How to deploy a DLL that is constantly changing? - c#

I have created several small applications that use my own DLL. The problem is, this DLL is constantly changing. My current solution to this problem is that I have a Setup project in the class library solution that creates and registers the DLL. In all my applications I then have to open the solution and re-reference the newly created/registered DLL. Then I have to re-compile their setup projects, uninstall the old applications, and then re-install the new application.
There has to be a better way and I'm just not sure because I'm fairly new to all this. I have looked into ClickOnce but I don't think that will solve my issue as I cannot publish a class library. I have looked into checking version numbers but I must be doing something wrong because it doesn't work either.
I understand that once a DLL is created and being used in an application it should essentially not be touched. I do not have that option in this situation. It is constantly updated. Done.
So, is there a better way? A point in the direction of a guide or related question/answer/forum would be greatly appreciated.
Edit: The DLL is not constantly changing during runtime but it is constantly evolving to allow more functionality and detail within the other applications. Also, one big thing I guess I should have mentioned is the Public interface is constantly chaning - usually adding new methods.

Make sure the references to your DLL specify SpecificVersion=false. Then just deploy each new version into the GAC and that should do the trick.
Eventually, you can also manually force versions using Binding Redirection.

A solution you can try is to use a single solution for your project and reference the project wherever it needs to go.

Check out NuGet
You could set up an internal Nuget repository (really just a folder that stores nupkg files.) Then when you build a new DLL, you can update the apps as needed in studio. This would ensure it had the latest version. They shouldn't need a redployment unless there are bugs in the DLL that you're fixing.

One solution is as follows:
Physically separate the interface from the implementation. e.g. AssemblyA is the interface, the application (AssemblyB say) knows only the interface at compile time. The implementation (AssemblyC) also knows/references AssemblyA of course. The point being that AssemblyB does not reference AssemblyC. This will require you to use an IoC container (like MS Unity 2.0 but there are many others) in order to resolve and instantiate your concretes at runtime.
Write an update process that finds the new AssemblyC.dll, replaces the local copy and uses reflection along with the IoCContainer to 'load' the new implementation at what ever interval you require, typically app start up.
The above relies on your interface being stable. If it isn't, you may be able to write a (more) stable Facade.

Related

.NET custom dependencies (no nuget)

So, I'm having trouble adding a git project to my net Core solution, and after spending hours trying to figure this out and being uncapable of finding a solution online, I decided to ask here.
I have a forked github repo (link) in which I modified some files to suit my needs, but I simply can't seem to get it to work with my current project.
The problem I'm having is that normally, when I want a package for a .NET project, I usually simply go to nuget and fetch the necessary dependencies. This is usually very simple and straight forward. But now that I have these modified files, I'm unsure on how to proceed.
I have tried adding it as a submodule, but after I built the project, I got an exception saying that the dll could not be found.
Then I've tried adding the dll itself as a reference, but the ImGui.dll depends on a C dll which couldn't be found then (nor added to the project).
Finally, I've tried adding the csproj as a project of my solution, but that didn't work either
Do you know what am I doing wrong here? Am I missing a key piece or is it just something obvious I'm not seeing? It can't be this hard to get it to work
From the look of it, that repository produces a DLL (output type Class Library). So modify it to your liking, and use the sample program build (ImGui.NET.SampleProgram) to test your changes. Once you're happy, build the DLL project (ImGui.NET) and use the resulting DLL as a Reference in your own app.
In Visual Studio:
Solution Explorer>YourApp>References>Right Click>Add Reference...>Locate your DLL
This means you should also keep track of your modifications to the ImGui.NET project itself, since you may/will be required to maintain this in the future.
Hope this gets you started -- update your question with more specific issues once you're underway.
Edit:
Like #CoolBots mentions, I probably misread your question. Seems like the build depends on cimgui.dll, which you can hotlink from the ImGui repo along with your custom DLL. In fact, the demo app is using cimgui.dll, cimgui.dylib and cimgui.so. Regardless of linking method, you want the files to copy into your build folder. I don't believe subfolder /bin is necessary.
You can find all the cimgui dependencies for various operating systems in the ~/ImGui.NET/deps/cimgui folder.
The demo also utilizes NuGet packages Velrid and Velrid.StartupUtilities.
Depending on your own codebase, you may or may not require these NuGet packages along with the aforementioned class library.

Why are some nuget package references required by applications?

I have a question that has been bothering me for awhile. I ran across this problem a few years back when I was dealing with writing a generic logging wrapper around some hosted provider instances using log4net.
The idea was simple enough, I wanted to write a logging and metrics that hid all the implementation in a separate visual studio project so when you wanted to add any telemetry support to another application you could just include the project, new up an instance of the logger and start logging using generic calls. If you ever switched providers or tweak logging settings, it wouldn't require any changes to the host applications.
This creates a strong decoupling point, where the main application used an interface in a logging class library, but would know nothing about the packages or providers that the logging class library was using to do the real work.
When I did this and tried out using Loggly's nuget package and log4net, I found that the calling application had to have a ref to the nuget package or else the dependent assembly would not be copied to the build directory. At the time I just wrote this off as something odd that they Loggly engineers were doing. But I have since encountered the same behavior in some, but not all other packages. (DogstatsD doesn't have a problem, Raygun does, etc..)
I have noticed that some nuget packages in assemblies are automatically copied into the parent output directory, but when I look for the setting that controls this, I cannot find it.
I have written dozens of class libraries over the years, and I have never had a problem with 'chained dependency assemblies (a refs b, b refs c, etc.) resolving when I build. It only seems to be some nuget packages that are a problem.
How do I force nuget packages referenced by a class library project to copy into the build directory without an explicit reference in the application?
Ok, I figured this one out.
This is a problem only for the Log4Net & Loggly wrapper assembly combo in particular because it is referenced entirely at runtime. Log4net loads up its required log appenders at runtime, and because .net doesn't see a ref to the assembly at build time, it assumes that it isn't being used and omits copying the required assembly to the bin directory. The solution when you know this is simple, just write an empty dummy method in the referenced library that you can call in the main application. This will cause .net to include the assembly in the build.
While this problem is specific to the Log4net library, it could occur anywhere that you are using an assembly that is only used with runtime reflection.

How to share libraries without using the GAC?

I have a library that is meant to be used by many websites. The way I am doing it now is in the library's properties, I set the "Post-build event command line" to: copy "$(TargetPath)" "$(SolutionDir)\MyWebsite\bin\$(TargetFileName)"
Every time I want a new website to use the shared library, I add a new line like this: copy "$(TargetPath)" "$(SolutionDir)\MyWebsite2\bin\$(TargetFileName)"
Is there an easy or better way to do this besides using the GAC?
In my opinion your problem here is a lack of control about how this library is produced and used by other projects. If I were you (which I'm not :) I'd set about developing the library through a unit test co-project where new functionality can be developed and tested independently. Once that functionality has been implemented and tested to be working within your unit test parameters manually copy the assembly into a "library" folder of the web project that the required the extension of the library in the first place (this folder holds all your compiled assemblies used by that project).
Even better would be to maintain a version system in which you tag the new version of the library so as to keep track of the exact source revision that it's using.
The reason I suggest what may seem like a cumbersome methodology of working is that your current practice makes your existing websites quite brittle as a change made in the library for one site may in fact break one of the other sites... and as the amount of sites you have increases you can't be forever retro testing new versions of the shared library against the existing sites.
It's also for these reasons that I don't recommend using the GAC either.

How do I work with shared assemblies and projects?

To preface, I've been working with C# for a few months, but I'm completely unfamiliar with concepts like deployment and assemblies, etc. My questions are many and varied, although I'm furiously Googling and reading about them to no avail (I currently have Pro C# 2008 and the .NET 3.5 Platform in front of me).
We have this process and it's composed of three components: an engine, a filter, and logic for the process. We love this process so much we want it reused in other projects. So now I'm starting to explore the space beyond one solution, one project.
Does this sound correct? One huge Solution:
Process A, exe
Process B, exe
Process C, exe
Filter, dll
Engine, dll
The engine is shared code for all of the processes, so I'm assuming that can be a shared assembly? If a shared assembly is in the same solution as a project that consumes it, how does it get consumed if it's supposed to be in the GAC? I've read something about a post build event. Does that mean the engine.dll has to be reployed on every build?
Also, the principle reason we separated the filter from the process (only one process uses it) is so that we can deploy the filter independently from the process so that the process executable doesn't need to be updated. Regardless of if that's best practice, let's just roll with it. Is this possible? I've read that assemblies link to specific versions of other assemblies, so if I update the DLL only, it's actually considered tampering. How can I update the DLL without changing the EXE? Is that what a publisher policy is for?
By the way, is any of this stuff Google-able or Amazon-able? What should I look for? I see lots of books about C# and .NET, but none about deployment or building or testing or things not related to the language itself.
I agree with Aequitarum's analysis. Just a couple additional points:
The engine is shared code for all of the processes, so I'm assuming that can be a shared assembly?
That seems reasonable.
If a shared assembly is in the same solution as a project that consumes it, how does it get consumed if it's supposed to be in the GAC?
Magic.
OK, its not magic. Let's suppose that in your solution your process project has a reference to the engine project. When you build the solution, you'll produce a project assembly that has a reference to the engine assembly. Visual Studio then copies the various files to the right directories. When you execute the process assembly, the runtime loader knows to look in the current directory for the engine assembly. If it cannot find it there, it looks in the global assembly cache. (This is a highly simplified view of loading policy; the real policy is considerably more complex than that.)
Stuff in the GAC should be truly global code; code that you reasonably expect large numbers of disparate projects to use.
Does that mean the engine.dll has to be reployed on every build?
I'm not sure what you mean by "redeployed". Like I said, if you have a project-to-project reference, the build system will automatically copy the files around to the right places.
the principle reason we separated the filter from the process (only one process uses it) is so that we can deploy the filter independently from the process so that the process executable doesn't need to be updated
I question whether that's actually valuable. Scenario one: no filter assembly, all filter code is in project.exe. You wish to update the filter code; you update project.exe. Scenario two: filter.dll, project.exe. You wish to update the filter code; you update filter.dll. How is scenario two cheaper or easier than scenario one? In both scenarios you're updating a file; why does it matter what the name of the file is?
However, perhaps it really is cheaper and easier for your particular scenario. The key thing to understand about assemblies is assemblies are the smallest unit of independently versionable and redistributable code. If you have two things and it makes sense to version and ship them independently of each other, then they should be in different assemblies; if it does not make sense to do that, then they should be in the same assembly.
I've read that assemblies link to specific versions of other assemblies, so if I update the DLL only, it's actually considered tampering. How can I update the DLL without changing the EXE? Is that what a publisher policy is for?
An assembly may be given a "strong name". When you name your assembly Foo.DLL, and you write Bar.EXE to say "Bar.EXE depends on Foo.DLL", then the runtime will load anything that happens to be named Foo.DLL; file names are not strong. If an evil hacker gets their own version of Foo.DLL onto the client machine, the loader will load it. A strong name lets Bar.EXE say "Bar.exe version 1.2 written by Bar Corporation depends on Foo.DLL version 1.4 written by Foo Corporation", and all the verifications are done against the cryptographically strong keys associated with Foo Corp and Bar Corp.
So yes, an assembly may be configured to bind only against a specific version from a specific company, to prevent tampering. What you can do to update an assembly to use a newer version is create a little XML file that tells the loader "you know how I said I wanted Foo.DLL v1.4? Well, actually if 1.5 is available, its OK to use that too."
What should I look for? I see lots of books about C# and .NET, but none about deployment or building or testing or things not related to the language itself.
Deployment is frequently neglected in books, I agree.
I would start by searching for "ClickOnce" if you're interested in deployment of managed Windows applications.
Projects can reference assemblies or projects.
When you reference another assembly/project, you are allowed to use all the public classes/enums/structs etc in the referenced assembly.
You do not need to have all of them in one solution. You can have three solutions, one for each Process, and all three solutions can load Engine and Filter.
Also, you could have Process B and Process C reference the compiled assemblies (the .dll's) of the Engine and Filter and have similar effect.
As long as you don't set the property in the reference to an assembly to require a specific version, you can freely update DLLs without much concern, providing the only code changes were to the DLL.
Also, the principle reason we
separated the filter from the process
(only one process uses it) is so that
we can deploy the filter independently
from the process so that the process
executable doesn't need to be updated.
Regardless of if that's best practice,
let's just roll with it. Is this
possible?
I actually prefer this method of updating. Less overhead to update only files that changed rather than everything everytime.
As for using the GAC, whole other level of complexity I won't get into.
Tamper proofing your assemblies can be done by signing them, which is required to use the GAC in the first place, but you should still be fine so long as a specific version is not required.
My recommendation is to read a book about the .NET framework. This will really help you understand the CLR and what you're doing.
Applied Microsoft .NET Framework Programming was a book I really enjoyed reading.
You mention the engine is shared code, which is why you put it in a separate project under your solution. There's nothing wrong with doing it this way, and it's not necessary to add this DLL to the GAC. During your development phase, you can just add a reference to your engine project, and you'll be able to call the code from that assembly. When you want to deploy this application, you can either deploy the engine DLL with it, or you can add the engine DLL to the GAC (which is another ball of wax in and of itself). I tend to lean against GAC deployments unless it's truly necessary. One of the best features of .NET is the ability to deploy everything you need to run your application in one folder without having to copy stuff to system folders (i.e. the GAC).
If you want to achieve something like dynamically loading DLL's and calling member methods from your processor without caring about specific version, you can go a couple of routes. The easiest route is to just set the Specific Version property to False when you add the reference. This will give you the liberty of changing the DLL later, and as long as you don't mess with method signatures, it shouldn't be a problem. The second option is the MEF (which uses Reflection and will be part of the framework in .NET 4.0). The idea with the MEF is that you can scan a "plugins" style folder for DLL's that implement specific functionality and then call them dynamically. This gives you some additional flexibility in that you can add new assemblies later without the need to modify your references.
Another thing to note is that there are Setup and Deployment project templates built into Visual Studio that you can use to generate MSI packages for deploying your projects. MSDN has lots of documentation related to this subject that you can check out, here:
http://msdn.microsoft.com/en-us/library/ybshs20f%28VS.80%29.aspx
Do not use the GAC on your build machine, it is a deployment detail. Visual Studio automatically copies the DLL into build directory of your application when you reference the DLL. That ensures that you'll run and debug with the expected version of the DLL.
When you deploy, you've got a choice. You can ship the DLL along with the application that uses it, stored in the EXE installation folder. Nothing special is needed, the CLR can always find the DLL and you don't have to worry about strong names or versions. A bug fix update is deployed simply by copying the new DLL into the EXE folder.
When you have several installed apps with a dependency on the DLL then deploying bug fix updates can start to get awkward. Since you have to copy to the DLL repeatedly, once for each app. And you can get into trouble when you update some apps but not others. Especially so when there's a breaking change in the DLL interface that requires the app to be recompiled. That's DLL Hell knocking, the GAC can solve that.
We found some guidance on this issue at MSDN. We started with two separate solution with no shared code, and then abstracted the commonalities to a shared assemblies. We struggled with ways to isolate changes in the shared code to impact only the projects that were ready for it. We were terrible at Open/Close.
We tried
branching the shared code for each project that used it and including it in the solution
copying the shared assembly from the shared solution when we made changes
coding pre-build events to build the shared code solution and copy the assembly
Everything was a real pain. We ended up using one large solution with all the projects in it. We branch each project as we want to stage features closer to production. This branches the shared code as well. It's simplified things a lot and we get a better idea of what tests fail across all projects, as the common code changes.
As far as deployment, our build scripts are setup to build the code and copy only the files that have changed, including the assemblies, to our environments.
By default, you have a hardcoded version number in your project (1.0.0.0). As long as you don't change it, you can use all Filter builds with the Process assembly (it only knows it should use the 1.0.0.0 version). This is not the best solution, however, because how do you distinguish between various builds yourself?
Another option is use different versions of the Filter by the same Process. You should add an app.config file to the Process project, and include a bindingRedirect element (see the docs). Whenever the Runtime looks for a particular version of the Filter, it's "redirected" to a version indicated in the config. Unfortunately, this means that although you don't have to update the Process assembly, you'll have to update the config file with the new version.
Whenever you encounter versioning problems, you can use Fuslogvw.exe (fusion log viewer) to troubleshoot these.
Have fun!
ulu

Working with Common/Utility Libraries

At the company I work for we have a "Utility" project that is referenced by pretty much ever application we build. It's got lots of things like NullHelpers, ConfigSettingHelpers, Common ExtensionMethods etc.
The way we work is that when we want to make a new project, we get the latest version of the project from source control add it to the solution and then reference the project from any new projects that get added to the solution.
This has worked ok, however there have been a couple of instances where people have made "breaking changes" to the common project, which works for them, but doesn't work for others.
I've been thinking that rather than adding the common library as a project reference perhaps we should start developing the common library as a standalone dll and publish different versions and target a particular version for a particular project so that changes can be made without any risk to other projects using the common library.
Having said all that I'm interested to see how others reference or use their common libraries.
That's exactly what we're doing. We have a Utility project which has some non project specific useful functions. We increase the version manually (minor), build the project in Release version, sign it and put it to a shared location.
People then use the specific version of the library.
If some useful methods are implemented in some specific projects which could find their way into main Utility project, we put the to a special helper class in the project, and mark them as a possible Utility candidate (simple //TODO). At the end of the project, we review the candidates and if they stick, we move them to the main library.
Breaking changes are a no-no and we mark methods and classes as [Obsolete] if needed.
But, it doesn't really matter because we increase the version on every publish.
Hope this helps.
We use branching in source control; everyone uses the head branch until they make a release. When they branch the release, they'll branch the common utilities project as well.
Additionally, our utilities project has its own unit tests. That way, other teams can know if they would break the build for other teams.
Of course, we still have problems like you mention occasionally. But when one team checks in a change that breaks another team's build, it usually means the contract for that method/object has been broken somewhere. We look at these as opportunities to improve the design of the common utilities project... or at least to write more unit tests :/
I've had the EXACT same issue!
I used to use project references, but it all seems to go bad, when as you say, you have many projects referencing it.
I now compile to a DLL, and set the CopyLocal property for the DLL reference to false after the first build (otherwise I find it can override sub projects and just become a mess).
I guess in theory it should probably be GAC'ed, but if its a problem that is changing a lot (as mine is) this can become problematic..

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