In ubuntu based docker/os
$ ps PID USER TIME COMMAND 1 postgres 0:00 postgres 47 postgres 0:00 postgres: checkpointer process 48 postgres 0:00 postgres: writer process 49 postgres 0:00 postgres: wal writer process 50 postgres 0:00 postgres: autovacuum launcher process 51 postgres 0:00 postgres: stats collector process 52 postgres 0:00 postgres: bgworker: logical replication launcher
Now If run ps -p 1 -o user=, it will get me PID 1 process USER postgres
$ ps -p 1 -o user= postgres
This is what I can do in ubuntu based image/os
Now
I am really seeking for a way to do the same for alpine based image. Where I can run ps command to get PID 1 process USER.
I didn't find any docs/hints around.
There is very cut version of ps in alpine image by default. It is busybox one:
/ # ps --help BusyBox v1.27.2 (2017-12-12 10:41:50 GMT) multi-call binary. Usage: ps [-o COL1,COL2=HEADER] Show list of processes -o COL1,COL2=HEADER Select columns for display
It can only show output with defined columns.
If you want use uncut ps, you need to install it first to alpine image:
/ # apk add --no-cache procps fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/main/x86_64/APKINDEX.tar.gz fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/community/x86_64/APKINDEX.tar.gz (1/6) Installing libintl (0.19.8.1-r1) (2/6) Installing ncurses-terminfo-base (6.0_p20171125-r0) (3/6) Installing ncurses-terminfo (6.0_p20171125-r0) (4/6) Installing ncurses-libs (6.0_p20171125-r0) (5/6) Installing libproc (3.3.12-r3) (6/6) Installing procps (3.3.12-r3) Executing busybox-1.27.2-r7.trigger OK: 13 MiB in 17 packages
Now, you can use it you want:
/ # ps -p 1 -o user= root
