Windows paths not supported by default file sink

[Apeopex]

When using absolute Windows paths, url.Parse does not retreieve the "file" scheme.

panic: couldn't open sink "C:\\Users\\...\\AppData\\Roaming\\...\\info.log.json": no sink found for scheme "c"

Appending, "file:///" (golang/go#6027 (comment)) does not work as expected. (Ref: golang/go#13276 )

zap/sink.go

Line 99 in ff33455

u, err := url.Parse(rawURL)

Ref: golang/go#13276 (comment)
Changed by PR: #606

Temporary workaround:

func newWinFileSink(u *url.URL) (zap.Sink, error) {
    // Remove leading slash left by url.Parse()
    return os.OpenFile(u.Path[1:], os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0644)
}
zap.RegisterSink("winfile", newWinFileSink)
zap.Config{
    OutputPaths: []string{"stdout", "winfile:///" + filepath.Join(GlobalConfigDir.Path, "info.log.json")},
}

[wenzhihong2003]

yes, in windows file:///d:/a/wen88.log is not supported. Because, in this scene, url.Path is /d:/a/wen88.log, in windows you can't create file start with /, so in windows, you will strip the /.

[wenzhihong2003]

I have pull a request in #624

[prashantv]

The reason file:///d:/a/wen88.log doesn't work is that the path is /d:/a/..., can you replace the 3 / with 2 /, e.g., file://d:/a/wen88.log?

[Apeopex]

I did try that and ran into the same issue listed here: golang/go#13276

With backslashes:
panic: couldn't open sink "file://C:\\Users\\~~\\Documents\\Web Development\\~~\\build\\info.log.json": can't parse "file://C:\\Users\\~~\\Documents\\Web Development\\~~\\build\\info.log.json" as a URL: parse file://C:\Users\~~\Documents\Web Development\~~\build\info.log.json: invalid character "\\" in host name

With forward slashes:
panic: couldn't open sink "file://C:/Users/~~/Documents/Web Development/~~/build/info.log.json": file URLs must leave host empty or use localhost: got file://C:/Users/~~/Documents/Web%20Development/~~/build/info.log.json

[wenzhihong2003]

@prashantv , if use file://d:/a/wen88.log , it will paic with message

couldn't open sink "file://d:/a/wen88.log": file URLs must leave host empty or use localhost: got file://d:/a/wen88.log

because, file://d:/a/wen88.log parse to url.URL,

Host = "d:"
Path = "/a/wen88.log"

it will panic in https://github.com/uber-go/zap/blob/master/sink.go#L130

if hn := u.Hostname(); hn != "" && hn != "localhost" {
    return nil, fmt.Errorf("file URLs must leave host empty or use localhost: got %v", u)
}

[prashantv]

That makes sense, thanks. It looks like it has to be 3 slashes, and is covered here:
https://blogs.msdn.microsoft.com/ie/2006/12/06/file-uris-in-windows/

Is there any other examples of Go libraries that parse Windows file URIs?

[sethkor]

Any update on this one, i'm running into this issue right now on windows

[whatsadebugger]

I just had the same problem. Might need to look into dimrocs pr and add those changes manually.

[whatsadebugger]

smartcontractkit/chainlink#977 copy logger_unix and _windows. Call the the registerOSSinks method to register the sink and you're good to go.

[izikorgad]

+1

[Againster]

+1, it still didn't work

[Mario-Hofstaetter]

Dear maintainers, 3 years later this issue is still open and is breaking logging in https://github.com/open-telemetry/opentelemetry-collector

Is there any workaround yet that does not involve source changes? (which is not possible because we use otelcol release)

PR #624 was unfortunately never finished.

[abhinav]

@Mario-Hofstaetter
Unfortunately, this has been a pretty low priority issue because we don't use Windows at work, and none of the active maintainers have Windows machines at home to be able to debug and fix this.

My feeling is that is that some mix of filepath.ToSlash/FromSlash will help solve this (I made an attempt in #999 last year), but the edit-test-debug loop was slow enough that I stopped trying.

[kmahyyg]

@Mario-Hofstaetter Unfortunately, this has been a pretty low priority issue because we don't use Windows at work, and none of the active maintainers have Windows machines at home to be able to debug and fix this.

My feeling is that is that some mix of filepath.ToSlash/FromSlash will help solve this (I made an attempt in #999 last year), but the edit-test-debug loop was slow enough that I stopped trying.

I understand that this issue is low-priority since you never use Windows at work. Golang is shipped with cross-platform ability, this issue really make users exhausted.

[prashantv]

There is some limited Windows support as of #1159

I think that change should have made v1.24 (@sywhang I don't see it in the release changelog, my PR didn't update the CHANGELOG, so it may have been missed?)

[yehudamakarov]

funny, my zap logger is breaking on windows and i guess this is why.

Is the below still the recommended fix?

When using absolute Windows paths, url.Parse does not retreieve the "file" scheme.

panic: couldn't open sink "C:\\Users\\...\\AppData\\Roaming\\...\\info.log.json": no sink found for scheme "c"

Appending, "file:///" (golang/go#6027 (comment)) does not work as expected. (Ref: golang/go#13276 )

zap/sink.go

Line 99 in ff33455

u, err := url.Parse(rawURL)

Ref: golang/go#13276 (comment) Changed by PR: #606

Temporary workaround:

func newWinFileSink(u *url.URL) (zap.Sink, error) {
    // Remove leading slash left by url.Parse()
    return os.OpenFile(u.Path[1:], os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0644)
}
zap.RegisterSink("winfile", newWinFileSink)
zap.Config{
    OutputPaths: []string{"stdout", "winfile:///" + filepath.Join(GlobalConfigDir.Path, "info.log.json")},
}