Who resolves properties in akka config files? - sbt

I have project with SBT and akka. There is a akka config file:
akka {
loglevel = ${?LOG_LEVEL}
}
I understand that ${? refers to read property from System properties but who is responsitive for that? It is SBT or akka feature? Also how does it names? I do not understand what to search about how does this mechanism works - the "property resolving" search request for sbt and akka return so many resources without such pretty `{${?}' syntax.

Actually this is typesafe config.

Related

How to get config file for Cordapp?

How to get config file for Cordapp in Java like in sample?
serviceHub.getAppContext().config
After getAppContext() i can't find anything about config file.
This feature is not available in Corda 3. As of this answer, it is only part of the unstable master branch. It will be included in a future release of Corda.
However, you can implement this manually for now as follows: How to provide a CorDapp with custom config in Corda?.

Editing configuration files in Pax Exam

I am using Pax Exam to perform integration tests to my OSGi application. I have a configuration factory in which I specify the Karaf feature of my application to be installed in the test container and then modify some of a proerty of a .cfg file installed as part of my feature.
public class TestConfigurationFactory implements ConfigurationFactory {
#Override
public Option[] createConfiguration() {
return options(
karafDistributionConfiguration()
.frameworkUrl(
maven().groupId("org.apache.karaf")
.artifactId("apache-karaf")
.version("3.0.1").type("tar.gz"))
.unpackDirectory(new File("target/exam"))
.useDeployFolder(false),
keepRuntimeFolder(),
// Karaf (own) features.
KarafDistributionOption.features(
maven().groupId("org.apache.karaf.features")
.artifactId("standard").classifier("features")
.version("3.0.1").type("xml"), "scr"),
// CXF features.
KarafDistributionOption.features(maven()
.groupId("org.apache.cxf.karaf")
.artifactId("apache-cxf").version("2.7.9")
.classifier("features").type("xml")),
// Application features.
KarafDistributionOption.features(
maven().groupId("com.me.project")
.artifactId("my-karaf-features")
.version("1.0.0-SNAPSHOT")
.classifier("features").type("xml"), "my-feature"),
KarafDistributionOption.editConfigurationFilePut(
"etc/com.me.test.cfg", "key", "value"));
}
}
The property I specify in editConfigurationFilePut is modified correctly, however the rest of the .cfg file's properties are deleted. If I use the editConfigurationFilePut method to edit one of Karaf's configuration files it works as expected (just adds the new property without modifying the existing ones) so I am thinking that perhaps the problem is that Pax Exam attempts to modify the configuration before the .cfg file is installed by my feature and therefore creates a new file to put the property in. If this is the case is there some way to synchronise this process so that the .cfg file is edited only after the feature is properly installed?
There are a two different reasons for this.
1) The feature does get installed after the configfile has been "edited"
2) The feature only contains a config section and not a configfile section
I'd guess reason one is the most likely cause of this since it needs a running Karaf to install a feature through Pax Exam. So to work around reason one, replace the config with a config file present in your test project.
For reason two, make sure the feature actually does reference a config instead of a configuration admin config, or add your config to the configuration of the config-admin service. You can achieve this by injecting the ConfigAdmin service in your unit test and add your properties to the configuration pid.
EDIT:
Combine both solutions
Since because of 1) it takes longer for the config-file to be actually available, let config-admin service do the rest.
Make sure your test does retrieve the config-admin service either by injecting it or by waiting for it's availability.
Now within a #Before method make sure you wait till your config is complete and change it from there on. This way you don't need to duplicate the config files.

Typesafe Console not connecting to app

I am trying to use the typesafe console on an application that I have. Bear with the explanation, but it is important to get the context
My application is a web application. It has a maven dependency on a jar that uses akka (in other words, the web app doesn't interact akka directly, the akka stuff is transparent to the web app).
I have downloaded typesafe-console developer 1.3.1.
I added the load time weaver to the jvm arguments, my startup arguments look like:
-javaagent:/opt/typesafe-console-developer-1.3.1/lib/weaver/aspectjweaver.jar
-Dorg.aspectj.tracing.factory=default
-Djava.library.path=/opt/typesafe-console-developer-1.3.1/lib/sigar
-Daj.weaving.verbose=true
I do get some weaving output, and it does indicate that it is using the aop.xml in the trace-akka jars.
My application starts up just fine in tomcat, everything runs dandily.
However, when I go to the typesafe console, I don't see anything there.
I did create an application.conf file in my web application like so:
akka {
loggers = ["com.typesafe.atmos.trace.Slf4jTraceContextLogger"]
loglevel = "INFO"
}
atmos {
trace {
enabled = true
traceable {
"*" = on
}
sampling {
"*" = 1
}
}}
My guess is that I missed a step someplace, or perhaps the application config file is not getting picked up?
Any help is greatly appreciated!
It was the application config file was not being loaded.
I just had a little hack to override the application config file for akka and it worked!

Unity 2.0 XML configuration possible?

Is it possible to use custom XML to store unity container configuration in my IoC class library project?
I dont want to store the IoC config at the startup project (WPF project).
Regards
Bryan
You can use ConfigurationManager.OpenMappedExeConfiguration to load an arbitrary file, but you'll need to do that yourself - the simpler overloads will go to the appdomain's config file by default.
If you have the Unity source code, you can look in the Unity\Tests\TestSupport.Unity\Configuration\ConfigFileLoader.cs file for an (perhap overly complex) example. There we pull a config file out of a resource, dump it to disk, and then load it via ConfigurationManager.

How to configure WCF in a separate dll project

I'm developing a web application (ASP.NET 3.5) that will consume a number of web services. I have created a separate dll-project for each web service: these projects contains the service reference and client code.
However, the calling website MUST have the <system.serviceModel> information (the <bindings> and <client> nodes) in it's web.config, even though this information is also in the dll's app.config file! I have tried copying the serviceclass.dll.config over to the bin directory of the website, but this didn't help.
Is there any way to centralize the configuration of a WCF client?
I've only limited WCF experience, all with BasicHTTP bindings. But I'm allergic to WCF's xml files and have managed to avoid them thus far. I don't recomend this generally but I put the configuration details in my apps existing configuration store and then apply them programatically. E.g. With a Web service proxy I use the constructor for the Client that takes 'bindings'and 'endpoint' and programatically apply the settings to the bindings & endpoint.
A more elegent solution appears to be descibed here: Reading WCF Configuration from a Custom Location, but I haven't tried it yet.
From my experience, library projects never read app.config.
So you can really delete the file because it is not used. The library's host configuration is read instead, so that is the only place the endpoint and binding configuration should be.
It's possible to forgo xml config and build up the Binding and Endpoint classes associated with the service in the constructor or a custom "Service Factory". iDesign has some good information on this:
http://www.idesign.net/idesign/DesktopDefault.aspx?tabindex=5&tabid=11
(See In Proc Factory)
In their approach, you set attributes on your services to specify at a high level how they should work (ie [Internet], [Intranet], [BusinessToBusiness]), and the service factory configures the service according to best practices for each scenario. Their book describes building this sort of service:
http://www.amazon.com/Programming-WCF-Services-Juval-Lowy/dp/0596526997
If you just want to share configuration XML config, maybe use the configSource attribute to specify a path for configuration: http://weblogs.asp.net/cibrax/archive/2007/07/24/configsource-attribute-on-system-servicemodel-section.aspx
Remember that a configuration file is is read by an executable that has an entry point. A library dll does not have an entry point so it is not the assembly that will read it. The executing assembly must have a configuration file to read.
If you would like to centralize your web configs then I would suggest you look into nesting them in IIS with virtual directories. This will allow you to use the configuration inheritance to centralize whatever you need.
There are 2 options.
Option 1. Working with channels.
If you are working with channels directly, .NET 4.0 and .NET 4.5 has the ConfigurationChannelFactory. The example on MSDN looks like this:
ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap();
fileMap.ExeConfigFilename = "Test.config";
Configuration newConfiguration = ConfigurationManager.OpenMappedExeConfiguration(
fileMap,
ConfigurationUserLevel.None);
ConfigurationChannelFactory<ICalculatorChannel> factory1 =
new ConfigurationChannelFactory<ICalculatorChannel>(
"endpoint1",
newConfiguration,
new EndpointAddress("http://localhost:8000/servicemodelsamples/service"));
ICalculatorChannel client1 = factory1.CreateChannel();
As pointed out by Langdon, you can use the endpoint address from the configuration file by simply passing in null, like this:
var factory1 = new ConfigurationChannelFactory<ICalculatorChannel>(
"endpoint1",
newConfiguration,
null);
ICalculatorChannel client1 = factory1.CreateChannel();
This is discussed in the MSDN documentation.
Option 2. Working with proxies.
If you're working with code-generated proxies, you can read the config file and load a ServiceModelSectionGroup. There is a bit more work involved than simply using the ConfigurationChannelFactory but at least you can continue using the generated proxy (that under the hood uses a ChannelFactory and manages the IChannelFactory for you.
Pablo Cibraro shows a nice example of this here: Getting WCF Bindings and Behaviors from any config source
First of all class libraries (DLLs) do not have their own configuration, however they can read the configuration of their host (Web/Executable etc.). That being said, I still maintain an app.config file on the library projects as a template and easy reference.
As far as the service configuration itself is concerned, WCF configuration can make somebody easily pull their hair out. It is an over-engineered over-complicated piece. The goal of your applications should be to depend least on the configuration, while maintaining flexibility of deployment scenarios your product is going to come across.

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