README.md
In shiny2docker: Generate Dockerfiles for 'Shiny' Applications

shiny2docker

shiny2docker is an R package designed to streamline the process of containerizing Shiny applications using Docker. By automating the generation of essential Docker files and managing R dependencies with renv, shiny2docker simplifies the deployment of Shiny apps, ensuring reproducibility and consistency across different environments.

Automated Dockerfile Generation: Quickly generate Dockerfiles tailored for Shiny applications. The main function, shiny2docker(), creates a Dockerfile using a renv.lock file to capture your R package dependencies.
Dependency Management: Utilize renv to manage and restore R package dependencies. If a lockfile does not exist, shiny2docker() will automatically create one for production using the attachment::create_renv_for_prod function.
Customizability: The shiny2docker() function returns a dockerfiler object that can be further manipulated using dockerfiler’s methods before writing it to a file. This enables advanced users to customize the Dockerfile to better suit their needs. See dockerfiler for more details.
GitLab CI Integration: With the set_gitlab_ci() function, you can easily configure your GitLab CI pipeline. This function copies a pre-configured gitlab-ci.yml file from the package into your project directory. The provided CI configuration is designed to build your Docker image and push the created image to the GitLab container registry, thereby streamlining continuous integration and deployment workflows.
GitHub Actions Integration: With the set_github_action() function, you can quickly set up a GitHub Actions pipeline. This function copies a pre-configured docker-build.yml file from the package into the .github/workflows/ directory of your project. The provided CI configuration is designed to build your Docker image and push the created image to the GitHub Container Registry, facilitating automated builds and deployments on GitHub.

You can install the production version from CRAN with :

install.packages("shiny2docker")

You can install the development version of shiny2docker from GitHub with:

# install.packages("pak")
pak::pak("VincentGuyader/shiny2docker")

Use the shiny2docker() function to automatically generate a Dockerfile based on your application’s dependencies.

library(shiny2docker)

# Generate Dockerfile in the current directory
shiny2docker(path = ".")

# Generate Dockerfile with a specific renv.lock and output path
shiny2docker(path = "path/to/shiny/app",
             lockfile = "path/to/shiny/app/renv.lock",
             output = "path/to/shiny/app/Dockerfile")

# Further manipulate the Dockerfile object before writing to disk
docker_obj <- shiny2docker()
docker_obj$ENV("MY_ENV_VAR", "value")
docker_obj$write("Dockerfile")

The set_gitlab_ci() function allows you to quickly set up a GitLab CI pipeline that will build your Docker image and push it to the GitLab container registry.

library(shiny2docker)

# Copy the .gitlab-ci.yml file to the current directory
set_gitlab_ci()

The new set_github_action() function allows you to quickly set up a GitHub Actions pipeline that will build your Docker image and push it to the GitHub Container Registry.

library(shiny2docker)

# Copy the docker-build.yml file to the .github/workflows/ directory
set_github_action(path = ".")

Once the docker-build.yml file is in place, you can integrate it with GitHub Actions to automate the Docker image build and deployment process.

Prepare Your Shiny Application: Ensure that your Shiny app is located in a folder with the necessary files (e.g., app.R or ui.R and server.R).
Generate the Dockerfile: Run shiny2docker() to create the Dockerfile (and a .dockerignore file) in your project directory. This Dockerfile will include instructions to install system dependencies, R packages, and launch the Shiny app.
Set Up Continuous Integration (Optional):
- If you use GitLab, run set_gitlab_ci() to copy the pre-configured GitLab CI file into your project. This CI configuration will handle the Docker image build and deployment to GitLab’s container registry.
- If you use GitHub, run set_github_action(path = ".") to copy the pre-configured GitHub Actions file into your project. This CI configuration will build your Docker image and push it to the GitHub Container Registry.
Deploy Your Application: Use Docker to build and run your image, or integrate with your chosen CI/CD service for automated deployments.