what is api-paste.ini file in openstack - openstack

I've seen api-paste.ini as a conf file after installing openstack.
It looks like substituting some prefixes for python implementation but have no clue about this.
Here, my questions are:
What script is it?
it looks like very bizarre grammar like the following:
[composite:metadata]
use = egg:Paste#urlmap
/: meta
How does it work within python script?

See documentation for Paste Deploy.
The api-paste.ini is the configuration for the above web-services framework. Paste.deploy allows you to separate concerns between writing your application and middleware/filters from the composition of them into a web service. You define you WSGI applications and any middleware filters in the configuration file then you can compose pipelines which include the middleware/filters you want into your web-service, e.g. authentication, rate-limiting, etc.
You want to temporarily remove authentication, take it out of your pipeline and restart your web service.
The declaration above is declaring a composite application, but with only one application binding (a bit unnecessary - normally you would expect to see more than one binding, e.g. for different versions of the application). The WSGI application app:meta will be bound to / and you should have a declaration of app:meta later in the file. The implementation of the composite app is declared via the use and the egg:Paste#urlmap is a simple reference implementation.
You load this in your program with paste.deploy.loadwsgi.loadapp().
There is a proposal/recommendation(?) to move away from Paste Deploy/WebOb to WSME/Pecan see OpenStack Common WSGI

Related

A way to configure WebSphere 8.5 Liberty Profile programmatically?

I'm moving from IBM RAD 8 / WAS 7.0 to IBM RAD 9 / WAS 8.5. Liberty Profile. There's a plenty of configuration things such as URLs and namespace bindings.
I've found an information that WSADMIN is not working for Liberty Profile. I haven't found, however, the information, how to access similar functionality as in wsadmin/jython, for example for creating URLs, namespace bindings, etc.?
How to script such things under WebSphere Liberty Profile?
I'll try to address a few things that are implied by your use of wsadmin. I may be overshooting, but I hope this helps:
WSADMIN applies only to the full WebSphere Application Server. jython scripting for the Liberty profile is possible, though you're basically performing JMX operations on a server. Here is something to get started with: https://www.ibmdw.net/wasdev/docs/creating-remote-jmx-connections-with-jython/
There is no way to reconfigure a Liberty profile server via a JMX operation, however. All server configuration (or reconfiguration) is done by editing the server configuration file (either manually with an editor of your choice, via the eclipse tools, or with a script that modifies your XML).
The Liberty profile does not support CORBA or CORBA namespaces (corbaloc or corbaname), or remote EJBs. Liberty profile servers also are not part of the cell/node topology of full profile servers. Instead, Liberty profile servers form collectives, as described here:
http://pic.dhe.ibm.com/infocenter/wasinfo/v8r5/topic/com.ibm.websphere.wlp.core.doc/ae/cwlp_collective_arch.html
You can add strings to JNDI using the jndiEntry element in your server configuration as described here: http://pic.dhe.ibm.com/infocenter/wasinfo/v8r5/topic/com.ibm.websphere.wlp.core.doc/ae/twlp_dep_jndi.html
Information about configuring datasources (I am guessing at what you might need URLs and namespace bindings for) is here (see also the subtopics): http://pic.dhe.ibm.com/infocenter/wasinfo/v8r5/topic/com.ibm.websphere.wlp.core.doc/ae/twlp_dep_configuring_ds.html.
The easiest way is to edit the XML directly or using a script in the language of your choice. The idea is that the config is simple enough wsadmin is no longer needed - it's intended to be human readable and human maintainable. You can import XML snippets if you have repeated config elements you want to share similar elements across multiple servers, or create the same config elements multiple times.

Calling a web/wcf service from orchestration: adding a generated item vs adding service reference

If I want to call a web service or wcf method from an orchestration, I can do it by either adding a service reference to the project or adding a generated item. What is the advantage of either approach - is there a best practice?
Steef -Jan Wiggers answers a similar question here
TL;DR - Always use the Generated Items wizard.
My 10c - Although the .xsd files imported by Add Service is added as a schema and set to BtsCompile, there are some limitations such as:
Add Service Reference will add the client proxy, which isn't needed in a BizTalk project (and which might 'tempt' your devs to do silly things like using this proxy from a Custom assembly)
Service Reference makes a mess of importing complicated WSDL (e.g. with Generics or dependencies on other Schemas), See Considerations when consuming Web Services
Using the Add Generated Items wizard does extra work for you:
Adds in a Port Type for accessing the service, already preconfigured for the correct message types. Note however that it adds the Port type to a dummy .odx - i.e. don't delete the odx until you've moved the Port type elsewhere.
Allow you to create the Send Port bindings at the same time.
One thing I would recommend with the Wizard, is to create a folder for the WCF reference and always import all the artifacts into the folder (i.e. don't do the usual separation of Schemas from Ports and leave the dummy .odx there as well). This way, if you need to regenerate the items, just delete everything in the folder and start again (sadly, the wizard doesn't have a Update Service Reference equivalent.
Also note that if you do move the generated Schemas and Port Types into a separate assembly, that you will need to change the type modifier access to Public (it is internal by default)

how to deploy flex app using different web service urls?

Is there some sort of configuration settings in FlashBuilder 4.5 where you can easily switch between webservice urls? Right now I have to delete and recreate the web service every time I switch from local to production and vice versa.
The need/requirement is this – Since I work in a startup, we keep changing servers, and their IP addresses. And being a service oriented application – I need to be able to edit the webservice endpoints in my Flex application in a easy manner every time this happens.
My Solution for this -
Assumption is that my webservice endpoint looks like this -
http:////ListAllServices/
1) Create a file config.xml in a folder named “settings” that sits in the root folder of your Flex application – outside the “src” folder. And the config.xml will be a simple xml file of the following format -
localhostTestFlexApp
At the end of this exercise the directory structure of your flex source code will look like this -
flex_src(root of the source code)
-com(some source folder)
–testapp
—view
—
-images
-settings
–config.xml
-appName.mxml
2) Now in your application code, setup a HTTPService object either in mxml or action script. Set the url of that object to this value- “settings/config.xml” – And the above xml fiel containing the current settings will be loaded into memory .
Now you can store these values in a singleton object and construct your Webservice call at runtime.
And whenever you want to move this to a new server in production, edit the tag of your config.xml and you should be good to go.
And this can be automated as well via the EnvGen ant task.
This is not the best way but yes it is very helpful while switching among servers.
Alrighty... The way I was doing it before in fact worked. The problem was browser caching.
For the benefit of others I modified the subsclass for the generated service and replace the wsdl variable with whatever endpoint I need.

Using web services in different environments

We have a series of web services that live in different environments (dev/qa/staging/production) that are accessed from a web application, a web site, and other services. There are a few different service areas as well. So for production, we have services on four different boxes.
We conquered the db connection string issue by checking the hostname in global.asax and setting some application wide settings based on that hostname. There is a config.xml that is in source control that list the various hostnames and what settings they should get.
However, we haven't found an elegant solution for web services. What we have done so far is add references to all the environments to the projects and add several using statements to the files that use the services. When we checkout the project, we uncomment the appropriate using statement for the environment we're in.
It looks something like this:
// Development
// using com.tracking-services.dev
// using com.upload-services.dev
// QA
// using com.tracking-services.qa
// using com.upload-services.qa
// Production
// using com.tracking-services.www
// using com.upload-services.www
Obviously as we use web services more and more this technique will get more and more burdensome.
I have considered putting the namespaces into web.config.dev, web.config.qa, etc and swapping them out on application start in global.asax. I don't think that will work because by the time global.asax is run the compilation is already done and the web.config changes won't have much effect.
Since the "best practices" include using web services for data access, I'm hoping this is not a unique problem and someone has already come up with a solution.
Or are we going about this whole thing wrong?
Edit:
These are asmx web services. There is no url referenced in the web.config that I can find.
Make one reference and use configuration to switch the target urls as appropriate. No reason to have separate proxies at all.

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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