Docker Compose

Using the docker run command with many arguments could become convoluted, mainly when repeating the process regularly. This is when you should consider using Docker Compose to launch your container. Docker Compose is a wrapper for the run command that uses the YAML file. In addition, it enables the orchestration of multiple containers.

For example, the following docker run command launches a docker with RStudio Server inside a containerized environment:

docker run --rm -ti -v .:/home/rstudio -e PASSWORD=yourpassword -p 8787:8787 rocker/rstudio

Where we use the following arguments:

rm - Automatically remove the container when it exits
ti - Run the container in an interactive mode
v - Bind mount a volume, used to mount a local folder with the container
e - Set environment variables, used to define the login password to the RStudio Server
p - Defines the ports mapping

Here is how we going to populate the above run command inside a container:

docker-compose.yml

version: "3.9"
services:
  rstudio:
    image: "rocker/rstudio"
    ports:
      - "8787:8787"
    volumes:
      - type: "bind"
        source: "."
        target: "/home/rstudio"
    environment:
      - PASSWORD=yourpassword

The version argument defines the Docker Compose version, and the services enable the definition of multiple containers. In this case, we define a single container and name it as rstudio. As you can see, we used the ports, volumes, and environment arguments to map the p, v, and e arguments we used with the run command above respectively.

To launch the container - from the same folder of the docker-compose.yml file, use the docker-compose command:

docker-compose up

You should expect the following output:

[+] Running 2/2
 ✔ Network rstudio_default      Created                                                                                                                                                                          0.1s
 ✔ Container rstudio-rstudio-1  Created                                                                                                                                                                          0.1s
Attaching to rstudio-rstudio-1
rstudio-rstudio-1  | [s6-init] making user provided files available at /var/run/s6/etc...
rstudio-rstudio-1  | exited 0.
rstudio-rstudio-1  | [s6-init] ensuring user provided files have correct perms...
rstudio-rstudio-1  | exited 0.
rstudio-rstudio-1  | [fix-attrs.d] applying ownership & permissions fixes...
rstudio-rstudio-1  | [fix-attrs.d] done.
rstudio-rstudio-1  | [cont-init.d] executing container initialization scripts...
rstudio-rstudio-1  | [cont-init.d] 01_set_env: executing...
rstudio-rstudio-1  | skipping /var/run/s6/container_environment/HOME
rstudio-rstudio-1  | skipping /var/run/s6/container_environment/PASSWORD
rstudio-rstudio-1  | skipping /var/run/s6/container_environment/RSTUDIO_VERSION
rstudio-rstudio-1  | [cont-init.d] 01_set_env: exited 0.
rstudio-rstudio-1  | [cont-init.d] 02_userconf: executing...
rstudio-rstudio-1  | [cont-init.d] 02_userconf: exited 0.
rstudio-rstudio-1  | [cont-init.d] done.
rstudio-rstudio-1  | [services.d] starting services
rstudio-rstudio-1  | [services.d] done.

You can now open RStudio by login to http://localhost:8787 on your local browser:

Figure 1 - Running RStudio Server from the browser with Docker Compose

Note: The docker-compose up command we used above keeps the terminal attached to the container, and to stop the container use control+C. Alternatively, you can add the d argument to launch the container in detach mode running in the background:

docker-compose up -d

[+] Running 1/1
 ✔ Container rstudio-rstudio-1  Started

To stop the container, use down command:

docker-compose down

[+] Running 2/2
 ✔ Container rstudio-rstudio-1  Removed
 ✔ Network rstudio_default      Removed