From Hello World to Image display

Last week I had worked on creating an interface for ROS1 and ROS2 and created a dummy library for publishing ‘Hello World’. This week I had to modify that interface to display image by uniting with image drivers.

Also it was discussed that we cannot switch the environment at runtime in c++ build currently so we should move to docker. Another task this week was to create different Dockerfiles.

docker

Wrapper for image display

First I used my current interface for publishing the image. Initially I used the example given in ROS tutorials for displaying an image from a given path. This worked fine so next I moved to getting images from webcam. Gradually I moved individual subscriber nodes also to the interface.

When running this code from ROS1 I am getting this kind of image.

ros1-camera

I looked into the issue of green background in ….{} but could not solve it yet. I will look more into it.

ROS2 driver which was created before the GSoC period and improved in first week was used here. That was created in ROS2-Crystal but in this distro (Dashing), this code was giving errors due to changed conventions so firstly This code was corrected. This can be accessed in ROS2-Image driver.

With ROS2 the interface is working well.

Complete video can be watched by clicking on the image.

ROS1-ROS2-Camera

Steps to run this interface:

mainpub.cpp: Publisher in this interface

mainsub.cpp: Subscriber in this interface

  • ROS

    • Delete all previously buid and cache folders

    • First Build the project: colcon build --symlink-install \--cmake-args \ -Drosversion:string=1

    string = 1 for for ROS1

    Run:

    • For Publishing image ./build/camera-interface/mainpub 1 2

    argv[1] = 1 For ROS1 argv[2] = 2 (For selecting video device. In my Laptop device number 2 givs fine video stream.)

    • For Listening to image ./build/camera-interface/mainsub 1 /camserver/rgb

    argv[1] = 1 For ROS1 argv[2] = /camserver/rgb (For selecting the right topic to subscribe to)

  • ROS2

    • Delete all previously buid and cache folders

    • First Build the project: colcon build --symlink-install \--cmake-args \ -Drosversion:string=0

    string = 0 for ROS2

    • Run ./build/camera-interface/mainpub 2

    argv[1] = 2 For ROS2

    • For Listening to image ./build/camera-interface/mainsub 2 /camserver/rgb

    argv[1] = 2 For ROS2 argv[2] = /camserver/rgb (For selecting the right topic to subscribe to)

Further improvement in architecture

Further improvement should be made in this code architecture to bring uniformity in both ROS and ROS1. Current architecture in using a jdrc pointer variable and prefix. After correcting these two errors:

  • Green background in images

  • reading configurations from yaml file

mainpub.cpp:(.text+0x453): undefined reference to `YAML::LoadFile(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I might modify the code further.

Progress in DOCKER FILES

My task this week was to create dockerfiles for 3 different environments

  • ROS1

  • ROS2

  • ROS1+ROS2

Since, I wasn’t familiar with docker earlier I watched the suggested videos Docker , Docker-compose and documentation to learn the basics.

Now, I used the existing images to create different environments.

  1. ROS Melodic

Dockerfile can be found in ROS-Melodic dockerfile

Here is an image of a talker and listener node running with master via docker

ros-melodic

  1. ROS Dashing Dockerfile can be found in ROS-Melodic dockerfile

  2. ROS Melodic + ROS Dashing

  • Approach 1 : multi-stage Dockerfile

Meged the content of both docker files. Basically ‘multiple FROM’ statements to get the existing images from ROS

Result: Fail. It turned into the environment of the Distro which was there in the last ‘FROM..’ installation statements in Dockerfile.

  • Approach 2

Multi Containers with Docker-compose

Link to Docker file: docker-file

Status:

Build: sudo docker-compose build

pankhuri@pankhuri-LENOVO-IDEAPAD-500-15ISK:~/Docker/compose-ros/compose$ sudo docker-compose build
Building ros-melodic
Step 1/12 : FROM ubuntu:bionic
 ---> 7698f282e524
Step 2/12 : RUN apt update
 ---> Using cache
 ---> 568646da8ec6
Step 3/12 : RUN apt-get install -y lsb-release
 ---> Using cache
 ---> e596418dd9b3
Step 4/12 : RUN apt-get update && apt-get install -y gnupg2
 ---> Using cache
 ---> c286b7ad7497
Step 5/12 : RUN sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
 ---> Using cache
 ---> 78d04a1323e3
Step 6/12 : RUN apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
 ---> Using cache
 ---> f299aab835d2
Step 7/12 : RUN apt update
 ---> Using cache
 ---> 17d94468b7a1
Step 8/12 : RUN apt-get install -y tzdata
 ---> Using cache
 ---> 0edf53f0acb2
Step 9/12 : RUN apt install -y ros-melodic-desktop-full
 ---> Using cache
 ---> 7cd5b422f162
Step 10/12 : RUN apt install -y python-rosinstall python-rosinstall-generator python-wstool build-essential
 ---> Using cache
 ---> 317774ee917a
Step 11/12 : RUN rosdep init
 ---> Using cache
 ---> 0817ce31cb84
Step 12/12 : RUN rosdep update
 ---> Using cache
 ---> 1cab27d973e2

Successfully built 1cab27d973e2
Successfully tagged compose_ros-melodic:latest
Building ros-dashing
Step 1/12 : FROM ubuntu:bionic
 ---> 7698f282e524
Step 2/12 : RUN apt update
 ---> Using cache
 ---> 568646da8ec6
Step 3/12 : RUN apt update
 ---> Using cache
 ---> 00045212a5ec
Step 4/12 : RUN apt-get -y install lsb-release
 ---> Using cache
 ---> ebe7739f5832
Step 5/12 : RUN apt install -y curl gnupg2 lsb-release
 ---> Using cache
 ---> 08e7835374cb
Step 6/12 : RUN curl http://repo.ros2.org/repos.key | apt-key add -
 ---> Using cache
 ---> 39571bff8738
Step 7/12 : RUN sh -c 'echo "deb [arch=amd64,arm64] http://packages.ros.org/ros2/ubuntu `lsb_release -cs` main" > /etc/apt/sources.list.d/ros2-latest.list'
 ---> Using cache
 ---> 008a3501d19f
Step 8/12 : RUN apt update
 ---> Using cache
 ---> e2507e06a78f
Step 9/12 : RUN apt-get install -y tzdata
 ---> Using cache
 ---> 2e5d879aa103
Step 10/12 : RUN apt install -y ros-dashing-desktop
 ---> Using cache
 ---> 15899903dddf
Step 11/12 : RUN apt install -y python3-argcomplete
 ---> Using cache
 ---> b660771fbba1
Step 12/12 : RUN apt update
 ---> Using cache
 ---> 0b9120516da4

Successfully built 0b9120516da4
Successfully tagged compose_ros-dashing:latest

Start sudo docker-compose up

pankhuri@pankhuri-LENOVO-IDEAPAD-500-15ISK:~/Docker/compose-ros/compose$ sudo docker-compose up
Starting compose_ros-melodic_1 ... done
Starting compose_ros-dashing_1 ... done
Attaching to compose_ros-melodic_1, compose_ros-dashing_1
compose_ros-dashing_1 exited with code 0
compose_ros-melodic_1 exited with code 0

So, we can see it exits right from here.

pankhuri@pankhuri-LENOVO-IDEAPAD-500-15ISK:~/Docker/compose-ros/compose$ sudo docker-compose ps
        Name             Command    State    Ports
--------------------------------------------------
compose_ros-dashing_1   /bin/bash   Exit 0        
compose_ros-melodic_1   /bin/bash   Exit 0

For executing: sudo docker exec -it compose_ros-melodic_1 /bin/bash`

pankhuri@pankhuri-LENOVO-IDEAPAD-500-15ISK:~/Docker/compose-ros/compose$ sudo docker exec -it compose_ros-melodic_1 /bin/bash
Error response from daemon: Container 3bda7fdfa704745fe9cdf738c06adae18410d83f7cf40a44330fb7a67fe6608f is not running

Using sudo docker-compose images

      Container             Repository         Tag       Image Id      Size  
-----------------------------------------------------------------------------
compose_ros-dashing_1   compose_ros-dashing   latest   0b9120516da4   2.29 GB
compose_ros-melodic_1   compose_ros-melodic   latest   1cab27d973e2   2.76 GB

Running one container sudo docker run -t 0b9120516da4 

root@26926e9d45ff:/#

Links which were referred: Docker Compose

  • Approach 3 Multi-Conatiners with Entrypoints

  • Approach 4 Download both ROS distros and keep separate Entrypoints Github-link

I could not reach to final solution from any of the approaches mentioned above

I think I am close to the right thing but discussing this issue with the mentors in this week’s meeting would help in moving ahead with finishing it.