enter the same img in docker in multiple console?

To run the same Docker image in multiple console or terminal windows, you essentially need to start a new container from that image in each console window. The process is fairly straightforward and similar across different operating systems, assuming you have Docker installed and set up correctly on your system.

Here's a step-by-step guide on how to do this:

1. Find or Pull Your Docker Image

   First, ensure you have the Docker image you want to run available on your local system. You can check this by listing all Docker images:

   docker images
   

   If the image isn't present, you can pull it from Docker Hub or any other Docker registry by using:

   docker pull <image_name>:<tag>
   

   Replace <image_name> with the name of the image you wish to use and <tag> with the version of the image, if applicable. If no tag is specified, latest is usually assumed.

2. Start a New Container in Each Console

   Open a new console window (or terminal window). In each window, you can run a command to start a new container instance from the image. The basic command to run a container is:

   docker run [OPTIONS] IMAGE [COMMAND] [ARG...]
   

   For example, if you want to run an interactive shell inside the container, you might use:

   docker run -it <image_name> /bin/bash
   

   The -it option allows you to interact with the container through your terminal. Replace <image_name> with the name of your Docker image. The /bin/bash part is optional and is used to specify that you want to start a bash shell inside the container; if the image uses a different shell or you want to start a different application, adjust this part accordingly.

3. Repeat for Additional Consoles

   For each additional console or terminal window in which you want to run the container, repeat the command from step 2. Each invocation of docker run creates and starts a new container instance based on the image specified.

Remember, each container runs in isolation by default. If you need the containers to communicate with each other or with the host, you may need to look into Docker networking options, such as port mapping (using the -p or --publish option) or creating a Docker network and attaching the containers to it.

This approach allows you to easily run multiple instances of the same Docker image in separate console windows, facilitating tasks such as testing, development, and debugging in isolated environments.

To ensure that your ROS 2 containers can communicate with each other correctly, including the rqt container discovering services, you need to ensure they share the same ROS 2 network. ROS 2 uses the DDS (Data Distribution Service) for its middleware, which by default might not be configured to work seamlessly across Docker containers due to networking isolation.

Here are steps to enhance communication and service discovery among your ROS 2 containers:

1. Use a common Docker network

Create a user-defined bridge network in Docker. This network facilitates better discoverability and communication among containers.

docker network create ros-network

When you run your containers, attach them to this network using the --network option:

docker run -it --rm \
    -e DISPLAY=192.168.2.9:0 \
    --network ros-network \
    my/ros:app \
    /bin/bash

2. ROS 2 Network Configuration

For ROS 2 to work properly across different containers, you might need to ensure that the DDS middleware is correctly configured for inter-host communication. One way to facilitate this is by setting appropriate environment variables in your containers that affect the DDS discovery mechanism.

Depending on the DDS implementation you're using (e.g., Fast-RTPS, Cyclone DDS, OpenSplice), you may need to set different environment variables. For example, with Fast-RTPS (the default in some ROS 2 versions), you might need to set FASTRTPS_DEFAULT_PROFILES_FILE to point to a configuration file that enables network interfaces or specifies the discovery method.

3. ROS_DOMAIN_ID

Ensure all your ROS 2 nodes across the containers are using the same ROS_DOMAIN_ID. This is an environment variable that segregates your ROS 2 communications:

docker run -it --rm \
    -e DISPLAY=192.168.2.9:0 \
    -e ROS_DOMAIN_ID=30 \
    --network ros-network \
    my/ros:app \
    /bin/bash

4. Check DDS Configuration and Firewall Rules

• Make sure your DDS configuration (depending on the implementation) is set up to allow for inter-container communication. This might involve configuring the DDS to use the right network interfaces or discovery protocols.
• Ensure your host machine's firewall is not blocking the communication. Docker's networking can sometimes be affected by host-level firewall settings.

5. Verify Time Synchronization

Ensure all your containers and the host machine are time-synchronized. ROS 2 and DDS can experience issues if the system times are significantly out of sync. You can achieve time synchronization by mounting the host's /etc/localtime in your containers:

docker run -it --rm \
    -e DISPLAY=192.168.2.9:0 \
    -e ROS_DOMAIN_ID=30 \
    --network ros-network \
    -v /etc/localtime:/etc/localtime:ro \
    my/ros:app \
    /bin/bash

Following these steps should enhance the discoverability and communication among your ROS 2 Docker containers, including the ability for rqt to discover services properly. If you continue facing issues, verify your DDS implementation's documentation for any additional configuration that might be necessary for cross-container communication.

If the two turtlesim containers are interacting correctly but rqt cannot discover services, it suggests that the basic ROS 2 communication infrastructure (like shared network and ROS_DOMAIN_ID) is set up correctly but there might be an issue specific to rqt or how service discovery works in your setup. Here are a few additional aspects to consider:

1. RQT Dependencies and Environment

Ensure that the rqt container has all necessary dependencies installed. rqt and its plugins might have additional dependencies beyond those required by basic ROS 2 nodes. If rqt was working previously in different setups but not in this containerized approach, it's less likely to be a dependency issue, but it's still worth verifying.

2. ROS 2 Version Compatibility

Check that all containers are running compatible ROS 2 distributions. While this is less likely to be an issue if you're using the same Docker image (my/ros:app) for all containers, discrepancies in ROS 2 versions or configurations might lead to communication issues, especially with more complex interactions like those needed for rqt.

3. Network and Discovery Configuration

While the DDS discovery should work across the ros-network Docker network, specific configurations or limitations of the DDS implementation might affect more complex interactions. Some DDS configurations allow for node discovery but might have issues with service discovery, especially in containerized environments.

• Explicitly Specify Discovery Peers: Some DDS implementations allow you to explicitly specify discovery peers. This can sometimes improve discovery in Docker environments. How you do this depends on the DDS implementation (e.g., environment variables for Fast RTPS).

• Check DDS Logs: Increase the verbosity of the DDS logs to check for any errors or warnings that might indicate why service discovery is not working as expected.

4. Using --privileged Mode

Running Docker containers in privileged mode (--privileged) can sometimes resolve communication issues by giving the container extended permissions. This is generally not recommended for production environments due to security implications but can help diagnose if the issue is related to container restrictions.

docker run -it --rm \
    -e DISPLAY=192.168.2.9:0 \
    -e ROS_DOMAIN_ID=30 \
    --network ros-network \
    --privileged \
    -v /etc/localtime:/etc/localtime:ro \
    my/ros:app \
    /bin/bash

5. Verify Multicast Configuration

DDS often relies on multicast for discovery. Docker's default bridge network supports multicast, but user-defined bridges (like ros-network) might have different behaviors depending on your Docker version and configuration. Ensure your network setup and DDS configuration support multicast as needed.

6. Diagnostics Tools

Use ROS 2 and DDS diagnostic tools to inspect the system state:

• Use ros2 doctor and ros2 node list to check for any warnings or errors and to see which nodes are visible.
• Use DDS-specific tools (depends on your DDS implementation) to inspect the discovery process.

Conclusion

If, after these checks, rqt still cannot discover services, the issue might require a deeper dive into the specific DDS configuration or potential limitations in how rqt interacts with ROS 2 services in a Dockerized environment. Reviewing rqt's logs and the DDS implementation's documentation for any known issues or limitations with Docker might provide further insights.

The message you're seeing when running rqt --list-plugins involves a couple of distinct issues, mostly related to the environment setup within your Docker container and the behavior of rqt and ROS plugins. Let's address these:

1. QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'

This warning is about the XDG_RUNTIME_DIR environment variable not being set. XDG_RUNTIME_DIR is used to specify a directory for storing runtime data for the current user. While this warning is generally harmless, you can avoid it by setting the XDG_RUNTIME_DIR environment variable in your Docker container. For example:

docker run -it --rm \
    -e DISPLAY=192.168.2.9:0 \
    -e ROS_DOMAIN_ID=30 \
    -e XDG_RUNTIME_DIR=/tmp/runtime-$(id -u) \
    --network ros-network \
    -v /etc/localtime:/etc/localtime:ro \
    my/ros:app \
    /bin/bash

Here, we set XDG_RUNTIME_DIR to a user-specific directory under /tmp. Adjust as necessary for your setup.

2. Warning about class_loader

This warning is a bit more complex. It's related to the way rqt and possibly other ROS tools manage dynamically loaded plugins. The class_loader warning indicates that there's an attempt to unload a dynamically loaded library (plugin) while there are still objects in memory that were created by this library. This can happen when the application (in this case, rqt) is shut down or when it tries to unload plugins, and it's not always indicative of a problem that will affect your use of rqt.

However, if you're experiencing issues with plugins not working correctly, or if rqt crashes, this warning might be related. Addressing it can be complex because it involves the order in which objects are destroyed and libraries are unloaded in the application's code, which is something only the developers can fix. If you suspect this is causing problems:

• Ensure you're using the latest version of rqt and related plugins, as this might be a known issue that has been fixed in newer versions.
• Consider reporting the issue to the ROS maintainers if it persists, providing them with details about your environment and how to reproduce the problem.

In many cases, these warnings can be safely ignored if they're not causing any observable issues with using rqt or other ROS tools. However, ensuring your Docker environment is correctly set up and keeping your ROS installation up-to-date can help minimize potential problems.

If the Services tab or specifically the Service Caller is not visible in your rqt setup, there could be several reasons for this. Here are steps to troubleshoot and potentially resolve the issue:

1. Ensure All Necessary Plugins Are Installed

The Service Caller is part of the rqt plugin system, and its availability can depend on having the correct ROS packages installed. To ensure you have all necessary plugins, including those for services, you might need to install additional ROS packages.

For ROS 2, ensure you have the relevant rqt packages installed. You can install common rqt tools, including the service caller, with:

sudo apt-get update
sudo apt-get install -y ros-<distro>-rqt* 

Replace <distro> with your ROS distribution name (e.g., foxy, galactic, humble).

2. Check Plugin List

After ensuring that all necessary packages are installed, run rqt --list-plugins to see if the Service Caller plugin is listed. This command lists all available rqt plugins. If the Service Caller is not listed, it indicates that the plugin is either not installed or there's an issue recognizing installed plugins.

3. Running rqt with Clean Environment

Sometimes, previous configurations can cause rqt to not load all plugins correctly. Try running rqt with a clean environment to see if this resolves the issue:

rqt --clear-config

This command forces rqt to ignore previous configurations and could potentially make the Service Caller plugin visible if a configuration issue was preventing it from loading.

4. Verify Environment Variables

Ensure that your ROS environment is properly set up, especially if you're running rqt from within a Docker container. Source the ROS setup files if you haven't:

For ROS 2:

source /opt/ros/<distro>/setup.bash

And ensure your environment variables, especially those related to ROS (like ROS_DOMAIN_ID and networking configurations), are correctly set for inter-container communication.

5. Check for Errors

When starting rqt, pay close attention to the terminal output for any error messages or warnings that could provide clues as to why the Service Caller plugin is not being loaded. Missing dependencies or errors in the plugin's initialization could prevent it from appearing in the rqt interface.

6. Compatibility Issues

Ensure that the version of rqt and its plugins are compatible with your ROS distribution. Incompatibilities can sometimes lead to plugins not loading correctly.

7. Manual Plugin Activation

Once rqt is running, try manually activating the plugin from the GUI:

• Go to Plugins > Services > Service Caller.
• If Services or Service Caller is not visible, it might not have been correctly installed or recognized by rqt.

If after following these steps, the Service Caller still does not appear, consider seeking support from the ROS community. There might be distribution-specific issues or bugs affecting the plugin system in rqt.

Given that rqt --list-plugins did not show any plugins and only displayed the warning you've mentioned earlier, it suggests there's a significant issue with the environment setup, plugin discovery, or potentially with the rqt installation itself. Here are several steps you can take to diagnose and hopefully resolve the issue:

1. Ensure Correct ROS Sourcing

First, ensure your ROS environment is sourced correctly. This is crucial for rqt and other ROS tools to function properly. Open a new terminal and source your ROS distribution:

For ROS 2, replace <distro> with your ROS 2 distribution (e.g., foxy, galactic, humble):

source /opt/ros/<distro>/setup.bash

2. Check for ROS Environment Issues

After sourcing, check if the ROS environment is set up correctly by running:

env | grep ROS

This command lists all environment variables related to ROS. Verify that variables like ROS_DISTRO, ROS_PYTHON_VERSION, and ROS_PACKAGE_PATH are set correctly.

3. Verify rqt and Dependencies Installation

If the ROS environment is correctly set up but rqt still fails to list any plugins, there might be an issue with the rqt installation or its dependencies. To ensure rqt and its common plugins are installed, run:

For ROS 2 (replace <distro> with your ROS 2 distribution):

sudo apt update
sudo apt install -y ros-<distro>-rqt ros-<distro>-rqt-common-plugins

4. Check Python Environment

rqt is a Python application, and issues with the Python environment can affect its operation. Make sure you're using the Python version expected by your ROS distribution. For ROS 2, this is typically Python 3.6 or newer. You can check your Python version with:

python --version

Or, for some systems:

python3 --version

5. Run rqt in Verbose Mode

Running rqt in verbose mode can provide more detailed output that might hint at the problem:

rqt -v

Look for any error messages or warnings that could indicate why plugins are not being discovered or loaded.

6. Check File Permissions

In some cases, file permissions or ownership issues can prevent rqt from accessing its plugins. Ensure your user has proper permissions to access ROS installation directories and the rqt plugin directories.

7. Using a Clean ROS Installation

If possible, try running rqt on a clean ROS installation, either on a different machine or in a clean Docker container. This can help determine if the issue is specific to your current setup.

8. Seek Community Help

If none of the above steps resolve the issue, consider seeking help from the ROS community. The ROS Answers website, ROS forums, or relevant GitHub issue trackers can be good places to ask for help. When seeking help, provide detailed information about your setup, the exact steps you've taken, and any error messages or warnings you've encountered.

Resolving issues like this often involves a process of elimination to narrow down the exact cause. Given the complexity of ROS and its dependency on the correct setup of the environment and dependencies, issues can sometimes stem from subtle misconfigurations.

If ROS_PACKAGE_PATH is not listed among the environment variables when you check with env | grep ROS, it might indicate that the ROS environment is not fully or correctly initialized. This can affect the operation of ROS tools, including rqt. Here's how you can address this issue:

1. Source the ROS Setup Script Again

Ensure that you source the ROS setup script for your specific ROS distribution every time you open a new terminal session. This is crucial for setting up the ROS environment correctly, including the ROS_PACKAGE_PATH.

For ROS 1 (replace <distro> with your ROS 1 distribution, e.g., melodic):

source /opt/ros/<distro>/setup.bash

For ROS 2 (replace <distro> with your ROS 2 distribution, e.g., foxy):

source /opt/ros/<distro>/setup.bash

After sourcing, check again with env | grep ROS to see if ROS_PACKAGE_PATH and other ROS-related environment variables appear.

2. Ensure Correct Installation

If sourcing the setup script does not resolve the issue, there might be a problem with your ROS installation. Ensure that ROS is correctly installed and that the ROS workspace (if you have one) is also correctly set up and built. For a ROS workspace, you would typically also source the setup.bash script located in the workspace's install or devel directory:

source ~/your_ros_workspace/install/setup.bash

Or, for a workspace built with catkin_make:

source ~/your_ros_workspace/devel/setup.bash

3. Verify ROS Installation

To check if ROS core packages are correctly installed and recognized, you can try listing ROS packages:

ros2 pkg list  # For ROS 2

Or for ROS 1:

rospack list

If this command does not list the expected ROS packages or returns an error, it confirms there's an issue with your ROS installation or environment setup.

4. Reinstall ROS (If Necessary)

If you suspect your ROS installation is corrupted or incomplete, consider reinstalling ROS. Follow the official installation instructions for your ROS distribution carefully:

• ROS 1 Installation Instructions
• ROS 2 Installation Instructions

5. Check for Workspace Overlays

If you are working with multiple ROS workspaces or have overlay workspaces on top of your base ROS installation, ensure they are sourced in the correct order. Sourcing a workspace setup script can overwrite the environment variables set by previously sourced workspaces, which can lead to issues if not done correctly.

6. Environment Variable Conflict

Check for any conflicting environment variable settings in your shell configuration files (such as .bashrc, .profile, or .bash_profile). An incorrect setting that overwrites ROS environment variables could be the cause of the problem.

By ensuring the ROS environment is correctly set up and that the ROS installation is complete and uncorrupted, you should be able to resolve issues with missing ROS_PACKAGE_PATH and related problems affecting rqt functionality.

Given that ros2 pkg list returns a lot of packages, it indicates that your ROS 2 installation itself seems to be in good order, and the core functionality of ROS 2 is operational on your system. The issue with rqt not listing any plugins, despite this, suggests a problem specific to rqt or its environment rather than a general ROS 2 installation issue.

Here's how to further troubleshoot and potentially resolve the rqt plugin visibility issue in a ROS 2 context:

1. Source ROS 2 Setup Script Again

Ensure that the ROS 2 environment is sourced correctly in every new terminal session. This is crucial for rqt and other ROS 2 tools:

source /opt/ros/<distro>/setup.bash

Replace <distro> with your ROS 2 distribution name (e.g., foxy, galactic, humble).

2. Check PYTHONPATH

rqt in ROS 2 might not use ROS_PACKAGE_PATH directly like ROS 1 does, but it relies on Python's package discovery mechanism. Ensure that your PYTHONPATH environment variable includes the paths to ROS 2 Python packages:

echo $PYTHONPATH

This should include paths within /opt/ros/<distro>/lib/python<version>/site-packages.

If PYTHONPATH does not seem correct, source the ROS 2 setup script again, and check if it corrects the PYTHONPATH.

3. Install rqt and Plugins

Although you've likely done this step, ensure that rqt and its common plugins are installed. Even if the base ROS 2 installation is correct, missing rqt plugins would cause the issue you're experiencing:

sudo apt update
sudo apt install -y ros-<distro>-rqt* 

4. Run rqt with Debug Information

Running rqt with debug information can sometimes provide more insights into what might be going wrong:

rqt --force-discover

or

rqt --force-discover -v

The -v flag increases verbosity, which might print more useful debug information to the terminal.

5. Check for Conflicting Environments

Ensure there's no conflicting software or Python environments that might interfere with rqt. For example, if you're using conda or other Python virtual environments, ensure they are deactivated:

conda deactivate

Or ensure that no other Python virtual environment is active.

6. Reinstall rqt

Consider reinstalling rqt and its plugins if the problem persists:

sudo apt remove ros-<distro>-rqt*
sudo apt autoremove
sudo apt install ros-<distro>-rqt-common-plugins

7. ROS 2 Overlay Workspaces

If you're working with ROS 2 overlay workspaces, ensure they are built correctly and sourced in the right order. A misconfigured overlay workspace could potentially shadow or conflict with the core rqt packages.

8. Seek Further Assistance

If the problem persists, consider seeking further assistance. The ROS Answers platform and the ROS 2 GitHub repositories can be good places to search for similar issues or to ask for help. Be sure to provide detailed information about your setup and the steps you've already tried.

By systematically checking these aspects, you should be able to narrow down and resolve the issue with rqt not listing any plugins in a ROS 2 environment.

If, after installing ros-<distro>-rqt-common-plugins, you see some rqt plugins (like a visualization plugin) but still cannot find the service plugin, it suggests that the installation of some rqt plugins was successful, but not all necessary plugins are present or correctly recognized by your environment. Here’s how you can further troubleshoot and attempt to resolve the missing service plugin issue:

1. Ensure Full Installation of RQT and Plugins

Although you've installed rqt-common-plugins, there might be other packages or dependencies that were missed. Make sure you've installed the full suite of rqt tools, which might include additional plugins not covered by the common plugins package:

sudo apt update
sudo apt install -y ros-<distro>-rqt*

This command attempts to install all rqt related packages for your ROS distribution.

2. Check Specific Package for Service Caller

The Service Caller plugin is part of the rqt_srv package. Ensure that this specific package is installed:

sudo apt install ros-<distro>-rqt-srv

Replace <distro> with your ROS distribution (e.g., foxy, galactic, humble).

3. Verify Plugin Discovery

After ensuring the installation, try forcing rqt to rediscover its plugins:

rqt --force-discover

4. Check for Errors

When launching rqt, especially with --force-discover, pay close attention to the terminal output for any error messages related to plugin discovery or loading. These messages can provide clues about what might be going wrong.

5. Run RQT in Verbose Mode

Running rqt in verbose mode might provide more detailed output, which could include useful information about why certain plugins are not being loaded:

rqt -v

6. Environment and Workspace

If you are working within a ROS workspace (especially an overlay workspace), ensure that it is properly built and sourced. Conflicts or issues with the workspace setup can lead to problems with finding or loading plugins.

• Rebuild your workspace:

  cd ~/your_workspace
  colcon build --symlink-install
  

• Source your workspace:

  source ~/your_workspace/install/setup.bash
  

• Then, try running rqt again.

7. Check Python Environment

Since rqt is a Python application, ensure that there are no conflicts with your Python environment. If you're using conda, virtualenv, or any other Python environment management tool, try deactivating these environments and running rqt with the system Python environment where ROS 2 is installed.

8. Consider ROS Answers or GitHub Issues

If you continue to face issues, consider seeking help on the ROS Answers forum or checking the GitHub issues for the rqt repository or ROS distribution you are using. When asking for help, provide detailed information about your ROS version, the steps you've taken, and any error messages you've encountered. This information will help others diagnose the issue more effectively.

Conclusion

The absence of the Service Caller plugin after installing rqt-common-plugins points to a specific issue with the plugin installation or discovery. By methodically going through the steps above, you should be able to identify and resolve the issue, enabling you to use the Service Caller plugin in rqt.

You're welcome! I'm glad to hear that the suggestion helped. Installing the full suite of rqt related packages with sudo apt update followed by sudo apt install -y ros-<distro>-rqt* is often a good approach to ensure you have all the necessary plugins and tools available for your work in ROS.

If you have any more questions or encounter further issues, whether it's about ROS, rqt, or anything else, feel free to ask. Happy coding and exploring with ROS!