I am working on a Gatsby site which sources my weight data from a google spreadsheet to generate a site which shows my weight trend. The spreadsheet is updated every morning, typically at 06:00, where I record my weight.

Netlify does not automatically build and deploy when the spreadsheet is updated, since Netlify does not know that the spreadsheet is updated. The simplest approach is to schedule a build and deployment of the Gatsby site every day, such that new weight data is automatically sourced, deployed and thus made public.

Netlify does not provide any means to schedule deployments. As far as I can see, Netlify only supports git push triggering and build hooks. Build hooks are an unique URL triggered by, e.g. Curl, starting a new build & deploy.

This hook can be called in a schedule manner, thus enforcing a scheduling of the build and deployment in Netlify.

The simplest approach I have found is to use Github actions to invoke the build hook with Curl. The following action calls the web hook every day at 8:00 UTC.

name: Every day

on:
  schedule:
    - cron: "0 8 * * *"
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - name: POST hook
      run: curl -X POST -d {} https://api.netlify.com/build_hooks/{UNIQUE_HOOK_ID}

With this in place, Github will trigger a build & deploy in Netlify without requiring any push to the repository.

Containers are now first class citizens in App Services. A Container App Service can be created with a specific image that is pulled from DockerHub or other registry.

Pulling the image only happens when the App Service is started or restarted. Pulling the image automatically seems not to be supported, meaning that one has to manually restart the App Service every-time the image has been updated and needs to be re-pulled.

Luckily, App Service exposes a Webhook which will pull the latest image and restart the container if necessary. This can be enabled by setting Continuous Deployment to On. Afterwards, the Webhook URL can be copied and used as part of a CI/CD pipeline.

The URL has the form:

https://${appservicename}:{password}@{appservicename}.scm.azurewebsites.net/docker/hook

The webhook uses basic authentication. POSTing to the URL will pull the latest image. curl can be used for this purpose as such:

curl --data '' https://\${appservicename}:{password}@{appservicename}.scm.azurewebsites.net/docker/hook

Note: Remember to escape the dollar sign if using a Bash Shell

For CI/CD, this can be easily integrated. Example from one of my github projects:

name: Dockerize
on: [push]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v1
    - name: Login to Docker
      run: docker login -u ${{secrets.DOCKER_USERNAME}} -p ${{secrets.DOCKER_PASSWORD}}
    - name: Build the Docker image
      run: docker build . --file Dockerfile --tag horup/outfitty:latest --tag horup/outfitty:$(date +%s)
    - name: Push the Docker image
      run: docker push horup/outfitty
    - name: Trigger App Service
      run: "curl --data '' ${{secrets.APP_SERVICE_WEBHOOK_URL}}"

Here, the last step posts empty data to the Webhook URL. Note that the URL is kept in a secret in Github due to it containing basic authentication credentials. Also remember to escape the dollar sign when keeping this as a secret.

That’s it!