AzCopy should use %LOCALAPPDATA%\AzCopy on Windows, not %USERPROFILE%\.azcopy

[daiplusplus]

Did you search for prior issues before submitting a new issue?

Yes:

• None of the existing issues matching "appdata" were relevant.
• Ditto for "roaming".
• This particular issue was almost touched-on in Do we need to write logs to ~/.azcopy directory? #221 - though that issue is now closed.

Which version of the AzCopy was used?

Note: The version is visible when running AzCopy without any argument

v10.16.2

Which platform are you using? (ex: Windows, Mac, Linux)

Windows 10, Windows 11

What command did you run?

(Any command)

What problem was encountered?

• AzCopy uses C:\Users\Me\.azcopy\ for its local-only data.
  • ...which gets copied around the network when Roaming Profiles are enabled. Not good.
• Using the user-profile root means seldom-used directories start to pile-up in the navigation sidebar.
• This behaviour violates Microsoft's own guidelines and requirements for software targeting Windows:
  • I'll divert your attention towards the Windows 10 Certification requirements for Windows Desktop Apps (emphasis mine):

  • Your app’s data that is exclusive to a specific user and that is not to be shared with other users of the computer, must be stored in Users\<username>\AppData

• Finally, the comments in init_windows.go and platdiff_windows.go describe using "local appdata" even though this is presently not the case:

azure-storage-azcopy/testSuite/cmd/platdiff_windows.go

Lines 10 to 13 in ffcdb9e

	// GetAzCopyAppPath returns the path of Azcopy in local appdata.
	func GetAzCopyAppPath() string {
	userProfile := common.GetEnvironmentVariable(common.EEnvironmentVariable.UserDir())
	azcopyAppDataFolder := path.Join(userProfile, ".azcopy")

azure-storage-azcopy/common/init_windows.go

Lines 28 to 31 in ffcdb9e

	// getAzCopyAppPath returns the path of Azcopy in local appdata.
	func getAzCopyAppPath() string {
	userProfile := GetEnvironmentVariable(EEnvironmentVariable.UserDir())
	azcopyAppDataFolder := strings.ReplaceAll(path.Join(userProfile, ".azcopy"), "/", `\`)

How can we reproduce the problem in the simplest way?

Just use azcopy as normal.

Have you found a mitigation/solution?

Yes:

• In common/environment.go add LocalDataDir() which uses LOCALAPPDATA on Windows:

  func (EnvironmentVariable) LocalDataDir() EnvironmentVariable {
  	// Only used internally, not listed in the environment variables.
  	return EnvironmentVariable{
  		Name: Iff(runtime.GOOS == "windows", "LOCALAPPDATA", "HOME"),
  	}
  }

• In common/init_windows.go, use LocalDataDir instead of UserDir:

  // getAzCopyAppPath returns the path of Azcopy in local AppData. // e.g. C:\Users\billg\AppData\Local\AzCopy
  func getAzCopyAppPath() string {
  	localAppData := GetEnvironmentVariable(EEnvironmentVariable.LocalDataDir())
  	azcopyLocalAppDataFolder := strings.ReplaceAll(path.Join(localAppData , "AzCopy"), "/", `\`)
  
  	return azcopyLocalAppDataFolder
  }

  • However, it does make sense to continue using .azcopy if it's already in use, so an alternative approach might be:

    // getAzCopyAppPath returns the path of Azcopy in local AppData. // e.g. C:\Users\billg\AppData\Local\AzCopy
    func getAzCopyAppPath() string {
    	userProfile := GetEnvironmentVariable(EEnvironmentVariable.UserDir())
    	userProfileDotAzCopy := strings.ReplaceAll(path.Join(userProfile, ".azcopy"), "/", `\`)
    	if err := os.Mkdir(azcopyAppDataFolder, os.ModeDir); err != nil {
    		if os.IsExist(err) {
    			return userProfileDotAzCopy 
    		}
    	}
    
    	localAppData := GetEnvironmentVariable(EEnvironmentVariable.LocalDataDir())
    	azcopyLocalAppDataFolder := strings.ReplaceAll(path.Join(localAppData , "AzCopy"), "/", `\`)
    
    	return azcopyLocalAppDataFolder
    }

• In platdiff_windows.go, similarly use LocalDataDir instead of UserDir:

  // GetAzCopyAppPath returns the path of AzCopy in local appdata // e.g. C:\Users\billg\AppData\Local\AzCopy
  func GetAzCopyAppPath() string {
  	localAppData := common.GetEnvironmentVariable(common.EEnvironmentVariable.LocalDataDir())
  	azcopyLocalAppDataFolder := path.Join(localAppData , "AzCopy")
  	if err := os.Mkdir(azcopyAppDataFolder, os.ModeDir); err != nil && !os.IsExist(err) {
  		return ""
  	}
  	return azcopyAppDataFolder
  }

I'm happy to submit this as a PR if everyone's happy with it.