Hi,
stdout is not tty, but dpkg still produces a lot of output:
$ docker stop apt-quiet \
; docker run --rm --name apt-quiet -d cypress/base:12 sleep infinity \
&& docker exec apt-quiet sh -euxc '
[ -t 1 ] && echo tty || echo non-tty
&& ps -efH
&& export DEBIAN_FRONTEND=noninteractive
&& apt-get -qq update
&& apt-get -qq install less
'
apt-quiet
10ff09dfe813df80917d6a4b180f616c54ecd78267739eb5e0c79927410e55a4
non-tty
+ [ -t 1 ]
+ echo non-tty
+ ps -efH
UID PID PPID C STIME TTY TIME CMD
root 7 0 0 13:08 ? 00:00:00 sh -euxc [ -t 1 ]
&& echo tty || echo non-tty && ps -efH && export
DEBIAN_FRONTEND=noninteractive && apt-get -qq update && apt-get -qq
install less
root 12 7 0 13:08 ? 00:00:00 ps -efH
root 1 0 28 13:08 ? 00:00:00 sleep infinity
+ export DEBIAN_FRONTEND=noninteractive
+ apt-get -qq update
+ apt-get -qq install less
debconf: delaying package configuration, since apt-utils is not installed
Selecting previously unselected package less.
(Reading database ... (Reading database ... 5% (Reading database ...
10% (Reading database ... 15% (Reading database ... 20% (Reading
database ... 25% (Reading database ... 30% (Reading database ... 35%
(Reading database ... 40% (Reading database ... 45% (Reading database
... 50% (Reading database ... 55% (Reading database ... 60% (Reading
database ... 65% (Reading database ... 70% (Reading database ... 75%
(Reading database ... 80% (Reading database ... 85% (Reading database
... 90% (Reading database ... 95% (Reading database ... 100% (Reading
database ... 33231 files and directories currently installed.)
Preparing to unpack .../less_487-0.1+b1_amd64.deb ...
Unpacking less (487-0.1+b1) ...
Setting up less (487-0.1+b1) ...
Processing triggers for mime-support (3.62) ...
Regards,
Yuri
