host pid mode in swarm mode. #5624
Description
Problem description
Swarm mode doesn't support host pid mode with pid option?. as my testing It seems not and I couldn't find any information anywhere on that.
As I know, the document remarks some different support between docker-compose and swarm mode. however, when it comes to pid, there is no mention about that pid option is not supported in swarm mode. I want a container to share PID namespace with host OS in swarm mode to manage processes on manager node.
This un-support is on purpose?
Problem location
version: '3.4'
services:
test:
image: ubuntu:16.04
command: tail -f /dev/null
pid: host
$ docker stack deploy -c docker-compose.yml pid_share
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
8a2d4b439efa asleea/simple_test:latest "tail -f /dev/null" 2 hours ago Up 2 hours test_test.qdma0yzo931ydcsuc6z5lef3n.w1h4vwox5o6lmt51ugt01w4a8
$ docker exec -it test_test.qdma0yzo931ydcsuc6z5lef3n.w1h4vwox5o6lmt51ugt01w4a8 top
top - 07:02:53 up 5:09, 0 users, load average: 0.06, 0.04, 0.00
Tasks: 2 total, 1 running, 1 sleeping, 0 stopped, 0 zombie
%Cpu(s): 1.2 us, 0.3 sy, 0.0 ni, 98.5 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 8154208 total, 6221900 free, 691592 used, 1240716 buff/cache
KiB Swap: 8386556 total, 8386556 free, 0 used. 7052380 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
5 root 20 0 36636 2988 2560 R 0.3 0.0 0:00.02 top
1 root 20 0 4412 680 608 S 0.0 0.0 0:00.04 tail
The top command show only processes in the container but host OS.
Project version(s) affected
docker 17.09.0-ce
docker-compose 1.17.0