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From Dario Amiri <dariusham...@hotmail.com>
Subject Re: Levels of Containerization - focus on Docker and Karaf
Date Fri, 13 Jan 2017 22:04:14 GMT
I'm aware of this workaround. IIRC, you still need to include an additional Java system property
in your invocation of karaf. It's a viable workaround but not the best situation.

On 01/13/2017 01:17 PM, Elliot Metsger wrote:
We found we were able to use a formulation of property values that allowed for sensible defaults
overridden by environment variables (e.g. [1]):

fcrepo.baseURI = ${env:FCREPO_BASEURI:-<http://localhost:8080/fcrepo/rest>http://localhost:8080/fcrepo/rest}
fcrepo.proxyURI = ${env:FCREPO_PROXYURI:-<http://localhost:8080/fcrepo>http://localhost:8080/fcrepo}
apix.host = ${env:APIX_HOST:-localhost}
apix.port = ${env:APIX_PORT:-80}
apix.interceptPath = ${env:APIX_INTERCEPT_PATH:-fcrepo/rest}
apix.proxyPath = ${env:APIX_PROXY_PATH:-fcrepo}

[1] https://github.com/fcrepo4-labs/fcrepo-api-x-demo/blob/master/apix/0.1.0/cfg/org.fcrepo.apix.routing.cfg

On Fri, Jan 13, 2017 at 4:13 PM, Nick Baker <nbaker@pentaho.com<mailto:nbaker@pentaho.com>>
Injecting configuration into a containerized app (docker) is considered standard practice.
The friction here is the level of sophistication in OSGI Configuration.

It seems to me what you need isn't some hack to push configurations through environment variables,
but a new implementation of ConfigurationAdmin, or an agent which interacts with CM mirroring
configurations in from an external system.

In our usage it's common to have a "tenant", think Walmart vs Target. Setting the tenant ID
as an environment variable then having the configurations loaded from Zookeeper or whatever,
injected into CM seems right.

From: Dario Amiri <<mailto:dariushamiri@hotmail.com>dariushamiri@hotmail.com<mailto:dariushamiri@hotmail.com>>
Sent: Friday, January 13, 2017 3:21:17 PM

To: user@karaf.apache.org<mailto:user@karaf.apache.org>
Subject: Re: Levels of Containerization - focus on Docker and Karaf

Let me expand on why this is desirable. Without the ability to set configuration through environment
variables, I essentially have to create a docker image for each deployment. I have a root
Dockerfile which assembles the main Karaf container image and brings in dependencies such
as the JRE, then I have a Dockerfile for each deployment environment which builds on top of
the root image by overriding deployment specific configuration. Automation reduces this burden
but it is not ideal.

If I could set the contents of a config file in an environment variable, I could just pass
the configuration directly to my root karaf docker image without having to build on top of

Being able to start Karaf as "java -jar karaf.jar" is desirable because it makes it easier
to use a Karaf based application with PaaS such as Heroku and Cloud Foundry.


On 01/13/2017 12:10 PM, Dario Amiri wrote:

Ideally, I want to be able to do:

java -jar my-karaf.jar

And I can override individual configuration files using some environment variable convention.


On 01/13/2017 11:56 AM, Brad Johnson wrote:
Does it have to be an executable jar file or just a standalone executable? The static profiles
actually create and zip up a full Karaf/felix/dependency/application implementation that when
unzipped has all the standard bin directory items.


From: Dario Amiri [mailto:dariushamiri@hotmail.com]
Sent: Friday, January 13, 2017 1:28 PM
To: user@karaf.apache.org<mailto:user@karaf.apache.org>
Subject: Re: Levels of Containerization - focus on Docker and Karaf

I use Docker and Karaf. I've never had a problem creating a Docker image of my Karaf container.
What I gain is freedom from having to worry about dependency related issues such as whether
the right JRE is available.

That being said there are some challenges when using Karaf to build 12-factor apps. FWIW here's
my two item list of what would make Karaf a more attractive platform from a 12-factor app

1. The ability to inject Karaf configuration through the environment (e.g. environment variables).
Not just a single property, but an entire config admin managed configuration file if necessary.
Even the existing support for reading property values from the environment is cumbersome because
it requires having to setup that relationship as a Java system property as well.

2. The ability to package Karaf as a standalone runnable jar. Looks like Karaf boot is addressing
this. I hope it comes with tooling that makes it easy to transition to this kind of model.


On 01/12/2017 04:44 AM, Nick Baker wrote:

Thanks Guillaume!

This is perfect for our microservice/containerized Karaf. I'll give this a try and see if
we can get our features in startup. We've had issues in the past here.

-Nick Baker

From: Guillaume Nodet <gnodet@apache.org><mailto:gnodet@apache.org>
Sent: Thursday, January 12, 2017 5:55:24 AM
To: user
Subject: Re: Levels of Containerization - focus on Docker and Karaf

Fwiw, starting with Karaf 4.x, you can build custom distributions which are mostly static,
and that more closely map to micro-services / docker images.  The "static" images are called
this way because you they kinda remove all the OSGi dynamism, i.e. no feature service, no
deploy folder, read-only config admin, all bundles being installed at startup time from etc/startup.properties.
This can be easily done by using the karaf maven plugin and configuring startupFeatures and
referencing the static kar, as shown in:
  <https://github.com/apache/karaf/blob/master/demos/profiles/static/pom.xml> https://github.com/apache/karaf/blob/master/demos/profiles/static/pom.xml

2017-01-11 21:07 GMT+01:00 CodeCola <<mailto:prasenjit@rogers.com>prasenjit@rogers.com<mailto:prasenjit@rogers.com>>:
Not a question but a request for comments. With a focus on Java.

Container technology has traditionally been messy with dependencies and no
easy failsafe way until Docker came along to really pack ALL dependencies
(including the JVM) together in one ready-to-ship image that was faster,
more comfortable, and easier to understand than other container and code
shipping methods out there. The spectrum from (Classical) Java EE Containers
(e.g. Tomcat, Jetty) --> Java Application Servers that are containerized
(Karaf, Wildfly, etc), Application Delivery Containers (Docker) and
Virtualization (VMWare, Hyper-V) etc. offers a different level of isolation
with different goals (abstraction, isolation and delivery).

What are the choices, how should they play together, should they be used in
conjunction with each other as they offer different kinds of


View this message in context: <http://karaf.922171.n3.nabble.com/Levels-of-Containerization-focus-on-Docker-and-Karaf-tp4049162.html>
Sent from the Karaf - User mailing list archive at Nabble.com.

Guillaume Nodet
Red Hat, Open Source Integration

Email: <mailto:gnodet@redhat.com> gnodet@redhat.com<mailto:gnodet@redhat.com>
Web: http://fusesource.com<http://fusesource.com/>
Blog: <http://gnodet.blogspot.com/> http://gnodet.blogspot.com/

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