Be more clear in --help what the value of --log is supposed to be

[lgommans]

Currently, --help says:

...
   --listen string        listen address (default ":8000")
   --log string           log HTTP requests in the combined log format
   --max-size int         the maximum size of the repository in bytes
...

I looked through the documentation and even gave the source code a glance to find what this "string" is supposed to be, which options exist? I just want it to dump the URI or something, whatever the syntax is for that in this combined format, why is an argument even required and can't I use some default?

Some %s-like guesses later and not seeing any log messages at all upon doing requests to the server, I moved on and did an ls for unrelated reasons, finding that it had created my attempts as filenames. Aha, it has to be a filename! It doesn't simply log to stdout!

This pull request hopefully makes that more clear for those who come after me. I found it hard to find good phrasing without making it overly long. I'd actually rather replace the word "string" with "filename" (or just "file") and leave the rest as-is, but I'm not sure if that's possible without overcomplicating things.

The proposed change would appear as:

...
   --listen string        listen address (default ":8000")
   --log string           write HTTP requests in the combined log format to the specified filename
   --max-size int         the maximum size of the repository in bytes
...

The --no-verify-upload option is the only one that is still (significantly) longer, but it's also a bit of an exception so that's not a great measure.

(If a changelog entry is needed for this change, just let me now. I've marked it as not applicable in the checklist because it seems too trivial for an entry.)

Checklist

• I have enabled maintainer edits for this PR
• n/a I have added tests for all changes in this PR
• n/a I have added documentation for the changes (in the manual)
• n/a There's a new file in changelog/unreleased/ that describes the changes for our users (template here)
• I have run gofmt on the code in all commits
• All commit messages are formatted in the same style as the other commits in the repo
• I'm done, this Pull Request is ready for review

[MichaelEischer]

LGTM. Thanks for the cleanup.

[mirabilos]

Huh, so a filename is expected… I was wondering what the string was supposed to be…

… but it doesn’t work with a filename either:

error: open /dev/stdout: permission denied

[lgommans]

That's a special file, try a regular file that you have permissions to create and write to?

For me, though, it also works with this special /dev "file": rest-server --log /dev/stdout --no-auth --path /tmp/test and then curl localhost:8000 (default port) shows up in the stdout whereas without --log /dev/stdout it does not.

[mirabilos]

@lgommans I need it on stdout though, so it can be combined with the rest of the output into the service manager’s logging (and timestamping and rotating) system (here: DJB dæmontools)

A separate actual file is no option.

(Ideally, they’d allow - for stdout.)

[lgommans]

Might it be that you're not running it from bash or a similar shell and /dev/stdout thus does not exist? I think it's some special file that bash somehow emulates (I'm not sure if I remember this correctly).

If that's the case, maybe run it with bash -c 'rest-server --...', else I don't really have an idea how to solve it. Might be that you have to contribute a patch to rest-server such that - is stdout; or it might be that these djb tools need a patch to work with log files or fifos or so.

(The above occurred to me while I was actually typing that I can't reproduce your issue so I wasn't sure how to further help without further information. If this missing stdout 'device' isn't it, then you'll have to give more info.)

[mirabilos]

The link does exist, but I suspect that, as soon as stdout is piped to somewhere, the opening fails, because:

l-wx------ 1 resticd resticd 64 Apr 17 23:42 1 -> pipe:[41829]

(from /proc/$pid/fd/)

I guess it opens for more than appending?

[mirabilos]

Hm, no, it isn’t even that.

nobody@cafe:/ $ /tmp/rest-server --log /dev/stdout --no-auth --path /tmp/test
Data directory: /tmp/test
Authentication disabled
error: open /dev/stdout: permission denied
1|nobody@cafe:/ $ /tmp/rest-server --log /dev/fd/1 --no-auth --path /tmp/test
Data directory: /tmp/test
Authentication disabled
error: open /dev/fd/1: permission denied
1|nobody@cafe:/ $ ls -l /dev/stdout /dev/fd/1
lrwx------ 1 nobody nogroup 64 Apr 17 23:45 /dev/fd/1 -> /dev/pts/0
lrwxrwxrwx 1 root   root     4 Apr 14 00:01 /dev/stdout -> fd/1
nobody@cafe:/ $ ls -l /dev/fd
lrwxrwxrwx 1 root root 13 Apr 14 00:01 /dev/fd -> /proc/self/fd

[lgommans]

I guess it opens for more than appending?

--log sets the server.Log option. When searching for use of server.Log, it shows up in mux.go#L95. The next line calls into a function defined earlier in the file and there the next line contains the file open options.

The code base is not that large. I often have trouble navigating established (read: large) projects in languages which I'm not very familiar with, but this project is imo quite accessible so I figured I'd show how I approached this :). At any rate, the call looks like this:

os.OpenFile(s.Log, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)

Since that works fine for me, I'm not sure if/how this helps, though. Maybe you know more about this.

[mirabilos]

--log - was added in #217 (thanks!)