Auto Updating Winform Application Used Over Remote Desktop - c#

We have an app we wrote deployed onto our terminal servers at work, and keeping it up-to-date is a bit of a pain.
What update mechanisms do people use for app on terminal servers? At the moment we manually copy the new exe + dependencies on witch is just rubbish.
I'm a bit concerned about files being locked by users when trying to update, i cant really just kill the process in case someone is in the middle of doing something. We would like to be able to handle the odd fat client update as well.
Ideally we'd plug something into teamcity/octopus but are open to suggestions

Create a script that copies the exe file to a user specific temp folder, then launches the copied exe. To make the script more efficient, you can have it check the dates of the files. If they are different, then you copy the file over the old one located in the temp folder, else you just launch it.

Related

How to programmatically determine which process created a file in .net?

There are several threads on SO that describe how to check which application creates a file with tools like Sysinternals process monitor. Is something like this possible programmatically from .net?
Background: My program has to remote-control a proprietary third party application using its automation interface, and one of the functions I need from this application has a bug where it creates a bunch of temporary files in %TEMP% that are called tmpXXXX.tmp (the same as .net's Path.GetTempFileName() does) but does not delete them. This causes the C drive to become full over time, eventually failing the application. I already filed a bug to the manufacturer, but we need a temporary workaround for the time being, so I thought of putting a FileSystemWatcher on %TEMP% that watches tmp*.tmp, collects these files, and after the operation on the third-party application finishes, deletes them. But this is risky as another application might also write files with the same file name pattern to %TEMP% so I only want to delete those created by NastyBuggyThirdPartyApplication.exe.
Is this anyhow possible?
This kind of things is possible, but maybe a bit tricky.
To know who created the file, look at the user that owns it. Therefore you might need to create a specific user, and that application will run under this specific user. In order to do that, you need to create a small application that will start your buggy app by impersonating another user, so anything done within the app will be under this user so as file creating...
I don't know how to monitor and get triggered when a file is created, but nothing can prevent you from setting a timer that wakes up every five or ten minutes, then checks if any file in the directory is owned by the application user and closed, so it deletes it.
Maybe if they react fast for this bug fixing, you won't need your app very long time. So another solution, if possible might just to change the Temp folder into another drive, which has lots of space...
One solution is that you use a FileWatcher to automatically delete all the files but before deleting you should check if the file is not currently locked or used by other process, for example the Sysinternal Suite has a tool called handle.exe that can do this. Use it from the command line:
handle.exe -a
You can invoke this from a c# program (there might be some performance issues though)
So what you would do is when a file is created you verify if it is in use or locked (for example u can use the code provided in Is there a way to check if a file is in use?) and then delete it.
Most of the time when an app is using a temp file it will lock it to prevent just what you fear, that you might delete files from other processes.
As far as I can tell there is no sure way to identify which process created a specific file.

Distribute application from network share (autostart)

I have an application that I want to share on my company's network share. It's a .exe with some .dll's.
We have ~40 users who will need this program. We want it to autostart with the computer.
The problem rises when we need to update the application. Because some of the users might have the application running we cannot delete the .exe and replace it with a new one...
Some say I should use .NET "ClickOnce", but it would'nt work with autostart, right?
What would be the best way to do this? Have a seperate .exe that copies the application to the users temp-folder and then run it from there?
I have the same setup. I have the exe as read only. This way I can replace the .exe and make it read only again. When the user restarts the application it has the updated version.
You can set it read only by right clicking -> properties -> check read only.
To auto start it, just add a shortcut to the start up folder.

Reliably copy files from one server to another using c#

I am looking for a programmatic way to copy files from one network drive to another. I have created a program that does a simple copy but this is not enough as the line is not reliable and the files ends up being corrupted. Is there a technology that syncs the folders and does a sum-check or something like that.
I need it to be a c# app as I need to know when the copy is completed so I can process the files on the other side. I am using windows services to co-ordinate this.
I'm just looking for someone to point me in the right direction with tutorials if necessary.
What you are looking for is Robocopy (aka Robust Copy), it is built in to windows Vista and newer and it has features to retry on network failure.
One down side is there is no "Verify" functionality built in, but if you need to you can use a 3rd party file hashing program and put the copy in a script that verifies the hashes after the copy completes.
Here is a query that copies all files and sub-folders in a restartable mode, if a copy fails it will re-try 1,000,000 times by default waiting 30 seconds between tries. (you can change that with /r:<N> and /w:<N> where <N> is a number)
robocopy C:\SourceFolder \\DestComputer\DestFolder /zb /e
The only time I have ever done anything like this has been during the deploy process to distributed servers. In that instance I zipped the files, moved and unzipped them using PSEXEC.
If I were you, I would begin by figuring out how to zip the files (To prevent the corruption issues you have described) and then worry about how to move them.

Rename a running executable (exe) file [duplicate]

This question already has answers here:
Why does rename a loaded .net assembly work?
(3 answers)
Closed 5 years ago.
We are trying to push updates to multiple servers at once and my manager has found that it is possible to rename running .exe file. Using that knowledge he wants to rename a running exe and copy over a new version of said exe such that anyone running their in memory copy of foo.exe are fine and anybody who opens a shortcut pointing to foo.exe will get a new copy with updates applied.
I guess I need to clarify, He doesn't expect the old copy to magically update, he just expects them to keep running the old copy until they open the exe again, in which case it will then open the new one that has the name of the old one.
It sometimes throws an exception that the file is in use on his program but if he tries renaming it in a loop it will eventually succeed. On my machine I have yet to be able to get it to work even in a loop.
My first and main question is this: Is it ever acceptable to do this. Should renaming a running executable ever be a valid scenario?
Secondly, if it is a valid scenario then how could one reliably do this? Our current thoughts are try a bunch of times using File.Move (C#) to do a rename and if it doesn't work then write out to an error log so it can be handled manually.
An airplane mechanic and a surgeon meet in a bar. The mechanic says "you know, we have basically the same job. We take broken stuff out and put new, better parts in." The surgeon says "yeah, but you don't have to keep the plane flying as you're making the repairs!"
Trying to update an application by moving files while the application is running seems about as dangerous as trying to fix an airplane in flight. Possible? Sure. Greatly increased risk of catestrophic crash? Yep.
If the application you are updating is a managed application, consider using ClickOnce Deployment. That way, the next time someone runs the application, if there is a new version available it will be copied down and installed automatically. That's much more safe and pleasant than trying to mess with an application while its still running.
No, this is not acceptable. Do not do this. This is not a valid deployment mechanism. This should have been yours or his first clue:
It sometimes throws an exception that the file is in use on his program but if he tries renaming it in a loop it will eventually succeed.
And it won't work, anyway. His theory is quite wrong:
Using that knowledge he wants to rename a running exe and copy over a new version of said exe such that anyone running their in memory copy of foo.exe are fine and anybody who opens a shortcut pointing to foo.exe will get a new copy with updates applied.
Specifically, the copy in memory will not be automatically replaced with the new executable just because it has the same name. The reason that you're allowed to rename the executable in the first place is because the operating system is not using the file name to find the application. The original executable will still be loaded, and it will remain loaded until you explicitly unload it and load the new, modified executable.
Notice how even modern web browsers like Chrome and Firefox with their super fancy automatic, in the background, no one ever notices that they exist, updaters still have to close and relaunch the application in order to apply the updates.
Don't worry about shooting the messenger here. It's more likely that your customers and your tech support department will shoot you first.
See number 1.
In our organization, we solved the problem of Updates by having two release folders say EXE_A and EXE_B. We also have a release folder called EXE which only has links ALL of which points to either to EXE_A or EXE_B from which the user runs the applications.
When we publish a new version of the program, we publish it to the folder that is not referenced in the links and then update the links (EXE). In this way, you do not get into exceptions that users are holding the application / assemblies. Also if a user wants to run the updated version, all he need to do is close / re-execute the link in EXE folder.
If you use Windows Vista/Server2k8 or newer you could use mklink to create a symbolic link to the folder containing your application and start the application out of the "symblic linked folder" and then at the update create a new folder, e.g. "AppV2" and change the SymLink to that folder, so the next time the user restarts the application he starts it out of the new folder without noticing.
Renaming open files is ALWAYS a bad choice!
But in general I would think of a better deployment strategy anyway, because if you need to use such "hacks" it is always a messy situation. I don't know your application, but maybee ClickOnce would be a point to start, because you can configure it to check for updates on every start...

How to check if application runs from \program files\

Is there a reliable method to check if an application is run from somewhere beneath program files?
If the user installs the application to program files on local machine, we need to put writable files somewhere else to avoid virtualization on Vista and Win7. When installed to a network disk, though, we want to keep these files with the installation for shared access among users.
Today we do an string comparison between startup path and CSIDL_PROGRAM_FILES, but something tells me this is a very unreliable method.
Any smart solution out there?
Is there a 'IsRunningFromProtectedFolder( )'-api that I do not know about?
Are there any other folders giving the same problems as program files do?
This is not a terribly good idea, as a user can install it wherever they want to, and then the check might fail. Instead have a checkbox when the user installs the app, deciding if it is installed locally or on a server.
As you I also found problems dealing with UAC folder virtualization.I suggest a workaround, it seems that it should work.
It comes from the assumption that elevated processes always use original copies and not the virtualized ones (CMIIW). Also I assume that you setup processed was executed elevated
The idea is to create a "general" process (non-elevated, legacy), that your main installer should run. This process will create a file name in the user chosen folder with a name and contents that both your programs know (for example, test73819704.bin). If the folder virtualized, this file should appear in the user VirtualStore and SHOULD NOT in the original one (from the point of view and privileges of the installer).
So for chosen C:\Program_Files_But_Not_Necessarily and Process-1 (elevated)
Process-1 ensures there's no file C:\Program_Files_But_Not_Necessarily\test73819704.bin
It launches Process-2 with no elevation
Process-2 creates C:\Program_Files_But_Not_Necessarily\test73819704.bin and checks whether it really exists. If exists it would return with a good return code, otherwise with a "failed" one.
Process-1 waits for Process-2 and analize the result. If good, checks for C:\Program_Files_But_Not_Necessarily\test73819704.bin, if it exists, go for "Bingo! No virtualization occured", if doesn't exist, "Bad, let's find some other storage place". If the code from the Process-2 is "failed" one, show the user some error message.
Unfortunately I could not test it right now, but I guess it should work and there's a logic behind this, with Process-2 you just emulate the behavior of your main program )
We allow our users to install anywhere...
If the user has taken the default, and is installed in Program Files, we make the assumption that we need to write to Documents and Settings/Users. Otherwise, we write our data to a folder under the directory the software is in. This of course can still cause problems, and the install does indeed allow people to choose a different data location if they choose to not go for the default.
On top of that, it's a simple ini file change and a copy to move the data.
On start up we detect if we are in the Program Files directory by comparing the value we obtain from SHGetFolderPath(CSIDL_PROGRAM_FILES) with the start of the path the executable is in.

Categories