Re: [systemd-devel] Soliciting feedback for golang bindings to the systemd journal C API
- Original Message - > From: "Brandon Philips" > To: "Zbigniew Jędrzejewski-Szmek" > Cc: "Dan Mace" , "systemd Mailing List" > , > appinfra-l...@redhat.com > Sent: Thursday, June 19, 2014 3:28:06 PM > Subject: Re: [systemd-devel] Soliciting feedback for golang bindings to the > systemd journal C API > > On Sat, Jun 14, 2014 at 8:13 AM, Zbigniew Jędrzejewski-Szmek > wrote: > > I think that designing the api in steps like this will make it harder > > to get a consistent design. The journal api is rather small, so I don't > > think it is hard to cover most of it in the initial design. In my > > experience, getting sd_journal_print, sd_journal_send, sd_journal_sendv > > wrappers consistent requires some care. > > I agree, I would rather do this all at once. Agree. > > About the proposed go api: > > > > I think the reader and writer apis should be totally separate. > > Different files/modules/whatever. They don't share implementation, > > and usually are not used together. Agree. > Yes, I agree. Actually, is there a reason to bind to the C > sd_journal_print if we already have a pure Go version of > sd_journal_send? > https://github.com/coreos/go-systemd/blob/master/journal/send.go > > > In some places in the go code '%s' is used with numerical 'err'. > > Does this work at all? > > Yes it works, Go's print is typesafe but it will look strange: > %!s(int=42). We should probably turn them into syscall.Errno() type. Oversights on my part. This is rough POC code. I agree they should be translated. > > It's hard to say with the scant backtrace. But I don't recall > > ever seeing any crashes related to sd_journal_wait. > > Dan, how do you want me to help out with this? I am happy to dig in if > you want to share a branch or something. Or you can send a PR and we > can start from there. > > Brandon > > [1] http://play.golang.org/p/zTOuMj-sg7 > [2] http://play.golang.org/p/NDnJF8Zocf > This is on my backburner at the moment while I work on some other things. Hitting the segfault while testing our primary use case and being unable to reproduce the error made me nervous enough that I don't feel comfortable promoting any of the current work yet. I was hoping something obvious would jump out, or somebody else running the test from my branch would be able to observe the segfault and have a better ability to debug. My branch[1] is still in the same state as before. I don't think a PR makes sense quite yet until there's increased confidence in the stability. Without knowing the cause, I can't predict the impact to the design that might come with the solution. -- Dan [1] https://github.com/ironcladlou/go-systemd/compare/cgo-journal ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Soliciting feedback for golang bindings to the systemd journal C API
- Original Message - > From: "Brandon Philips" > To: "Dan Mace" > Cc: appinfra-l...@redhat.com, systemd-devel@lists.freedesktop.org > Sent: Tuesday, June 10, 2014 1:08:59 PM > Subject: Re: [systemd-devel] Soliciting feedback for golang bindings to the > systemd journal C API > > On Mon, Jun 9, 2014 at 11:56 AM, Dan Mace wrote: > > http://fpaste.org/107299/14019224/ > > Hrm, odd. Was it with the given tests? I will try it out and see if I > can reproduce. I don't see anything immediately wrong in the code. > > Thanks, > > Brandon > Brandon, The error was observed running this test: https://github.com/ironcladlou/go-systemd/blob/cgo-journal/journal/journal_test.go The test was executed in a Fedora 20 VirtualBox VM on a Fedora 20 host. I'm CC'ing Jhon Honce who is the only human who actually witnessed the panic. Thanks for looking into it, and sorry I don't have more information! -- Dan ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Soliciting feedback for golang bindings to the systemd journal C API
- Original Message - > From: "David Timothy Strauss" > To: "Dan Mace" > Cc: appinfra-l...@redhat.com, "systemd Mailing List" > > Sent: Monday, June 9, 2014 8:29:11 PM > Subject: Re: [systemd-devel] Soliciting feedback for golang bindings to the > systemd journal C API > > The CoreOS crew has already done most of this work by writing a native > Go implementation (rather than wrapping the C APIs). > Can you please point me to the implementation? All I've seen is this: https://github.com/coreos/go-systemd/blob/master/journal/send.go Which only handles writes via the Unix socket. The implementation we're prototyping supports journal queries in ways that (to my knowledge) aren't possible without either forking to external tools (e.g. journalctl) or linking to sd-journal. If there's already code out there which satisfies the need, I'd be happy to use and contribute to it. -- Dan Mace OpenShift, PaaS by Red Hat ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
[systemd-devel] Soliciting feedback for golang bindings to the systemd journal C API
Hello! We've been working on golang bindings to the systemd journal interface (sd-journal.h), as well as a higher level go API which builds on the bindings. The immediate goal is to replace the use of forked calls to journalctl in a project. To that end, we've been wrapping only the subset of sd-journal.h necessary to build the go API necessary to support existing journalctl usages. The work is currently taking place in my fork of the go-systemd project: https://github.com/ironcladlou/go-systemd/compare/cgo-journal (The only test code there is a work-in-progress scratchpad I've been using for iterative development- actual tests are forthcoming once we're satisfied there won't be any more API churn.) We've observed a segfault during this simple test, but only once: http://fpaste.org/107299/14019224/ I've had no success reproducing the segfault. My first thought was a race when closing the journal while dealing with the setup or execution of sd_journal_wait, but no amount of concurrent closing or other access to the sd_journal instance has led me to the same error. Any advice for reproducing the segfault would be greatly appreciated. We're interested in getting feedback on the cgo bindings and go API. Does anybody else out there see a need for these bindings? All suggestions and contributions are very welcome. -- Dan Mace OpenShift, PaaS by Red Hat ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
