docker

Using iceoryx2 in A Docker Environment

Introduction

Let's assume we have a setup where the publisher and the subscriber are running in their own docker containers. We use the publish_subscribe as base.

Our setup looks like:

                    +------------------------------+
                    | host                         |
                    |                              |
                    | publish_subscribe_subscriber |
                    +------------------------------+
                       ^
                  send | data
                       |
 +-----------------------------+         +------------------------------+
 | docker 1                    |  send   | docker 2                     |
 |                             |-------->|                              |
 | publish_subscribe_publisher |  data   | publish_subscribe_subscriber |
 +-----------------------------+         +------------------------------+

On our host we would like to run a subscriber, on docker container 1 a publisher that can send data to the subscriber in docker container 2 and to the host.

Requirements

iceoryx2 discovers services by parsing the service toml files in the /tmp/iceoryx2 directory and communicates via shared memory that is located in /dev/shm. If both directories are available in every docker container and are shared with the host, iceoryx2 can establish a connection between them.

How to Run

We start three separate terminals. We use archlinux:latest in this example but you are free to choose any other linux distribution.

We start by building the example:

cargo build --example publish_subscribe_publisher
cargo build --example publish_subscribe_subscriber

Create the directory /tmp/iceoryx2 so that it can be mounted into the docker container. iceoryx2 creates it automatically but in our case we start the container before we start iceoryx2, therefore we have to create it manually.

mkdir /tmp/iceoryx2

Now open the terminals.

Terminal 1 (docker 1)

docker run --mount type=bind,source="/dev/shm",target=/dev/shm --mount \
    type=bind,source=/home/$USER$/iceoryx2,target=/iceoryx2 --mount \
    type=bind,source=/tmp/iceoryx2,target=/tmp/iceoryx2 -it archlinux:latest

cd /iceoryx2
./target/debug/examples/publish_subscribe_publisher

Terminal 2 (docker 2)

docker run --mount type=bind,source="/dev/shm",target=/dev/shm --mount \
    type=bind,source=/home/$USER$/iceoryx2,target=/iceoryx2 --mount \
    type=bind,source=/tmp/iceoryx2,target=/tmp/iceoryx2 -it archlinux:latest

cd /iceoryx2
./target/debug/examples/publish_subscribe_subscriber

Terminal 3 (host)

Docker is mostly started as root and therefore all the shared memory segments and service files are created under the root user. We use sudo to be able to subscribe to the docker services.

cd iceoryx2
sudo ./target/debug/examples/publish_subscribe_subscriber

docker-compose Example

We can also use docker-compose to start our test setup. Our example is coming with a configuration file docker-compose.yml which can be used from the iceoryx root path with the following command:

mkdir /tmp/iceoryx2
docker-compose -f examples/rust/docker/docker-compose.yml --project-directory . up

We can again open a new terminal and start an additional publisher or subscriber with root privileges and connect to the docker containers.

cd iceoryx2
sudo ./target/debug/examples/publish_subscribe_publisher