attach process running in docker

attach_process_running_in_docker

-- find the PID of the process that is blocked, you can use pg_stat_activity or anything else
-- we'll use PID in the next steps
-- assume that we find it as 6939

-- the PID we have is running on docker
-- now, find the corresponding PID of the process on the VM  
for i in $(ps -ef | grep `docker inspect --format '{​​​​{​​​​.State.Pid}​​​​}​​​​' PostgreSQLCitus` | awk '{​​​​print $2}​​​​')  ; do grep NSpid: /proc/$i/status ; done | grep 6939
NSpid:    26857    6939


-- use gdb to connect to the PID on the VM
gdb -p 26857
(gdb) bt