What happens when I deploy a .NET web application?

Question

I changed jobs this year, so due to that i switched from Java to C#.In both jobs I work/worked on a large application that is deployed to a server and exposes various webservices.

With the Java job, an ant build process created a .ear file that contained a .war file and other objects. This .ear file was deployed by copying it into a directory within a JBoss/tomcat server. I understood the process fairly well.

With the C# job, I press a green triangle "play" button in Visual Studio and the application is compiled and somehow deployed to IIS, and Visual Studio then starts up a web browser pointing to the application's URL. I don't completely understand what is happening under the hood during this process. We have a build server that creates production builds that go out to production servers, but I don't understand a) what artifacts are produced by the build process, and b) how are those build artifacts deployed to IIS.

I would like to understand the process well enough to manually drive builds and deployments, re-automate the process, and also troubleshoot and modify our existing build and deploy process. I can drive a build with msbuild, but what does that produce, and how would I get it deployed onto another machine's IIS installation?

Answer 1

Just add a note.

So,

If you are working with ASP.NET Website, it should enough to manually copy it to publish folder

If you are working with ASP.NET Web Application, so before publish it should be compiled. All compile operations is performed by MSBuild - command line utility to buld .net projects. But how MSBuild can understand, what it should build and in what way? Easy - there special files with instructions for MSBuild - is solution files (example howto build project from command line "C:\...\MSBuild.exe" /maxcpucount:10 MyAwesomeSolution.sln). Solution file contains references to project files (and build order for projects, etc), project files contains references to files, which included in project (and type of project - library/console/web app/etc, and framework version, and action for each file - build/content/resource, etc). If some file does not included to project, it will be ignored.

So, when you press green button, firstly VS will run MSBuild to build your solution. Inside solution should be written, which project will be used as starting point and what should be done before/after build. Inside project there information, howto debug project (via IIS, IIS express or smthg else).

So, when we working with some CI server, to compile our solution is enough to run MSBuild on CI server with path to solution. Ofcource, to publish compiled solution via CI, additional scripts should be written (to cpy files, etc).

Also, if you want to publish you website to some location, you can create "publish profile". It allows you to publis your website to IIS, FTP, etc, but you have to press "publish" button manually (right click on web project => publish)

Answer 2

What happens when you hit Run (the green triangle) is probably not the best example, because it is using a specialized form of IIS (sometimes called Cassini) hosted within Visual Studio with a debugger attached.

To get a clearer picture of what happens when deploying, use the Publish tool to deploy to a folder on your desktop. In that folder you will see what is essentially the web root. Your project, minus any code files, and a bin directory with the compiled binaries.

Typically only static files such as html, css, and png, etc. will be deployed, while any code files won't. By default Visual Studio "knows" which files to build into the binary, and which to simply copy to the output folder (and which to ignore). But you can change this in cases where you need to override that behavior, or you have a file type VS doesn't know about. In your solution explorer, right click on a file, select properties. In the properties window for that file you'll see "build action", which shows what VS will do with that file.

Hope that helps.