ghactionsOGD

The goal of ghactionsOGD is to simplify the usage of Github Actions for small-scale data retrieval processes. A typical workflow would be to scrape data from a website on a daily basis and publish it as Open Government Data (OGD). In such a scenario the packages helps the user to set up the correct GitHub Actions Workflow including setting Actions Secrets and specifying the YAML Workflow file.

Since the package is only used for setting up the workflow, it does not need to be part of your dependencies on GitHub later on.

Installation

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

# install.packages("devtools")
devtools::install_github("ogdtg/ghactionsOGD")

Example

To create a workflow and set Actions Secrets that can be used in the R script you can use the following command. Before running the command you should have cloned the GitHub Repo to your local machine and you should run this command from within the cloned repo.

library(ghactionsOGD)
workflow <- create_ghactions_workflow(cron = "31 2 * * *",
                          name = "Test Run",
                          env = list(ODS_KEY = Sys.getenv("ODS_KEY")),
                          scripts = "test.R")

First, this command will produce the file .github/workflows/main.yml in your working directory (e.g. your local git repository). The file looks like this:

name: Test
'on':
  schedule:
    - cron: 31 2 * * *
  workflow_dispatch: ~
jobs:
  run_script:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout Repository
        uses: actions/checkout@v4
      - name: Execute Script
        run: Rscript test.R
        env:
          ODS_KEY: ${{ secrets.ODS_KEY }}
      - name: Set up Git
        run: |-
          git config --global --add safe.directory /__w/github_test/github_test
          git config --global user.name "GitHub Actions"
          git config --global user.email "[email protected]"
      - name: Check if there are changes to commit
        id: changes_check
        run: |-
          git add .
          if git diff-index --quiet HEAD; then
             echo "changes=false" >>$GITHUB_OUTPUT
          else
             echo "changes=true" >> $GITHUB_OUTPUT
          fi
      - name: Commit changes
        if: ${{ steps.changes_check.outputs.changes == 'true' }}
        run: git commit -m "Automated changes by GitHub Actions"
      - name: Push changes
        if: ${{ steps.changes_check.outputs.changes == 'true' }}
        run: git push
    container: rocker/tidyverse:4.1.2

Furthermore this command will set the necessary Actions Secrets. These can be used as environmental Variables in the R script. In this case you can use Sys.getenv("ODS_KEY") inside the test.R file an you will receive the value defined in the create_ghactions_workflow function.

YAML File

This YAML file represents a simple workflow which can be used to do small-scale data-retrieval tasks. For a better understanding the content will be discussde in more detail.

Event trigger

'on':
  schedule:
    - cron: 31 2 * * *
  workflow_dispatch: ~

This part defines, when the workflow should be triggered. Per default the create_ghactions_workflow adds a cron schedule that you can define in the function and a workflow_dispatch trigger. With this schedule, the workflow will be triggered every day at 2:31. The workflow_dispatch trigger allows you to trigger the workflow manually, which is useful for testing purposes.

Initialise Container

runs-on: ubuntu-latest
container: rocker/tidyverse:4.1.2

In this section the system is defined and the docker image that should be used. You can see a list of all rocker images here. You can also use your own image which has to be deployed on docker and must be publicly available.

Execute Script

- name: Execute Script
        run: Rscript test.R
        env:
          ODS_KEY: ${{ secrets.ODS_KEY }}

In this step the script is executed. Make sure that all needed packages are installed in the Image or in the script itself. I would recommend to use an image where all packages are preinstalled. This ensures stability and reproducability.

All variables that are defined in env must be stored as Actions Secrets. The create_ghactions_workflow takes care for this and initializes the Action secrets accordingly. You can find the Action Secrets on GitHub under Settings -> Secrets and Variables -> Actions

Push the Results to the Repo

      - name: Checkout Repository
        uses: actions/checkout@v4
      - name: Set up Git
        run: |-
          git config --global --add safe.directory /__w/github_test/github_test
          git config --global user.name "GitHub Actions"
          git config --global user.email "[email protected]"
      - name: Check if there are changes to commit
        id: changes_check
        run: |-
          git add .
          if git diff-index --quiet HEAD; then
             echo "changes=false" >>$GITHUB_OUTPUT
          else
             echo "changes=true" >> $GITHUB_OUTPUT
          fi
      - name: Commit changes
        if: ${{ steps.changes_check.outputs.changes == 'true' }}
        run: git commit -m "Automated changes by GitHub Actions"
      - name: Push changes
        if: ${{ steps.changes_check.outputs.changes == 'true' }}
        run: git push

To actually use the results your script you have to push them to the Repo you are running the Workflow in. Therefore you need to checkout your repository, set up git, add , commit and push the content.

There is also a functionality to check whether something has changed e.g. if a push is neccessary.

Acknowledgment

The package is using R functions internally imported directly from other R packages. The following R functions have been integrated as utilities functions:

• tic: gha_add_secret()
• ghactions: job(), step(), workflow()

All credits for these imported functions goes to the authors of the tic and ghactions R packages.