have stacks of features available to load when
necessary. The static mechanism would get rid of that. But it
would also permit building up a centralized registry or library
of features that one could leverage by adding into a boot recipe
of some sort. Maybe we'd get the quick flexibility for
creating projects that archetypes always seemed to promise but
never quit seemed to manage.
One item that has always bothered me about features is they are
orthogonal to but replicate much of what goes into a POM. One
ends up with two sets of dependency management mechanisms that
have never really dovetailed. It would be nice if we had a
Maven plugin that could look at the dependencies in a POM and
create a static feature profile or at least give a good guess at
what they should be while allowing for some tweaking. Perhaps
since the karaf-boot environment is static and doesn't rely on
or expect another environment to provide dependencies that would
be easier to accomplish.
Funny how Moore's law took a sideways turn on us. Now we don't
have the ever increasing clock speed but we have cores coming
out our ears and RAM and disk space in abundance. A little
fatness in our deployments is an acceptable trade off now.
Brad
--
Christian Schneider
http://www.liquid-reality.de
Open Source Architect
http://www.talend.com
--
Jean-Baptiste Onofré
[email protected]
http://blog.nanthrax.net
Talend - http://www.talend.com
