How to use ROS in Colab?

edit

I built on the answer above and added a run script that sets the ROS_MASTER_URI and sources the ROS environment. It has to be run in each cell, but this seems to work.

!sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'

!sudo apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654

!sudo apt update

!sudo apt install ros-melodic-desktop-full

!pip install --extra-index-url https://rospypi.github.io/simple/ rospy

import rospy
### wait, we need a master:
!echo ""
!printf -- '#!/bin/bash\n' > ros_start.sh
!printf -- 'source /opt/ros/melodic/setup.bash\n' >> ros_start.sh
!printf -- '/opt/ros/melodic/bin/roscore' >> ros_start.sh
!chmod +x ros_start.sh
!cat ros_start.sh

# Create a utility to set ROS_MASTER_URI and source the environment.
with open("run",'w') as f:
  f.write('#!/bin/bash\n')
  f.write('ROS_MASTER_URI="0.0.0.0"\n')
  f.write('source /opt/ros/melodic/setup.bash\n')
  f.write('exec $@\n')

f.close()
!chmod +x run
!echo ""
!cat run

Once this executes, one can then do the following:

import subprocess
import os
prc = subprocess.Popen([os.getcwd()+"/ros_start.sh"])
# Init the cell with 'run'
!./run
###now we have a master!
rospy.get_published_topics()

--

[['/rosout_agg', 'rosgraph_msgs/Log']]

Or you can execute ROS command line arguments like this:

!./run rostopic list
/rosout
/rosout_agg

And here is an example creating a node, publisher and subscriber: [Although I admit, I am not sure why I'm getting doublets of messages.]

!./run

from std_msgs.msg import String

rospy.init_node('test_node')
P = rospy.Publisher('/test',String,queue_size=10)
def testcb(data):
  print("Got %s" % data.data)

S = rospy.Subscriber('test', String, callback=testcb)

for i in range(10):
  P.publish(str(i))

-

WARNING: cannot load logging configuration file, logging is disabled
Got 0
Got 0
Got 1
Got 1
Got 2
Got 2
Got 3
Got 3
Got 4
Got 4
Got 5
Got 5
Got 6
Got 6
Got 7
Got 7
Got 8
Got 8
Got 9
Got 9

Well, a colab notebook is basically a docker instance, so you can install ROS in a colab notebook!

What I did:

!sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'

!sudo apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654

!sudo apt update

!sudo apt install ros-melodic-desktop-full

!pip install --extra-index-url https://rospypi.github.io/simple/ rospy

import rospy
### wait, we need a master:

!printf -- '#!/bin/bash\n' > ros_start.sh
!printf -- 'source /opt/ros/melodic/setup.bash\n' >> ros_start.sh
!printf -- '/opt/ros/melodic/bin/roscore' >> ros_start.sh
!chmod +x ros_start.sh
!cat ros_start.sh

import subprocess
import os
prc = subprocess.Popen([os.getcwd()+"/ros_start.sh"])

Here (as pointed out by shandilya1998 and Gustavo Lima) you need to wait a bit since subprocess is asynchronous and the master will take some time to load.

###when we have a master the following line should work.
rospy.get_published_topics()

Here is the gist for it, if you want to try it out yourself. https://gist.github.com/frederico-kle...