I am following the simple Docker tutorial and coming across “ERROR: Unable to communicate with master!”. Here’s the output :
dparkar@dupin:~ docker pull ros
Using default tag: latest
latest: Pulling from library/ros
6b98dfc16071: Pull complete
4001a1209541: Pull complete
6319fc68c576: Pull complete
b24603670dc3: Pull complete
97f170c87c6f: Pull complete
979f74553e2f: Pull complete
2413da49cb9d: Pull complete
652985201ab5: Pull complete
e828be34f7aa: Pull complete
308b41b91982: Pull complete
f2de7c187505: Pull complete
76d678fbdf1b: Pull complete
8a4ec92e7e79: Pull complete
25e2b1ab5d6f: Pull complete
Digest: sha256:842160e6c266f3853b190d7f10e223fcaf4f1ead1852976aa529082d0b0bbcb6
Status: Downloaded newer image for ros:latest
dparkar@dupin:~ docker run -it ros
root@a245a8c57fbe:/# docker ps -l
bash: docker: command not found
root@a245a8c57fbe:/# source /opt/ros/melodic/setup.bash
root@a245a8c57fbe:/# rostopic list
ERROR: Unable to communicate with master!
root@a245a8c57fbe:/#
Appreciate any pointers.