# git credential cache timeout questions 3 messages from 2021-02-19 to 2021-03-10. Participants: John Ratliff, Jeff King. Thread: https://gitlist.dev/t/55174 ## John Ratliff, 2021-02-19 15:46 Subject: git credential cache timeout questions Message-ID: URL: https://gitlist.dev/e/CAP8UukiL0niGSm3o7uYNBzL3FP-UEgfOuq-Tu%3DfksWJkerT5fg%40mail.gmail.com ``` I have configured my git to cache my credentials for 12 hours using this section in my .gitconfig [credential "https://mygithub.example.edu"] username = myuser helper = cache --timeout 43200 However, the credentials don’t always seem to expire after 12 hours. Sometimes I come back the next morning and the credentials still work. This is generally after leaving at 5:00 PM and coming back in the next day at 9:00 AM, well past the 12 hour timeout. Is there any way to see the current timeout value? Is it a rolling timeout (i.e. any git action resets the timeout)? If it happened once or twice, I would assume I just forgot that I did something with git later than I thought. But this happens frequently enough that it’s difficult to accept that as a possibility. It’s not a daily occurrence. My credentials do expire…I just have no idea when they will. Have I setup my gitconfig section wrong? CentOS 7. Git 2.24.3. Thanks. --John ``` ## Jeff King, 2021-02-19 17:04 Subject: Re: git credential cache timeout questions Message-ID: URL: https://gitlist.dev/e/YC%2FvqJBSnDHoLIdJ%40coredump.intra.peff.net In-Reply-To: ``` On Fri, Feb 19, 2021 at 10:46:48AM -0500, John Ratliff wrote: > I have configured my git to cache my credentials for 12 hours using > this section in my .gitconfig > > [credential "https://mygithub.example.edu"] > username = myuser > helper = cache --timeout 43200 > > However, the credentials don’t always seem to expire after 12 hours. > Sometimes I come back the next morning and the credentials still work. > This is generally after leaving at 5:00 PM and coming back in the next > day at 9:00 AM, well past the 12 hour timeout. > > Is there any way to see the current timeout value? Is it a rolling > timeout (i.e. any git action resets the timeout)? It's the "rolling" thing, though the source is a bit subtle. The credential-cache helper sets an absolute expiration when the value is stored, and it doesn't update it on a "get" request. However, Git's interaction with the helpers is generally: - when we need a credential ask for one - when a credential is rejected by a server, tell helpers to erase it - when a credential is accepted by a server, tell helpers to store it And it's that last one that provides the rolling timeout, because we do it even if the credential came from a helper in the first place! I actually wrote a patch long ago to switch this behavior: https://lore.kernel.org/git/20120407033417.GA13914@sigill.intra.peff.net/ But it turned out some people actually rely on it. :) There's some discussion in that thread about paths forward, and I think I even played around with it back then. But then it sat on my todo list, and now it has been 9 years, so I don't remember if there were good reasons not to push it forward, or if I simply never got around to it (I suspect the latter; nobody had a pressing use case that was solved by avoiding the rolling timeouts, it just seemed to me to be a bit less surprising). I'd be happy if somebody wanted to revisit the topic. (To your other question, "is there a way to see the timeout value", the answer is "not really, without running it under gdb". I wouldn't be opposed to adding more diagnostic output to the daemon. But you can also see some of what's going on by setting GIT_TRACE=1 in the environment, which will show the extra "store" operation being done by Git). -Peff ``` ## John Ratliff, 2021-03-10 15:41 Subject: Re: git credential cache timeout questions Message-ID: URL: https://gitlist.dev/e/CAP8UukgvnxtMLa00jNn-T_sATNMz2qDo6bCVBnWhqqLmqA42Xw%40mail.gmail.com In-Reply-To: ``` Thanks. Now that I know it is a rolling timeout, I was able to narrow my search for anything that might be causing the timer to extend. There is a git helper program I use that has a background refresh that I think I must leave open overnight sometimes. I think this was causing my timeout to be extended. I disabled the background refresh task and the timeout seems to be expiring like I expect now. --John On Fri, Feb 19, 2021 at 12:04 PM Jeff King wrote: > > On Fri, Feb 19, 2021 at 10:46:48AM -0500, John Ratliff wrote: > > > I have configured my git to cache my credentials for 12 hours using > > this section in my .gitconfig > > > > [credential "https://mygithub.example.edu"] > > username = myuser > > helper = cache --timeout 43200 > > > > However, the credentials don’t always seem to expire after 12 hours. > > Sometimes I come back the next morning and the credentials still work. > > This is generally after leaving at 5:00 PM and coming back in the next > > day at 9:00 AM, well past the 12 hour timeout. > > > > Is there any way to see the current timeout value? Is it a rolling > > timeout (i.e. any git action resets the timeout)? > > It's the "rolling" thing, though the source is a bit subtle. The > credential-cache helper sets an absolute expiration when the value is > stored, and it doesn't update it on a "get" request. > > However, Git's interaction with the helpers is generally: > > - when we need a credential ask for one > > - when a credential is rejected by a server, tell helpers to erase it > > - when a credential is accepted by a server, tell helpers to store it > > And it's that last one that provides the rolling timeout, because we do > it even if the credential came from a helper in the first place! > > I actually wrote a patch long ago to switch this behavior: > > https://lore.kernel.org/git/20120407033417.GA13914@sigill.intra.peff.net/ > > But it turned out some people actually rely on it. :) > > There's some discussion in that thread about paths forward, and I think > I even played around with it back then. But then it sat on my todo list, > and now it has been 9 years, so I don't remember if there were good > reasons not to push it forward, or if I simply never got around to it (I > suspect the latter; nobody had a pressing use case that was solved by > avoiding the rolling timeouts, it just seemed to me to be a bit less > surprising). I'd be happy if somebody wanted to revisit the topic. > > (To your other question, "is there a way to see the timeout value", the > answer is "not really, without running it under gdb". I wouldn't be > opposed to adding more diagnostic output to the daemon. But you can also > see some of what's going on by setting GIT_TRACE=1 in the environment, > which will show the extra "store" operation being done by Git). > > -Peff ```