diff options
| -rw-r--r-- | src/init/s6-linux-init.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/src/init/s6-linux-init.c b/src/init/s6-linux-init.c index 4168523..e6b0d60 100644 --- a/src/init/s6-linux-init.c +++ b/src/init/s6-linux-init.c @@ -119,11 +119,12 @@ static inline void run_stage2 (char const *basedir, char const **argv, unsigned /* This is ugly voodoo, keep away from innocent eyes. - If stdin is a terminal, it means we're in a "docker run -it" container -(or equivalent) and stdin is a ctty. We don't want the supervision tree to -have this ctty (else ^C kills everything) but we want stage 2 to keep it, -so that if we have a CMD run by stage 2 (as is the case with s6-overlay), -it remains interactive (control sequences can be sent to it). + If ttyfd exists, it means we're in a "docker run -it" container or +equivalent, and ttyfd (a copy of the original stdin) is a ctty. We don't +want the supervision tree to have this ctty (else ^C kills everything) +but we want stage 2 to keep it if possible, so that if we have a CMD run +by stage 2 (as is the case with s6-overlay), it remains interactive, i.e. +control sequences can be sent to it. In order to achieve that, we have the child (future stage 2) steal the ctty from the parent (future s6-svscan). But that may not work, for instance in a USER container, where we don't have the appropriate permissions; in |